AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

GENERAL PRINCIPLES

Section 2 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Stedman's Medical Dictionary, 27th Edition defines acute abdomen as "any serious acute intra-abdominal condition attended by pain, tenderness, and muscular rigidity, and for which emergency surgery must be considered."

The approach to pregnant patients with severe abdominal pain is very similar to that for nonpregnant patients with acute abdomen. However, the physiologic changes associated with pregnancy must be considered when interpreting findings from the history and physical examination.

History

Obtain as detailed a history as possible regarding the time of onset, duration, intensity, and character of the pain and any associated symptoms. Establishing the gestational age early in the evaluation is essential because the likelihood of different etiologies changes with different gestational ages. Accurate knowledge of gestational age is required to make appropriate decisions regarding fetal viability and the need for fetal evaluation. Remember that nausea, vomiting, constipation, increased frequency of urination, and pelvic or abdominal discomfort are frequently experienced in normal pregnancy. Ask the patient to differentiate these normal pregnancy changes from the acute event for which she presents.

Also, ascertain the time course and acuteness of onset.

• Did the pain begin suddenly or did it grow in intensity?
• Is it steady or crampy, dull and aching, or sharp and stabbing?
• Did it occur before or after a meal?
• Did it awaken the patient from sleep?
• How well is it localized, and has the location changed?
• Is it associated with nausea and vomiting; and, if so, did these begin before or after the pain?
• Does anything make the pain worse, or make it better?

Physical examination

Upon physical examination, findings may be less prominent compared to those of nonpregnant patients with the same disorder (Cunningham, 1975; McGee, 1989) Peritoneal signs are often absent in pregnancy because of the lifting and stretching of the anterior abdominal wall. The underlying inflammation has no direct contact with the parietal peritoneum, which precludes any muscular response or guarding that would otherwise be expected (Sivanesaratnam, 2000). The uterus can also obstruct and inhibit the movement of the omentum to an area of inflammation, distorting the clinical picture.

To help distinguish extrauterine tenderness from uterine tenderness, performing the examination with the patient in the right or left decubitus position, thus displacing the gravid uterus to one side, may prove helpful. When performing a physical examination of the gravid abdomen, it is essential to recall the changing positions of the intra-abdominal contents at different gestational ages. For example, the appendix is located at the McBurney point in patients in early pregnancy and in nonpregnant patients. After the first trimester, the appendix is progressively displaced upward and laterally, until it is closer to the gallbladder in late pregnancy (Baer, 1932). Such alterations in physical assessment can delay diagnosis, and many authorities attribute the increased morbidity and mortality of acute abdomen in gravid patients to this delay.

When evaluating the gravid patient, the clinician must evaluate 2 patients at the same time, the mother and the fetus. Before the gestational age at which independent viability (if delivery were to occur) is generally expected evaluation of the fetus can be limited to documentation of the presence or absence of fetal heart tones by Doppler or ultrasound. When the fetus is considered viable, a more thorough evaluation is required. The age of viability varies from institution to institution. Monitor the fetal heart rate and uterine tone continuously throughout the period of evaluation.

A nonreassuring tracing or evidence of fetal distress may suggest an obstetric etiology for the acute abdomen (eg, placental abruption, uterine rupture). A reassuring tracing allows the evaluation to continue at an appropriate pace. Monitoring for uterine contractions throughout the evaluation period and even after definitive treatment is important. A strong correlation is observed between intra-abdominal infectious or inflammatory processes and preterm labor and delivery.

Laboratory evaluation

When evaluating the gravid patient with acute abdominal pain, remember that some very commonly used laboratory tests have altered reference ranges in pregnancy. These changes can make the initial evaluation process somewhat more difficult. For example, an inflammatory process such as appendicitis would be expected to produce an elevated white blood cell count. Yet, pregnancy alone can produce white blood cell counts ranging from 6000-16,000/mm³ in the second and third trimesters and from 20,000-30,000/mm³ in early labor (Pritchard, 1962).

Ultrasound

Ultrasound is probably the most frequently used radiologic modality for evaluating a pregnant abdomen. Extensive experience documents the safety of ultrasound in pregnancy. The maternal gallbladder, pancreas, and kidneys can be evaluated easily. Ultrasound is also used with graded compression as a diagnostic aid for appendicitis. The size of the gravid abdomen may limit this approach in pregnancy, but some researchers have reported success (Puylaert, 1987; Lim, 1992). The use of ultrasound is essential for fetal evaluation. Ultrasound helps to establish gestational age and fetal viability, to exclude congenital anomalies, and to assess amniotic fluid volume and fetal well-being. This information may become critical later in the management of a gravid patient with an acute abdomen, when decisions regarding delivery, mode of delivery, and the use of tocolytics and steroids must be made.

Radiographs

While ionizing radiation in the evaluation of patients who are pregnant is often a source of anxiety for the practicing clinician, radiograph exposure from a single diagnostic procedure does not result in harmful fetal effects.

Estimated Fetal Exposure From Some Common Radiologic Procedures

*Exposure depends on the number of films. (Table is from the American College of Obstetricians and Gynecologists, 1995.)

If multiple diagnostic procedures are needed, remember that exposure to less than 0.05 Gy has not been associated with an increase in fetal anomalies or pregnancy loss. During pregnancy, perform medically indicated diagnostic radiograph procedures when needed, but consider other imaging procedures not associated with ionizing radiation instead of radiographs when possible (American College of Obstetricians and Gynecologists, 1995). Due to the possible association of prenatal radiation exposure with childhood cancer (Harvey, 1985), use ionizing radiation only when medically necessary and minimize that exposure when possible, without compromising patient care.

Magnetic resonance imaging

MRI uses magnets rather than ionizing radiation to alter the energy state of hydrogen protons. This may prove useful in the evaluation of the maternal abdomen and of the fetus. Although no adverse fetal effects have been documented, the National Radiological Protection Board arbitrarily advises against the use of MRI in the first trimester (Garden, 1991). Not all MRI contrast agents are approved for use in pregnancy. In a recent series, MRI was found useful in the diagnosis of acute appendicitis when ultrasound was inconclusive (Pedrosa et al, 2006).

Differential diagnosis

Acute abdomen, as it presents with pregnancy, has many possible causes. Clearly, the case of a pregnant patient with acute abdomen is a clinical scenario that overlaps specialties. Do not hesitate to involve a surgeon, obstetrician/gynecologist, and a specialist in maternal-fetal medicine when dealing with this challenging situation. Any cause for acute abdomen can occur coincident with pregnancy. Some clinical conditions are more likely to occur in pregnancy. Other conditions are specific to pregnancy. Thus, a wide range of possible differential diagnoses should be considered.

Incidental to pregnancy

• Gastrointestinal
• • Acute appendicitis
  • Acute pancreatitis
  • Peptic ulcer
  • Gastroenteritis
  • Hepatitis
  • Bowel obstruction
  • Bowel perforation
  • Herniation
  • Meckel diverticulitis
  • Toxic megacolon
  • Pancreatic pseudocyst
  • Toxic megacolon
• Genitourinary
• • Ovarian cyst rupture
  • Adnexal torsion
  • Ureteral calculus
  • Rupture of renal pelvis
  • Ureteral obstruction
• Vascular
• • Superior mesenteric artery syndrome
  • Thrombosis/infarction - Specifically mesenteric venous thrombosis
  • Ruptured visceral artery aneurysm
  • Splenic artery aneurysm
• Respiratory
• • Pneumonia
  • Pulmonary embolism
• Other
• • Intraperitoneal hemorrhage
  • Splenic rupture
  • Abdominal trauma
  • Acute intermittent porphyria
  • Diabetic ketoacidosis
  • Sickle cell disease

Conditions associated with pregnancy

• Acute pyelonephritis
• Acute cystitis
• Acute cholecystitis
• Acute fatty liver of pregnancy
• Rupture of rectus abdominus muscle
• Torsion of the pregnant uterus

Due to pregnancy

• Early pregnancy
• • Ruptured ectopic pregnancy
  • Septic abortion with peritonitis
  • Acute urinary retention due to retroverted gravid uterus
• Later pregnancy
• • Red degeneration of myoma
  • Torsion of pedunculated myoma
  • Placental abruption
  • Placenta percreta
  • HELLP (hemolysis, elevated liver function, and low platelets) syndrome – Spontaneous rupture of the liver
  • Uterine rupture
  • Chorioamnionitis

Treatment

Treatment of acute abdomen in pregnancy depends on the specific diagnosis. Indications for emergency surgery are the same for patients who are pregnant as they are for any other patients. If surgery is required but is considered elective, waiting until after the pregnancy is completed is prudent. If surgery is deemed necessary during pregnancy, perform it in the second trimester if possible; the risk of preterm labor and delivery is lower in the second trimester compared to the third, and the risk of spontaneous loss and risks due to medications such as anesthetic agents are lower in the second trimester compared to the first.

Laparoscopy during pregnancy

Laparoscopy has become increasingly popular in the treatment and evaluation of acute abdomen. In the past, pregnancy was considered a contraindication for laparoscopy, although multiple reports of the successful use of diagnostic and therapeutic laparoscopy have been published more recently (Mazze, 1989; Gadacz, 1991).

The Hasson technique, an open approach to entering the abdomen, has been suggested to avoid potential injury to the gravid uterus with the Veress needle or trocar. Advantages of laparoscopy over laparotomy include shortened hospital stay, less need for narcotics, easier postoperative ambulation, and earlier tolerance of oral intake postoperatively. Care must be taken to minimize manipulation of the uterus. Adjust the location of trocar placement based on uterine size. Monitor fetal heart tones during the surgical procedure. The surgeon must work closely with the obstetrician to maintain fetal well-being during the surgical procedure. An experienced laparoscopist is important to keep surgical times as short as possible (Gurbuz, 1997). Although generally accepted as safe, reports of fetal demise after laparoscopy continue to occur in the literature (Carver et al, 2005).

Obstetrical concerns

Preterm labor and delivery is the most significant threat to the fetus in the management of acute maternal intra-abdominal disease. Insufficient data are available to quantitate the risk, but the severity of the disease process appears to be a major determinant of that risk (Saunders, 1973; Kammerer, 1979; Allen, 1989).

The prophylactic effect of tocolytics remains unproven in these patients. If used, tocolytics should be administered with care. Monitor the patient carefully, and bear in mind the potential for pulmonary complications. Magnesium sulfate, beta-mimetics (eg, ritodrine, terbutaline), and indomethacin (if fetus is <32 wk gestation) can be used. Whenever using tocolytic agents, make certain that no contraindications to tocolysis, such as severe placental abruption, chorioamnionitis, or lethal anomalies, are present. If preterm delivery is likely, glucocorticoids can be administered to the mother to decrease the risk of neonatal complications. Avoid glucocorticoids if the mother is at serious risk for significant infection.

Delivery

Base delivery decisions on obstetric indications. The mode of delivery used should also be decided based on obstetric indications. If continuation of the pregnancy is expected to lead to maternal morbidity or mortality, delivery is indicated. If improvement of the maternal condition cannot be expected with delivery, treat the patient with the fetus in utero.

SPECIFIC CAUSES OF ACUTE ABDOMEN - APPENDICITIS

Section 3 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Incidence

Appendicitis is the most common nonobstetric cause of surgical emergency in pregnancy. The case-to-delivery ratio ranges from 1:2000 to 1:6000 (Gomez, 1979; Horowitz, 1985; Bailey, 1986; Sivanesaratnam, 2000). Pregnancy does not affect the overall incidence of appendicitis, but the severity may be increased in pregnancy. Appendicitis seems to be more common in the second trimester (Cunningham, 1975).

History and physical examination

Symptoms include the following:

• Abdominal pain is almost always present.
• • Pain is located in right lower quadrant in the first trimester.
  • In the second trimester, the appendix is located at the level of the umbilicus.
  • Pain is diffuse or in the right upper quadrant in the third trimester.
• Nausea is present in nearly all cases.
• Vomiting is present in two thirds of pregnant patients.
• Anorexia is present in only one third to two thirds of pregnant patients, while it is present almost universally in nonpregnant patients (Cunningham, 1975; Gomez, 1979; Bailey, 1986; Richards, 1989).

Signs include the following:

• Direct abdominal tenderness is observed most commonly and is only rarely absent (Cunningham, 1975; Babaknia, 1977).
• In the first trimester, tenderness is well localized in the right lower quadrant.
• Later in pregnancy, the tenderness is in the right periumbilical area, in the right upper quadrant, or is diffuse.
• Rebound tenderness is present in 55-75% of patients (Finch, 1974; Cunningham, 1975; Babaknia, 1977; Gomez, 1979; Bailey, 1986).
• Abdominal muscle rigidity is observed in 50-65% of patients (Brant, 1967; Finch, 1974; Gomez, 1979).
• The Rovsing sign (pain at the McBurney point when pressure is exerted over the descending colon) is observed as frequently in pregnant persons with appendicitis as in nonpregnant persons with appendicitis.
• Psoas irritation is observed less frequently during pregnancy compared to nonpregnant states (Richards, 1989).
• Rectal tenderness is usually present, particularly in the first trimester (Cunningham, 1975).
• Fever and tachycardia are variably present; they are not sensitive signs.

Workup

• White blood cell count: In pregnancy, the white blood cell count is often as high as 15,000/mm³. The wide reference range limits the usefulness of white blood cell counts during pregnancy (Bailey, 1986). Severe disease can occur with a normal count. Polymorphonuclear leukocytes are often greater than 80% when appendicitis is present.
• Urinalysis: Pyuria is observed in 10-20% of patients with appendicitis (Bailey, 1986). This may represent coincident asymptomatic bacteriuria.
• Ultrasound: In some centers, ultrasound has been used to help diagnose appendicitis.
• Upright abdominal radiograph: In severe disease, a right-sided mass or free air may be visualized.
• Both MRI scan and CT scan have been used in difficult cases.

Treatment

Treatment of appendicitis is surgical. Perform surgery as soon as the diagnosis is seriously considered. Either laparotomy or laparoscopy can be performed. Even if the appendix appears normal, there are 2 reasons to remove it: (1) early disease may be present despite its grossly normal appearance and (2) diagnostic confusion can be avoided if the condition recurs (Lau, 1986).

Most authorities suggest a right midtransverse incision directly over the point of maximal tenderness (McGee, 1989). Others suggest a lower abdominal midline incision to accommodate unexpected surgical findings and the possibility of the need for cesarean delivery (Cunningham, 1975).

Tailor the surgical approach to the clinical situation. Remember to tilt the operating table 30° to the patient's left to help bring the uterus away from the surgical site and to improve maternal venous return and cardiac output.

Prognosis

Perforation and abscess formation are more likely to occur in pregnant patients with appendicitis than in nonpregnant patients with appendicitis (Finch, 1974). Some researchers have reported increasing severity in the third trimester (Cunningham, 1975), while others have not (Babaknia, 1977; Bailey, 1986). Any increase in severity later in pregnancy may be due to a delay in diagnosis. The rate of generalized peritonitis relates directly to the interval of time from symptom onset to diagnosis (Bronstein, 1963). Maternal and fetal morbidity and mortality rates increase once perforation occurs (Babaknia, 1977).

SPECIFIC CAUSES OF ACUTE ABDOMEN – ACUTE CHOLECYSTITIS

Section 4 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Incidence

Estimates of occurrence of acute cholecystitis vary widely. The case-to-delivery ratio varies between 1:1130 and 1:12,890 (Hill, 1975; Landers, 1987). Asymptomatic gall bladder disease is more common, occurring in 3-4% of pregnant women. Chronic hemolytic conditions, such as sickle cell disease, increase the risk for gallstone formation.

History and physical examination

• Patients may have a history of previous episodes.
• Right upper quadrant pain is the most reliable symptom. Pain may radiate to the back.
• Vomiting occurs in approximately 50% of cases.
• Fever occurs in very few instances (Landers, 1987).
• Direct tenderness is usually present in the right upper quadrant. Rebound tenderness is rare.
• Cholecystitis can mimic appendicitis in the third trimester.

Workup

• Gallstones are present in more than 95% of patients with acute cholecystitis.
• Ultrasound is diagnostic and safe.
• If a radionucleotide scan of the gallbladder is needed, the radiation dose is not prohibitive.
• Blood tests are of limited value.
• Leukocytosis is observed in normal pregnancy.
• Serum alkaline phosphatase levels are normally elevated in pregnancy.
• Aspartate transferase and alanine transferase levels may help distinguish cholecystitis from hepatitis.
• Serum amylase levels are elevated transiently in up to a third of patients (Friley, 1972; Hiatt, 1986). A markedly elevated amylase level suggests pancreatitis.
• Serum electrolyte evaluations are needed if vomiting has been persistent.

Treatment

Initial treatment is supportive in nature.

• Intravenous fluids
• Nasogastric suction: This may be necessary if vomiting has been significant
• Analgesia: Demerol is preferred over morphine. Morphine may produce spasm of the sphincter of Oddi.
• If symptoms persist or if systemic or local signs are prominent, initiate broad-spectrum antibiotics (Friley, 1972; Hiatt, 1986).

If the patient does not tolerate supportive therapy or has recurrent bouts, surgery is indicated; a percutaneous drainage procedure may be indicated in select patients in order to defer definitive surgery (Friley, 1972; Hiatt, 1986). The timing of surgery for acute cholecystitis is controversial. Some researchers promote surgery during pregnancy to avoid recurrent episodes and hospitalization (Dixon, 1987); others promote delaying surgery until the postpartum period (Swisher, 1994). No prospective information is available. When a choice is available regarding the timing of surgery, operating in the second trimester minimizes fetal risk. A growing body of evidence supports the safety of laparoscopic cholecystectomy during pregnancy (Soper, 1992; Lanzafame, 1995).

Prognosis

Complications can occur, including empyema, perforation, pancreatitis, and failure to respond to medical management. With conservative management, 62-84% of patients can continue through delivery without surgery (Friley, 1972; Hiatt, 1986; Landers, 1987). In published series, perinatal outcome appears to be favorable if disease is uncomplicated or if surgery is performed in the second trimester (Friley, 1972; Hill, 1975; Hiatt, 1986; Dixon, 1987).

SPECIFIC CAUSES OF ACUTE ABDOMEN - PANCREATITIS

Section 5 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Incidence

Pancreatitis is an unusual and potentially devastating occurrence. The case-to-delivery ratio ranges from 1:1289 to 1:3333 (Corlett, 1972; Wilkinson, 1973; Jouppila, 1974; Ramin, 1995). The issue of whether pregnancy predisposes patients to pancreatitis is controversial (Corlett, 1972; Jouppila, 1974; DeVore, 1980; Block, 1989). Risk factors include the following:

• Cholelithiasis: This is the most common risk factor in pregnant patients with pancreatitis, observed in 90% of pregnancy-associated pancreatitis (Wilkinson, 1973; Kaiser, 1975; DeVore, 1980; McKay, 1980; Block, 1989; Ramin, 1995).
• Alcohol use
• Hyperlipidemia
• Hyperparathyroidism
• Abdominal trauma
• Viral infections

History and physical examination

• The presentation is similar to that of patients who are not pregnant.
• Acute abdominal pain is observed in 75% of cases (Wilkinson, 1973).
• Onset is usually sudden.
• Pain is located in the epigastrium.
• Nausea and vomiting are usually present and may be severe.
• Low-grade fever may be present.
• Jaundice is observed in a few patients.
• Epigastric tenderness is the most reliable physical finding.
• Peritoneal signs are minimal or absent.
• Bowel sounds are diminished.

Workup

• Serum amylase testing is the most useful test for diagnosis. During normal pregnancy, amylase levels are slightly elevated (Kaiser, 1975, Strickland, 1984). View such slight elevations with caution because they can occur with other disease entities (eg, intestinal perforation, infarction, intestinal obstruction).
• Other lab values may be helpful, including the following:
• • Hyperglycemia
  • Hyperbilirubinemia
  • Hypocalcemia
  • Hemoconcentration
  • Electrolyte abnormalities
• Ultrasound of the upper abdomen may be helpful for confirming gallbladder disease.

Treatment

Initial treatment is supportive.

• Provide intravenous fluids for hypovolemia.
• Correct electrolyte imbalances.
• Correct glucose levels.
• Correct calcium disturbances.
• Withhold oral intake.
• With severe disease, continuous nasogastric suctioning may be necessary.
• Total parenteral nutrition may be needed if disease is prolonged (Kirby, 1988).
• If gallbladder disease is causative, surgery can be performed when the patient's condition stabilizes.

Prognosis

Acute symptoms last for approximately 6 days (Block, 1989). The maternal mortality rate ranges from 0-37% (Corlett, 1972; Wilkinson, 1973; McKay, 1980; Block, 1989; Ramin, 1995), while the perinatal mortality rate is approximately 11% or less (Corlett, 1972; McKay, 1980; Block, 1989). The risk of perinatal death increases with the severity of disease.

SPECIFIC CAUSES OF ACUTE ABDOMEN - INTESTINAL OBSTRUCTION

Section 6 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Incidence

The case-to-delivery ratio ranges from 1:3600 to 1:5700 (Harer, 1962; Morris, 1965; Goldthorp, 1966). The frequency of this condition is increasing, due to a higher incidence of intra-abdominal surgery. Intestinal obstruction rarely occurs during the first trimester and occurs with equal frequency in the second and third trimester and puerperium.

Causes

Simple obstruction is the most common cause, most likely due to prior surgery and adhesions. Volvulus is the second most common etiology and is also predominantly due to adhesions. Both small intestinal and cecal or sigmoid volvulus have been reported in the absence of prior adhesions. Increased mobility of the bowel and displacement of the bowel into the upper abdomen by the growing uterus are implicated in these cases. Intussusception is less common, and incarcerated inguinal or femoral hernia and carcinoma are extremely rare.

History and physical examination

• Abdominal pain is observed in 90% of patients (Morris, 1965) and may be constant or periodic, mimicking labor. Pain may radiate to the flank, imitating pyelonephritis (Morris, 1965). The severity of pain may not reflect the severity of disease (Davis, 1983).
• Vomiting is a highly variable symptom. If the obstruction is more proximal, vomiting occurs earlier in the course. Severe obstruction can be present with no vomiting (Morris, 1965).
• Constipation is different from the usual constipation in pregnancy. Patients experience a complete cessation of stool and flatus.

Physical findings

• Classic distended tender abdomen with high-pitched bowel sounds is the exception in pregnancy.
• Abdominal tenderness may be absent (Davis, 1983).
• Pressure on the uterus often causes pain due to transmitted pressure to the bowel, misleading the clinician to consider a uterine process.
• Bowel sounds are often normal upon presentation.
• A tender cystic mass can sometimes be palpated (Pratt, 1981; Fanning, 1988).
• Rebound tenderness, fever, and tachycardia occur late in the course.

Workup

• Leukocytosis: Leukocytosis may be present. Remember that leukocytosis is also observed in normal pregnancy.
• Electrolyte abnormalities
• Hemoconcentration
• Elevated serum amylase levels
• Radiograph: An upright plain film of the abdomen is the best initial study. Do not avoid diagnostic radiography out of concern for fetal effects. This diagnosis is difficult to make without the use of radiography. Sequential films may be needed (Davis, 1983).

Treatment

Treatment is surgical, the same as for patients who are not pregnant. Clinical management includes the following:

• Correct fluid and electrolyte imbalances.
• Perform decompression of the bowel.
• Help relieve the obstruction.
• Resect nonviable tissue.
• Fluid management is critical during pregnancy because uterine blood flow depends on normal maternal blood volume
• A midline abdominal incision is optimal.

Prognosis

Intestinal obstruction is a serious complication in pregnancy, with maternal mortality rates ranging from 10-20%. Perinatal mortality rates range from 20-30% (Harer, 1958; Goldthorp, 1966; Beck, 1979).

Specific causes of acute abdomen – Rare causes encountered during pregnancy

• Mesenteric venous thrombosis
• • This is an extremely rare but potentially lethal event. The exact incidence is not known. Most reported cases have occurred in settings where dehydration (eg, from hyperemesis gravidarum) complicated an underlying hypercoagulable state (eg, factor V Leiden).
  • The treatment is resection of the involved segment with institution of chronic anticoagulation. The surgeon needs to have a low threshold for reoperation, as extension of the process to adjacent areas of the bowel is common.
• Rupture of visceral artery aneurysm
• • Any of the visceral vessels may become aneurysmal, but splenic artery aneurysms are probably the most common and the most apt to rupture during the puerperium. Only scattered case reports are to be found in the literature.
  • The treatment is emergency splenectomy. Because of the lethality of this complication, elective aneurysm resection or angiographic coiling is recommended when these lesions are noted in women of child-bearing age.

SPECIFIC CAUSES OF ACUTE ABDOMEN – UROLITHIASIS

Section 7 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Incidence

The case-to-delivery ratio is approximately 1:1600 (Strong, 1978; Beck, 1979).

History and physical examination

• Pain, usually in the flank - Almost always the presenting complaint
• Nausea and vomiting
• Dysuria
• Urgency
• Fever
• Gross hematuria
• Possible history of a prior episode in 25% (Strong, 1978; Beck, 1979)
• Costovertebral angle tenderness - Almost always present
• Abdominal tenderness - May be observed

Workup

• Patients may have coexisting urinary tract infection.
• Microscopic hematuria is observed in 75% of cases. The absence of hematuria does not exclude a stone.
• Strain urine in search of a stone.
• Perform an ultrasound on the urinary tract to check for evidence of obstruction.
• Remember the physiologic dilatation of the right side in the second half of pregnancy.

Treatment

Treatment depends on the size and location of the stone, the degree of obstruction, the severity of symptoms, and the presence of infection. Most stones pass with hydration. Minimally invasive procedures can be considered, including ureteral stent placement, ureteroscopic retrieval, and percutaneous nephrostomy. Extracorporeal shock-wave lithotripsy has not been approved for use in pregnancy.

Prognosis

A good perinatal outcome is expected, unless a severe infection is present.

For excellent patient education resources, visit eMedicine's Pregnancy and Reproduction Center and Kidneys and Urinary System Center. Also, see eMedicine's patient education articles Ectopic Pregnancy and Blood in the Urine.

GYNECOLOGIC CAUSES OF ACUTE ABDOMEN IN PREGNANCY

Section 8 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Rupture of ovarian cyst

Incidence

Ovarian cysts occur in pregnancy with a frequency ranging from 1 in 81 to 1 in 1000 (Booth, 1963; Eastman, 1966; Ballard, 1984; Hopkins, 1986). Rupture of ovarian cysts is rare.

History and physical examination

• Patients may have a history of mild trauma, such as caused by a fall, intercourse, or a vaginal examination.
• Rupture may occur spontaneously.
• The patient may have mild chronic lower abdominal discomfort that suddenly intensifies.
• Upon physical examination, the lower abdomen may demonstrate peritoneal signs, and tenderness and guarding may be present.

Workup

• The hemoglobin level may drop.
• Ultrasound can help detect the presence of fluid in the cul-de-sac.

Treatment

• Treatment is surgical.
• Conserve as much ovarian tissue as possible.

Prognosis

In the absence of malignancy, the prognosis is excellent (Chamberlain, 1969).

Adnexal torsion

Incidence

Adnexal torsion is unusual and occurs predominantly in teenagers and young women. Pregnancy predisposes to adnexal torsion, with 1 in 5 adnexal torsions occurring during pregnancy (Hibbard, 1985). The condition is associated with an ovarian mass in 50-60% of patients, and the mass is most often a dermoid. Adnexal torsion occurs more frequently on the right than on the left, by a ratio of 3:2. It occurs most frequently in the first trimester, occasionally in the second, and rarely in the third (Hibbard, 1985).

History and physical examination

• Patients present with acute, severe, colicky, unilateral, lower abdominal and pelvic pain.
• Two thirds of patients also have nausea and vomiting (Lomano, 1970; Mashiach, 1990).
• Patients may provide a history of prior intermittent episodes of similar pain.
• A low-grade fever can occur.
• A tender adnexal mass is palpated in 90% of patients with adnexal torsion.

Workup

• If adnexal necrosis has occurred, leukocytosis and fever can occur. Leukocytosis is also observed in normal pregnancy.
• Ultrasound can be useful for documenting the presence of an ovarian cyst.
• Color Doppler findings can possibly help document absent ovarian flow in the central ovarian parenchyma (Fleischer, 1995).
• If the diagnosis is uncertain, diagnostic laparoscopy can be used.

Treatment

Treatment is surgical, with preservation of as much ovarian tissue as possible (Chamberlain, 1969). If the tissue is necrotic, removal is warranted and unilateral salpingo-oophorectomy is appropriate. If a partial torsion is confirmed, conservative management is appropriate. Untwist the pedicle, remove the cyst, and stabilize the ovary. If removal of the corpus luteum is necessary prior to 10 weeks of gestation, progesterone supplementation is warranted.

Prognosis

Pregnancy outcome associated with adnexal torsion generally is good (Mashiach, 1990).

Degenerating myoma

Incidence

Red degeneration occurs in 5-10% of pregnant women with myomas. Degenerating myoma often occurs between 12 and 20 weeks' gestation.

History and physical examination

• Patients present with an acute onset of significant localized abdominal pain.
• They may experience vomiting and tenderness over a mass in the uterus.
• Patients may experience a low-grade fever (Chamberlain, 1969).

Workup

Ultrasound is helpful when used directly over the area of pain. A degenerating myoma has a mixed echodense or echolucent appearance.

Treatment

During pregnancy, treatment is medical in nature because red degeneration is a self-limited process. Treatment includes analgesia with narcotic or anti-inflammatory agents. If narcotics are ineffective, a short course of indomethacin can provide effective pain relief. Because indomethacin has fetal effects, including oligohydramnios and partial constriction of the fetal ductus arteriosis, its use is limited to less than 32 weeks. Patients should be monitored closely.

Prognosis

Pregnancy outcome associated with red degeneration usually is good.

OBSTETRIC CAUSES OF ACUTE ABDOMEN

Section 9 of 10  

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

Placental abruption

Incidence

Incidence of placental abruption varies depending on the population. Generally, abruption occurs in 1 in 150 deliveries, but the rate ranges from 1 in 75 to 1 in 225 deliveries (Hurd, 1983; Karegard, 1986). Risk increases with (1) hypertension, (2) preterm premature rupture of the membranes, (3) cocaine abuse, (4) cigarette smoking, and (5) uterine myoma.

History and physical examination

Symptoms include the following:

• Vaginal bleeding (78%)
• Uterine tenderness and back pain (66%)
• Uterine contractions (22%)

Signs include the following (Hurd, 1983):

• Fundal tenderness
• High frequency of contractions or hypertonus (34%)
• Nonreassuring fetal heart rate (60%)
• Intrauterine fetal demise (15%)
• In advanced cases, shock, evidence of disseminated intravascular coagulation, or renal failure possible

Workup

• Monitor the fetus for signs of distress.
• Monitor contractions for evidence of hypertonus.
• Obtain a complete blood cell count, coagulation profile, and type and screen.
• Perform the Kleihauer-Betke test.
• Ultrasound can be performed, but, at most, only 25% of placental abruptions are detected.

Treatment

At term, delivery is treatment. The mode of delivery depends on obstetrical indications. When remote from term and if the abruption is mild, conservative management can be attempted with intravenous fluid, tocolytics, bed rest, steroids, and continuous fetal monitoring.

Prognosis

Maternal morbidity depends on the presence of consumptive coagulopathy, shock, and renal failure. Perinatal mortality rates range from 20-35%.

Uterine rupture

Incidence

The frequency of uterine rupture varies widely among different institutions. The case-to-delivery ratio ranges from 1 in 1235 to 1 in 3000 (Rachagan, 1991; Miller, 1996).

History and physical examination

Symptoms include the following:

• Severe abdominal pain
• Chest pain from hemoperitoneum

Signs include the following:

• Nonreassuring fetal heart rate pattern, severe bradycardia (most common sign)
• Loss of station of presenting part
• Vaginal bleeding
• Hypovolemia
• Possible history of prior uterine surgery or uterine anomaly

Workup

• Diagnosis is clinical.
• Ultrasound may be useful if immediately available.

Treatment

Treatment consists of immediate cesarean delivery with probable hysterectomy. Repair of the uterus may be possible in select cases. Blood products may be needed.

Prognosis

The maternal mortality rate reportedly is as high as 44% in Zambia (Nkata, 1996). Prompt diagnosis and surgery, large amounts of blood products, and antibiotics improve maternal outcome. Fetal mortality rates range from 50-75% (Rachagan, 1991; Eden, 1986).

Hepatic rupture

Incidence

The case-to-delivery ratio is 1:45,000 (Smith, 1991). Hepatic rupture may be spontaneous. Most are associated with preeclampsia and eclampsia (Hunter, 1995). HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets) is often present.

History and physical examination

• Right upper quadrant pain and tenderness
• Possible history of pregnancy-induced hypertension
• Hemorrhagic shock
• Distended abdomen

Workup

Diagnosis can be confirmed based on CT scan findings.

Treatment

• Correct any associated coagulopathy. Recombinant factor VIIa has been used to achieve hemostasis and to avert operative management (Merchant, 2004; Dart, 2004).
• Most patients have been treated operatively, but there is an increasing trend toward nonoperative management (which is consistent with the current principles of liver trauma management in the nonpregnant patient). In surgery, do as follows:
• • Repair the liver laceration, if possible.
  • Use packing.
  • Remember that hepatic artery ligation and resection may be needed but can almost always be avoided.

Prognosis

Maternal mortality rates range from 20-75% (Smith, 1991).

Ruptured ectopic pregnancy

Incidence

Ruptured ectopic pregnancy occurs in more than 1 in 100 pregnancies in the United States.

History and physical examination

• Pain (abdominal or pelvic) is the most frequent symptom, occurring in 95% of patients.
• Amenorrhea with abnormal uterine bleeding is observed in 60-80% of patients.
• Gastrointestinal symptoms are present in 80% of patients.
• Dizziness or syncope occurs in 58% of patients (Dorfman, 1984).
• Hypovolemia is a possible finding.
• Patients may have a pelvic mass.

Workup

• Perform a complete blood cell count, quantitative human chorionic gonadotropin (hCG) evaluation, and type and screen.
• Ultrasound is helpful.
• If the beta-hCG level is more than 6000 mIU/mL, the gestational sac should be visible in the uterus with an abdominal probe.
• If the beta-hCG level is 1000-2000 mIU/mL, a gestational sac should be seen in the uterus with a vaginal probe.

Treatment

Treatment is surgical, with laparoscopy or laparotomy. Linear salpingotomy, linear salpingostomy, or salpingectomy can be performed. Blood products may be needed.

Prognosis

The maternal mortality rate is 3.8 cases per 10,000 population (Goldner, 1993), which is 10 times greater than for vaginal delivery and 50 times greater than for induced abortion (Dorfman, 1983).

REFERENCES

Section 10 of 10

• Authors and Editors
• General Principles
• Specific Causes Of Acute Abdomen - Appendicitis
• Specific Causes Of Acute Abdomen – Acute Cholecystitis
• Specific Causes Of Acute Abdomen - Pancreatitis
• Specific Causes Of Acute Abdomen - Intestinal Obstruction
• Specific Causes Of Acute Abdomen – Urolithiasis
• Gynecologic Causes Of Acute Abdomen In Pregnancy
• Obstetric Causes Of Acute Abdomen
• References

• Aboutanos SZ, Aboutanos MB, Malhotra AK, et al. Management of a pregnant patient with an open abdomen. J Trauma. Nov 2005;59(5):1052-6.
• Al Asfar F, Saber M, Dhar PM, Al Awadhi N. Rupture of splenic artery aneurysm during labor: a case report of maternal and fetal survival. Med Princ Pract. Jan-Feb 2005;14(1):53-4.
• Allen JR, Helling TS, Langenfeld M. Intraabdominal surgery during pregnancy. Am J Surg. Dec 1989;158(6):567-9. [Medline].
• Allmendinger N, Hallisey MJ, Ohki SK, Straub J. Percutaneous cholecystostomy treatment of acute cholecystitis in pregnancy. Obstet Gynecol. Oct 1995;86(4 Pt 2):653-4. [Medline].
• Alshawi JS. Recurrent sigmoid volvulus in pregnancy: report of a case and review of the literature. Dis Colon Rectum. Sep 2005;48(9):1811-3.
• American College of Obstetricians and Gynecologists. Guidelines for diagnostic imaging during pregnancy. ACOG Committee Opinion 158. Washington, DC:. ACOG;1995.
• Babaknia A, Parsa H, Woodruff JD. Appendicitis during pregnancy. Obstet Gynecol. Jul 1977;50(1):40-4. [Medline].
• Baer JL, Feis RA, Arens RA. Appendicitis in pregnancy with changes in position and axis of the normal appendix in pregnancy. JAMA. 1932;98:1359-64.
• Bailey LE, Finley RK Jr, Miller SF, Jones LM. Acute appendicitis during pregnancy. Am Surg. Apr 1986;52(4):218-21. [Medline].
• Ballard CA. Ovarian tumors associated with pregnancy termination patients. Am J Obstet Gynecol. Jun 15 1984;149(4):384-7. [Medline].
• Banas T, Klimek M, Fugiel A, Skotniczny K. Spontaneous uterine rupture at 35 weeks'' gestation, 3 years after laparoscopic myomectomy, without signs of fetal distress. J Obstet Gynaecol Res. Dec 2005;31(6):527-30.
• Baykal C, Al A, Ozer S, et al. Ileal resection for gangrenous ileal volvulus in a term pregnancy: a case report. Arch Gynecol Obstet. Feb 2006;273(5):304-6.
• Beck WW Jr. Intestinal obstruction in pregnancy. Obstet Gynecol. Mar 1974;43(3):374-8. [Medline].
• Bettendorf O, Falbrede J, Eltze E, Bocker W. Ruptured splenic artery aneurysm during pregnancy with maternal death and premature infant survival. Eur J Obstet Gynecol Reprod Biol. Nov 10 2004;117(1):119-20.
• Birchard KR, Brown MA, Hyslop WB, et al. MRI of acute abdominal and pelvic pain in pregnant patients. AJR Am J Roentgenol. Feb 2005;184(2):452-8.
• Block P, Kelly TR. Management of gallstone pancreatitis during pregnancy and the postpartum period. Surg Gynecol Obstet. May 1989;168(5):426-8. [Medline].
• Blum A, Tatour I, Monir M, et al. Gallstones in pregnancy and their complications: postpartum acute pancreatitis and acute peritonitis. Eur J Intern Med. Nov 2005;16(7):473-6.
• Booth RT. Ovarian tumors in pregnancy. Obstet Gynecol. 1963;21:189.
• Brant HA. Acute appendicitis in pregnancy. Obstet Gynecol. Jan 1967;29(1):130-8. [Medline].
• Brewer H, Gefroh S, Munkarah A, et al. Asymptomatic uterine rupture of a cornual pregnancy in the third trimester: a case report. J Reprod Med. Sep 2005;50(9):715-8. [Medline].
• Bronstein E, Friedman M. Acute appendicitis in pregnancy. Am J Obstet Gynecol. 1963;86:514-6.
• Cappell MS. The fetal safety and clinical efficacy of gastrointestinal endoscopy during pregnancy. Gastroenterol Clin North Am. Mar 2003;32(1):123-79. [Medline].
• Carlson KL, Bader CL. Ruptured subcapsular liver hematoma in pregnancy: a case report of nonsurgical management. Am J Obstet Gynecol. Feb 2004;190(2):558-60.
• Carver TW, Antevil J, Egan JC, Brown CV. Appendectomy during early pregnancy: what is the preferred surgical approach?. Am Surg. Oct 2005;71(10):809-12. [Medline].
• Chamberlain G. Gynaecological aspects of the acute abdomen. Ann R Coll Surg Engl. Sep 1969;45(3):174-85. [Medline].
• Chen CP, Wang KG, Su TH, Yang YC. Acute pancreatitis in pregnancy. Acta Obstet Gynecol Scand. Sep 1995;74(8):607-10. [Medline].
• Corlett RC Jr, Mishell DR Jr. Pancreatitis in pregnancy. Am J Obstet Gynecol. Jun 1 1972;113(3):281-90. [Medline].
• Cunningham FG, McCubbin JH. Appendicitis complicating pregnancy. Obstet Gynecol. Apr 1975;45(4):415-20. [Medline].
• Dart BW, Cockerham WT, Torres C, et al. A novel use of recombinant factor VIIa in HELLP syndrome associated with spontaneous hepatic rupture and abdominal compartment syndrome. J Trauma. Jul 2004;57(1):171-4.
• Davis MR, Bohon CJ. Intestinal obstruction in pregnancy. Clin Obstet Gynecol. Dec 1983;26(4):832-42. [Medline].
• DeVore GR. Acute abdominal pain in the pregnant patient due to pancreatitis, acute appendicitis, cholecystitis, or peptic ulcer disease. Clin Perinatol. Sep 1980;7(2):349-69. [Medline].
• Dixon NP, Faddis DM, Silberman H. Aggressive management of cholecystitis during pregnancy. Am J Surg. Sep 1987;154(3):292-4. [Medline].
• Dorfman SF, Grimes DA, Cates W Jr, et al. Ectopic pregnancy mortality, United States, 1979 to 1980: clinical aspects. Obstet Gynecol. Sep 1984;64(3):386-90. [Medline].
• Dorfman SF. Deaths from ectopic pregnancy, United States, 1979 to 1980. Obstet Gynecol. Sep 1983;62(3):334-8. [Medline].
• Eastman NJ, Hallman LM. Ovarian tumors in pregnancy. In: Eastman NJ, Hellman LM, eds. Williams Obstetrics. 13th ed. New York, NY: Appleton-Century-Crofts; 1966.
• Eden RD, Parker RT, Gall SA. Rupture of the pregnant uterus: a 53-year review. Obstet Gynecol. Nov 1986;68(5):671-4. [Medline].
• Eyvazzadeh AD, Pedrosa I, Rofsky NM, et al. MRI of right-sided abdominal pain in pregnancy. AJR Am J Roentgenol. Oct 2004;183(4):907-14.
• Fanning J, Cross CB. Post-cesarean section cecal volvulus. Am J Obstet Gynecol. May 1988;158(5):1200-2. [Medline].
• Finch DR, Lee E. Acute appendicitis complicating pregnancy in the Oxford region. Br J Surg. Feb 1974;61(2):129-32. [Medline].
• Fleischer AC, Stein SM, Cullinan JA, Warner M. Color Doppler sonography of adnexal torsion. J Ultrasound Med. Jul 1995;14(7):523-8. [Medline].
• Friley MD, Douglas G. Acute cholecystitis in pregnancy and the puerperium. Am Surg. Jun 1972;38(6):314-7. [Medline].
• Gadacz TR, Talamini MA. Traditional versus laparoscopic cholecystectomy. Am J Surg. Mar 1991;161(3):336-8. [Medline].
• Garden AS, Griffiths RD, Weindling AM, Martin PA. Fast-scan magnetic resonance imaging in fetal visualization. Am J Obstet Gynecol. May 1991;164(5 Pt 1):1190-6. [Medline].
• Goldner TE, Lawson HW, Xia Z, Atrash HK. Surveillance for ectopic pregnancy--United States, 1970-1989. Mor Mortal Wkly Rep CDC Surveill Summ. Dec 17 1993;42(6):73-85. [Medline].
• Goldthorp WO. Intestinal obstruction during pregnancy and the puerperium. Br J Clin Pract. Jul 1966;20(7):367-76. [Medline].
• Gomez A, Wood M. Acute appendicitis during pregnancy. Am J Surg. Feb 1979;137(2):180-3. [Medline].
• Gurbuz AT, Peetz ME. The acute abdomen in the pregnant patient. Is there a role for laparoscopy?. Surg Endosc. Feb 1997;11(2):98-102. [Medline].
• Harer W. Intestinal obstruction associated with pregnancy. Obstet Gynecol. 1962;19:11-5.
• Harer W. Volvulus complicating pregnancy and pueperium. Obstet Gynecol. 1958;12:399-406.
• Harris BM, Kuczkowski KM. Diagnostic dilemma: hepatic rupture due to HELLP syndrome vs. trauma. Arch Gynecol Obstet. Jul 2005;272(2):176-8.
• Harvey EB, Boice JD Jr, Honeyman M, Flannery JT. Prenatal x-ray exposure and childhood cancer in twins. N Engl J Med. Feb 28 1985;312(9):541-5. [Medline].
• Hiatt JR, Hiatt JC, Williams RA, Klein SR. Biliary disease in pregnancy: strategy for surgical management. Am J Surg. Feb 1986;151(2):263-5. [Medline].
• Hibbard LT. Adnexal torsion. Am J Obstet Gynecol. Jun 15 1985;152(4):456-61. [Medline].
• Hieronimus S, Benlian P, Bayer P, et al. Combination of apolipoprotein E2 and lipoprotein lipase heterozygosity causes severe hypertriglyceridemia during pregnancy. Diabetes Metab. Jun 2005;31(3 Pt 1):295-7.
• Hill LM, Johnson CE, Lee RA. Cholecystectomy in pregnancy. Obstet Gynecol. Sep 1975;46(3):291-3. [Medline].
• Hill LM, Symmonds RE. Small bowel obstruction in pregnancy. A review and report of four cases. Obstet Gynecol. Feb 1977;49(2):170-3. [Medline].
• Hopkins MP, Duchon MA. Adnexal surgery in pregnancy. J Reprod Med. Nov 1986;31(11):1035-7. [Medline].
• Horowitz MD, Gomez GA, Santiesteban R, Burkett G. Acute appendicitis during pregnancy. Diagnosis and management. Arch Surg. Dec 1985;120(12):1362-7. [Medline].
• Huang JC, Shin JS, Huang YT, et al. Small bowel volvulus among adults. J Gastroenterol Hepatol. Dec 2005;20(12):1906-12.
• Hunter SK, Martin M, Benda JA, Zlatnik FJ. Liver transplant after massive spontaneous hepatic rupture in pregnancy complicated by preeclampsia. Obstet Gynecol. May 1995;85(5 Pt 2):819-22. [Medline].
• Hurd WW, Miodovnik M, Hertzberg V, Lavin JP. Selective management of abruptio placentae: a prospective study. Obstet Gynecol. Apr 1983;61(4):467-73. [Medline].
• Hurwitz LM, Yoshizumi T, Reiman RE, et al. Radiation dose to the fetus from body MDCT during early gestation. AJR Am J Roentgenol. Mar 2006;186(3):871-6.
• Jones WA, Correa RJ Jr, Ansell JS. Urolithiasis associated with pregnancy. J Urol. Sep 1979;122(3):333-5. [Medline].
• Jouppila P, Mokka R, Larmi TK. Acute pancreatitis in pregnancy. Surg Gynecol Obstet. Dec 1974;139(6):879-82. [Medline].
• Kaiser R, Berk JE, Fridhandler L. Serum amylase changes during pregnancy. Am J Obstet Gynecol. Jun 1 1975;122(3):283-6. [Medline].
• Kalu E, Sherriff E, Alsibai MA, Haidar M. Gestational intestinal obstruction: a case report and review of literature. Arch Gynecol Obstet. Apr 2006;274(1):60-2.
• Kammerer WS. Nonobstetric surgery during pregnancy. Med Clin North Am. Nov 1979;63(6):1157-64. [Medline].
• Karegard M, Gennser G. Incidence and recurrence rate of abruptio placentae in Sweden. Obstet Gynecol. Apr 1986;67(4):523-8. [Medline].
• Kirby DF, Fiorenza V, Craig RM. Intravenous nutritional support during pregnancy. JPEN J Parenter Enteral Nutr. Jan-Feb 1988;12(1):72-80. [Medline].
• Kleiss K, Choy-Hee L, Fogle R, Lindsay M. Torsion of the gallbladder in pregnancy. A case report. J Reprod Med. Mar 2003;48(3):206-8. [Medline].
• Ko C. Biliary sludge and acute pancreatitis during pregnancy. Nat Clin Pract Gastroenterol Hepatol. Jan 2006;3(1):53-7; quiz following 57.
• Ko CW, Beresford SA, Schulte SJ, et al. Incidence, natural history, and risk factors for biliary sludge and stones during pregnancy. Hepatology. Feb 2005;41(2):359-65.
• Landers D, Carmona R, Crombleholme W, Lim R. Acute cholecystitis in pregnancy. Obstet Gynecol. Jan 1987;69(1):131-3. [Medline].
• Lanzafame RJ. Laparoscopic cholecystectomy during pregnancy. Surgery. Oct 1995;118(4):627-31; discussion 631-3. [Medline].
• Lau WY, Fan ST, Yiu TF, et al. The clinical significance of routine histopathologic study of the resected appendix and safety of appendiceal inversion. Surg Gynecol Obstet. Mar 1986;162(3):256-8. [Medline].
• Lim HK, Bae SH, Seo GS. Diagnosis of acute appendicitis in pregnant women: value of sonography. AJR Am J Roentgenol. Sep 1992;159(3):539-42. [Medline].
• Lomano JM, Trelford JD, Ullery JC. Torsion of the uterine adnexa causing an acute abdomen. Obstet Gynecol. Feb 1970;35(2):221-5. [Medline].
• Malet P, Soloway R. Diseases of the gallbladder and bile ducts. In: Wyngaarden J, Smith LJ, eds. Cecil Textbook of Medicine. 18th ed. Philadelphia, Pa: WB Saunders; 1988:. 859-72.
• Mashiach S, Bider D, Moran O, et al. Adnexal torsion of hyperstimulated ovaries in pregnancies after gonadotropin therapy. Fertil Steril. Jan 1990;53(1):76-80. [Medline].
• Mazze RI, Kallen B. Reproductive outcome after anesthesia and operation during pregnancy: a registry study of 5405 cases. Am J Obstet Gynecol. Nov 1989;161(5):1178-85. [Medline].
• McGee TM. Acute appendicitis in pregnancy. Aust N Z J Obstet Gynaecol. Nov 1989;29(4):378-85. [Medline].
• McKay AJ, O''Neill J, Imrie CW. Pancreatitis, pregnancy and gallstones. Br J Obstet Gynaecol. Jan 1980;87(1):47-50. [Medline].
• Merchant SH, Mathew P, Vanderjagt TJ, et al. Recombinant factor VIIa in management of spontaneous subcapsular liver hematoma associated with pregnancy. Obstet Gynecol. May 2004;103(5 Pt 2):1055-8.
• Miller DA, Paul RH. Rupture of the unscarred uterus. Am J Obstet Gynecol. 1996;174:345.
• Morris E. Intestinal obstruction associated with pregnancy. J Obstet Gynaecol Br Commonw. 1965;72:36-44.
• Nkata M. Rupture of the uterus: a review of 32 cases in a general hospital in Zambia. BMJ. May 11 1996;312(7040):1204-5. [Medline].
• Pedrosa I, Levine D, Eyvazzadeh AD, et al. MR imaging evaluation of acute appendicitis in pregnancy. Radiology. Mar 2006;238(3):891-9.
• Pratt AT, Donaldson RC, Evertson LR, Yon JL Jr. Cecal volvulus in pregnancy. Obstet Gynecol. Jun 1981;57(6 Suppl):37S-40S. [Medline].
• Pritchard JA, Baldwin RM, Dickey JC, et al. Blood volume changes in pregnancy and the puerperium, II: red blood cell loss and changes in apparent blood volume during and following vaginal delivery, cesarean section, and cesarean section plus total hysterectomy. Am J Obstet Gynecol. 1962;84:1271.
• Puylaert JB, Rutgers PH, Lalisang RI, et al. A prospective study of ultrasonography in the diagnosis of appendicitis. N Engl J Med. Sep 10 1987;317(11):666-9. [Medline].
• Rachagan SP, Raman S, Balasundram G, Balakrishnan S. Rupture of the pregnant uterus--a 21-year review. Aust N Z J Obstet Gynaecol. Feb 1991;31(1):37-40. [Medline].
• Ramin KD, Ramin SM, Richey SD, Cunningham FG. Acute pancreatitis in pregnancy. Am J Obstet Gynecol. Jul 1995;173(1):187-91. [Medline].
• Richards C, Daya S. Diagnosis of acute appendicitis in pregnancy. Can J Surg. Sep 1989;32(5):358-60. [Medline].
• Richardson AJ, Bahlool S, Knight J. Ruptured splenic artery aneurysm in pregnancy presenting in a manner similar to pulmonary embolus. Anaesthesia. Feb 2006;61(2):187-9.
• Rizzo AG. Laparoscopic surgery in pregnancy: long-term follow-up. J Laparoendosc Adv Surg Tech A. Feb 2003;13(1):11-5.
• Saunders P, Milton PJ. Laparotomy during pregnancy: an assessment of diagnostic accuracy and fetal wastage. Br Med J. Jul 21 1973;3(872):165-7. [Medline].
• Shaw C, Fattah N, Lynch D, Stokes M. Spontaneous rupture of the liver following a normal pregnancy and delivery. Ir Med J. Jan 2005;98(1):27-8.
• Simmons DC, Tarnasky PR, Rivera-Alsina ME, et al. Endoscopic retrograde cholangiopancreatography (ERCP) in pregnancy without the use of radiation. Am J Obstet Gynecol. May 2004;190(5):1467-9.
• Sivanesaratnam V. The acute abdomen and the obstetrician. Baillieres Best Pract Res Clin Obstet Gynaecol. Feb 2000;14(1):89-102. [Medline].
• Smith LG Jr, Moise KJ Jr, Dildy GA 3rd, Carpenter RJ Jr. Spontaneous rupture of liver during pregnancy: current therapy. Obstet Gynecol. Feb 1991;77(2):171-5. [Medline].
• Sonmezer M, Aytac R, Demirel LC, Kurtay G. Mesenteric vein thrombosis in a pregnant patient heterozygous for the factor V (1691 G --> A) Leiden mutation. Eur J Obstet Gynecol Reprod Biol. Jun 15 2004;114(2):234-5.
• Soper NJ, Hunter JG, Petrie RH. Laparoscopic cholecystectomy during pregnancy. Surg Endosc. May-Jun 1992;6(3):115-7. [Medline].
• Stelken AM, Younis LT, Jennison SH, et al. Prognostic value of cardiopulmonary exercise testing using percent achieved of predicted peak oxygen uptake for patients with ischemic and dilated cardiomyopathy. J Am Coll Cardiol. Feb 1996;27(2):345-52. [Medline].
• Strickland DM, Hauth JC, Widish J, et al. Amylase and isoamylase activities in serum of pregnant women. Obstet Gynecol. Mar 1984;63(3):389-91. [Medline].
• Strong DW, Murchison RJ, Lynch DF. The management of ureteral calculi during pregnancy. Surg Gynecol Obstet. Apr 1978;146(4):604-8. [Medline].
• Swisher SG, Schmit PJ, Hunt KK, et al. Biliary disease during pregnancy. Am J Surg. Dec 1994;168(6):576-9; discussion 580-1. [Medline].
• Wilkinson EJ. Acute pancreatitis in pregnancy: a review of 98 cases and a report of 8 new cases. Obstet Gynecol Surv. May 1973;28(5):281-303. [Medline].
• Wu JM, Chen KH, Lin HF, et al. Laparoscopic appendectomy in pregnancy. J Laparoendosc Adv Surg Tech A. Oct 2005;15(5):447-50.
• Yagmurdur MC, Agalar F, Daphan CE. Spontaneous hepatic rupture in pregnancy. Eur J Emerg Med. Mar 2000;7(1):75-6. [Medline].
• Yilmazer M, Kurtay G, Sonmezer M, Akar N. Factor V Leiden and prothrombin 20210 G-A mutations in controls and in patients with thromboembolic events during pregnancy or the puerperium. Arch Gynecol Obstet. Oct 2003;268(4):304-8.