AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

An abortion is the spontaneous or induced loss of early pregnancy. Early pregnancy is considered any pregnancy less than 20 weeks of gestation, defined by the inability of the fetus to survive outside of the uterus. The term miscarriage is often used to denote spontaneous abortion.

Pathophysiology

A spontaneous abortion is a process that can be divided into 4 stages, as follows: threatened, inevitable, incomplete, and complete.

• Threatened abortion: Vaginal bleeding of any degree during early pregnancy is considered to represent a threatened abortion, although such bleeding is very common. Approximately a fourth of all pregnant women have some degree of vaginal bleeding during the first 2 trimesters. About half of these cases progress to an actual miscarriage. Bleeding and pain accompanying threatened abortion usually are not very intense. Threatened abortion rarely presents with severe vaginal bleeding. On vaginal examination, the cervical os is closed, and no cervical motion tenderness or tissue is found. Diffuse uterine tenderness and/or adnexal tenderness may be present. Threatened abortion is defined by the absence of passing/passed tissue and the presence of a closed cervix. These findings differentiate threatened abortion from later stages of abortion.
• Inevitable abortion: Vaginal bleeding is accompanied by dilatation of the cervical canal. Bleeding usually is more severe than with threatened abortion and often is associated with abdominal pain.
• Incomplete abortion: Vaginal bleeding usually is intense and accompanied by abdominal pain. The cervical os is open and products of conception are being passed (confirmed by either patient report or evidence upon examination). Ultrasonography reveals that some products of conception still are present in the uterus.
• Complete abortion: Patients usually present with a history of bleeding, abdominal pain, and tissue passage. By the time miscarriage is complete, bleeding and pain usually have subsided. Diagnosis may be confirmed by observation of the aborted fetus with the complete placenta. Ultrasound reveals a vacant uterus.

Frequency

United States

Approximately 5-15% of diagnosed pregnancies result in spontaneous abortion.

International

Some European investigators quote the rate of spontaneous abortion to be as low as 2-5%.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• Patients with spontaneous abortion usually present to the ED with vaginal bleeding and/or abdominal pain.
• • Vaginal bleeding may vary from slight spotting to a severe life-threatening hemorrhage. Quantification of the amount of bleeding is very important. The patient's history should reflect the number of pads or tampons used.
  • Presence of blood clots or tissue may be an important sign indicating progression of spontaneous abortion.
  • Abdominal pain usually is located in one or both lower quadrants.
  • Suprapubic pain is common.
  • Pain may radiate to the lower back, buttocks, genitalia, and perineum.
• Other symptoms, such as fever or chills, are more characteristic of a septic abortion.
• Consider any woman of childbearing age with vaginal bleeding pregnant until proven otherwise.

Physical

Immediately evaluate patients who are experiencing hemodynamic instability or severe vaginal bleeding, including orthostatic vital signs and abdominal and pelvic examinations. Initiate emergency fluid resuscitation in cases of orthostatic hypotension.

• Pelvic examination should focus on determining the source of bleeding.
• • Blood from cervical os
  • Intensity of bleeding
  • Presence of clots or tissue fragments
  • Cervical motion tenderness (presence increases suspicion for ectopic pregnancy)
  • State of cervical os: open indicates inevitable or incomplete abortion; closed indicates threatened abortion.
  • Uterine size and tenderness, as well as adnexal tenderness or masses

Causes

• Embryonic abnormalities account for 80-90% of first-trimester miscarriages.
• • Chromosomal abnormalities are the most common cause of spontaneous abortion.
  • More than 90% of cytogenic and morphologic errors are eliminated through spontaneous abortion.
  • Chromosomal abnormalities have been found in more than 75% of fetuses aborted in the first trimester.
  • The rate of chromosomal abnormalities increases with age, with a steep increase in women older than 35 years.
• Maternal factors account for the majority of second-trimester abortions. These factors can be divided into 4 categories.
• • Chronic maternal health factors
    • Maternal insulin-dependent diabetes mellitus (IDDM): As many as 30% of pregnancies in women with IDDM result in spontaneous abortion, predominantly in patients with poor glucose control in the first trimester.
    • Severe hypertension
    • Renal disease
    • Systemic lupus erythematosus (SLE)
    • Hypothyroidism and hyperthyroidism
  • Acute maternal health factors
    • Infections (eg, rubella, cytomegalovirus [CMV], and mycoplasmal ureaplasmal, listerial, toxoplasmal infections)
    • Trauma
  • Severe emotional shock
• Diseases and abnormalities of the reproductive system
  • Congenital or acquired uterine defects
  • Fibroids
  • Cervical incompetence
  • Abnormal placental development
  • Grand multiparity
• Exogenous factors
  • Caffeine
  • Alcohol
  • Tobacco
  • Cocaine

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Beta-human chorionic gonadotropin
• • This test is qualitative and, if results are positive, quantitative.
  • A higher likelihood of ectopic pregnancy or subsequent miscarriage exists if a beta-human chorionic gonadotropin (hCG) blood level is lower than predicted by the last menstrual period (LMP).
  • The possibility of molar pregnancy exists if beta-hCG is very high and out of proportion to predicted gestational age (GA).
• Hemoglobin and hematocrit: These studies establish baseline and detect hemorrhagic anemia.
• Blood type
• • Blood type must be documented for every pregnant patient with vaginal bleeding.
  • If Rh-negative, administer RhoGAM to prevent hemolytic disease of the newborn in this pregnancy and subsequent pregnancies.

Imaging Studies

• Ultrasound is used widely and is the imaging study of choice. Advantages of ultrasound include bedside use, availability, low cost, and noninvasiveness. Disadvantages include operator dependency.
• • Indications for ultrasound in the ED include severe symptoms (ie, intense pain, severe bleeding), open cervical os, pelvic mass, cervical motion tenderness, discrepancy between uterine size and LMP, and discrepancy between expected and measured beta-hCG levels.
  • A high-resolution vaginal ultrasound probe can detect pregnancy at 3-4 weeks' gestation and fetal heart activity at 5 and a half weeks.
  • Fetal studies are limited in the first trimester due to small fetal size. Ultrasound usually provides information in 3 major areas, ie, location of pregnancy, pregnancy size, and absence or presence of fetal cardiac activity.
  • An apparently empty uterus revealed by ultrasonography in a pregnant woman (ie, positive beta-hCG findings, LMP within last 20 wk) suggests a very early pregnancy (ie, <3 wk GA), a completed miscarriage, or an ectopic pregnancy.
  • The finding of a live fetus suggests a 95% chance of continued pregnancy.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Prehospital Care

• Obtain vital signs and establish an IV line in all pregnant patients who have abdominal pain and vaginal bleeding.
• If the patient is hypotensive, an IV bolus of normal saline (NS) is indicated for hemodynamic stabilization.
• Administer oxygen.

Emergency Department Care

• If tissue or blood clots are found in the cervical os, remove them with ring forceps to facilitate uterine contractions and hemostasis. For the same reason, use oxytocin in cases of severe bleeding (10-20 mcg/L of NS, wide open).
• Administer RhoGAM to a gravid patient who is Rh-negative and is experiencing vaginal bleeding.
• Use hemotransfusion in the case of severe bleeding.
• If the patient is in hemorrhagic shock, treatment includes the Trendelenburg position, oxygen with aggressive fluid resuscitation (at least 2 large-bore IV lines with lactated Ringer [LR] solution or NS, wide open), and hemotransfusion.

Consultations

All patients with the diagnosis of inevitable or incomplete abortion, patients with severe hemorrhage, or patients who are hemodynamically unstable require immediate obstetrics and gynecology (OB/GYN) consultation for definitive treatment. Definitive treatment invariably is evacuation of the products of conception from the uterus with curettage. Curettage may be done in the ED. Observe patients for 4-6 h after curettage, then discharge if no complications.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

The goals of pharmacotherapy are to prevent complications and reduce morbidity.

Drug Category: Oxytocic agent

These agents have vasopressive effects and prevent postpartum bleeding.

Drug Category: Immune globulin

May be used to suppress immune reactivity

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Outpatient Care

• Counsel all patients discharged from the ED (with any stage of abortion) regarding possible complications. OB/GYN follow-up in 1-2 days should be arranged.

Complications

• Postabortion bleeding
• Retained products of conception
• Hematometra
• Septic abortion

Patient Education

• For excellent patient education resources, visit eMedicine's Pregnancy and Reproduction Center and Procedures Center. Also, see eMedicine's patient education articles Miscarriage, Abortion, Ectopic Pregnancy, and Dilation and Curettage (D&C).

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to diagnose pregnancy: Perform pregnancy testing for every woman of childbearing age who presents with lower abdominal pain and/or vaginal bleeding. History alone is not sufficient to exclude pregnancy. Pregnancy is possible even if the patient gives a history of a recent normal menstrual period, lactation, or contraceptive use.
• Failure to diagnose ectopic pregnancy: An ectopic pregnancy must be excluded in every pregnant woman with abdominal pain and/or vaginal bleeding during the first or second trimester. Ectopic pregnancy is unlikely if definite findings include the following:
• • No cervical motion tenderness exists.
  • Uterine size and quantitative beta-hCG correspond to GA age by LMP.
  • No adnexal masses or tenderness exists.
  • If any doubt exists, an ultrasound is necessary to make a diagnosis. If the patient is hemodynamically unstable, do not delay treatment while waiting for ultrasound results.
  • To make the fastest diagnosis, the procedure of choice is culdocentesis, which can be performed during the pelvic examination. If any nonclotting blood is obtained from the cul-de-sac, the diagnosis almost certainly is ectopic pregnancy.
• Failure to prevent hemolytic disease of the newborn: Ascertain the blood type of every pregnant patient with vaginal bleeding. If the patient is Rh-negative, administer RhoGAM to prevent hemolytic disease of the newborn.
• Failure to assess the intensity of hemorrhage: External bleeding may not accurately reflect total hemorrhage. The patient, especially in the supine position, may collect large amounts of blood in the vagina with minimal external bleeding. Similarly, a large quantity of retained blood may be present in the uterine cavity and, in the case of ectopic pregnancy, in the peritoneal cavity.
• Never rely on the external examination to assess the rate of hemorrhage in patients with vaginal bleeding. Always perform a pelvic examination to look for blood collection in the vagina, disproportionally tender uterus, and signs of peritoneal irritation.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• ACEP Clinical Policies Committee. Clinical policy: critical issues in the initial evaluation and management of patients presenting to the emergency department in early pregnancy. Ann Emerg Med. 2003;41(1):123-33. [Medline].
• Andres RL, Larrabee KD. The perinatal consequences of smoking and alcohol use. Curr Probl Obstet Gynecol Fertil. 1996;19(5):171-204.
• Kleinhaus K, Perrin M, Friedlander Y. Patient age and spontaneous abortion. Obstet Gynecol. Aug 2006;108(2):369-77. [Medline].
• Miller JF, Williamson E, Glue J, et al. Fetal loss after implantation. A prospective study. Lancet. Sep 13 1980;2(8194):554-6. [Medline].
• Nielsen A, Hannibal CG, Lindekilde BE. Maternal smoking predicts the risk of spontaneous abortion. Acta Obstet Gynecol Scand. 2006;85(9):1057-65. [Medline].
• Rai R, Regan L. Recurrent miscarriage. Lancet. Aug 12 2006;368(9535):601-11. [Medline].
• Rulin MC, Bornstein SG, Campbell JD. The reliability of ultrasonography in the management of spontaneous abortion, clinically thought to be complete: a prospective study. Am J Obstet Gynecol. Jan 1993;168(1 Pt 1):12-5. [Medline].
• Schauberger CW, Mathiason MA, Rooney BL. Ultrasound assessment of first-trimester bleeding. Obstet Gynecol. Feb 2005;105(2):333-8.
• Scott JR. Early pregnancy loss. In: Danforth's Obstetrics and Gynecology. Philadelphia, Pa: JB Lippincott;1994:175.
• Sohaey R, Woodward P. The spectrum of first-trimester ultrasound findings. Curr Probl Diagn Radiol. Mar-Apr 1996;25(2):54-75. [Medline].
• Tongsong T, Srisomboon J, Wanapirak C, et al. Pregnancy outcome of threatened abortion with demonstrable fetal cardiac activity: a cohort study. J Obstet Gynaecol. Aug 1995;21(4):331-5. [Medline].
• Weiss JL, Malone FD, Vidaver J, et al. Threatened abortion: A risk factor for poor pregnancy outcome, a population-based screening study. Am J Obstet Gynecol. Mar 2004;190(3):745-50. [Medline].
• Wilcox AJ, Weinberg CR, O''Connor JF, et al. Incidence of early loss of pregnancy. N Engl J Med. Jul 28 1988;319(4):189-94. [Medline].

Article Last Updated: Aug 29, 2006