Excerpt from Neonatology Considerations for the Pediatric Surgeon

Synonyms, Key Words, and Related Terms: neonatology considerations for the pediatric surgeon, gestational age, birth weight, low birth weight, LBW, small for gestational age, SGA, large for gestational age, LGA, intrauterine growth retardation or restriction, IUGR, neonatal fluid and electrolyte management, neonatal ventilatory management, neonatal medical diseases, delivery-room management of neonatal surgical conditions, surgery in newborns, neonatal surgery, short bowel syndrome, necrotizing enterocolitis, respiratory distress syndrome, RDS, bronchopulmonary dysplasia, patent ductus arteriosus, persistent pulmonary hypertension of the newborn, neonatal sepsis, early onset sepsis, late onset sepsis, renal tubular acidosis, apnea of prematurity, intraventricular hemorrhage, retinopathy of prematurity, congenital diaphragmatic hernia, abdominal wall defects, esophageal atresia

Please click here to view the full topic text: Neonatology Considerations for the Pediatric Surgeon

As a prerequisite to determine whether neonates fall into reference ranges, classify all infants based on gestational age (GA) and birth weight (BW). Early ultrasonography improved the accuracy of pregnancy dating, but discrepancies in dates, physical examination findings, and size require further evaluation. If prenatal care has been lacking, physical assessment remains the primary clinical determinant of gestational age. Gestational age is noted in completed weeks after the onset of the last menstrual period (LMP).

A term infant is an infant who is born after 37 completed weeks (ie, >37 0/7 wk gestation). A preterm infant is born before 37 completed weeks (ie, £37 wk gestation). A postterm infant is born at >42 0/7 weeks gestation.

Several terms are used to classify neonates according to their weight. These classifications aid the clinician in predicting clinical courses and outcomes. Low birth weight (LBW) neonates weigh less than 2500 grams, either because of prematurity, because they are small for their gestational age, or both. Very low birth weight (VLBW) neonates weigh less than 1500 grams (3 lb 5 oz) at birth.

Extremely low birth weight (ELBW) neonates weigh less than 1000 grams (2 lb 3 oz) at birth.

Small for gestational age (SGA) neonates are those who have a birth weight that is less than the 10th percentile for their gestational age. These infants are more prone to hypoxemia and meconium aspiration during labor from utero-placental insufficiency. They have a higher risk of polycythemia as well. They require special attention to prevent hypothermia and hypoglycemia. The placenta should be carefully examined by pathologists. These infants are at increased risk for developing necrotizing enterocolitis (NEC). They often have higher than normal caloric requirements for growth.

Large for gestational age (LGA) infants are those whose weight is greater than 90th percentile for their gestational age. These infants have a higher incidence of perinatal asphyxia and birth injury. These infants are at higher risk for hypoglycemia, hypocalcemia, polycythemia, and thrombocytopenia. Infants of mothers with diabetes are often large for gestational age.

Intrauterine growth retardation or restriction (IUGR) is used to describe neonates whose growth is not at the 10th percentile for their gestational age in utero or in neonates in whom the weight percentile is decreasing relative to their gestational age (ie, crossing the 10th percentile lines); these neonates may be small for gestational age. Abnormal growth patterns such as intrauterine growth retardation and smallness for gestational age can have long-term effects on the cardiovascular, endocrine, and neurologic systems. This has led to a rapidly growing field studying the fetal origins of adult diseases.

Please click here to view the full topic text: Neonatology Considerations for the Pediatric Surgeon

We subscribe to the
HONcode principles of the
Health On the Net Foundation

Medicine is a constantly changing science and not all therapies are clearly established. New research changes drug and treatment therapies daily. The authors, editors, and publisher of this journal have used their best efforts to provide information that is up-to-date and accurate and is generally accepted within medical standards at the time of publication. However, as medical science is constantly changing and human error is always possible, the authors, editors, and publisher or any other party involved with the publication of this article do not warrant the information in this article is accurate or complete, nor are they responsible for omissions or errors in the article or for the results of using this information. The reader should confirm the information in this article from other sources prior to use. In particular, all drug doses, indications, and contraindications should be confirmed in the package insert. FULL DISCLAIMER