Week 13 Q&A

A mother comes to the emergency room in labor at 35 weeks' gestation and delivers immediately.

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Intrapartum antibiotics are not administered. She is from out-of-state and does not have a copy of her prenatal records. She denies any known abnormalities with her prenatal records but admits that she did not go very often. The baby is vigorous and crying. Apgar scores of 8 and 8 are given. The baby weighs 2,500 g and has the appearance of a late-premature infant. Mother reports her "water broke" a few hours ago. Hepatitis B vaccine is given. Vitamin K prophylaxis and erythromycin ointment is applied. STAT prenatal labs are obtained from the mother.

What is the recommended clinical management of the well-appearing late-preterm newborn whose mothers received inadequate GBS prophylaxis?

A. Well-appearing infants do not routinely require further diagnostic evaluation or special observation

B. Well-appearing infants born less than 37 weeks' gestation whose mothers did not receive adequate intrapartum GBS prophylaxis do not routinely require further diagnostic evaluation, but should be observed for ≥48 hours

C. All newborns born less than 37 weeks' gestation, regardless of intrapartum antibiotic use, should undergo full diagnostic evaluation and treatment pending cultures results with observation for ≥48 hours

D. Well-appearing infants born less than 37 weeks' gestation without adequate intrapartum GBS prophylaxis should undergo limited evaluation and observation for ≥48 hours

The correct answer is D. Universal screening for GBS colonization at 35 to 37 weeks' gestation and intrapartum prophylaxis has been highly successful in reducing the burden of neonatal GBS disease. Nonetheless, GBS infection is still the leading cause of early-onset sepsis in the newborn period. Early-onset GBS disease is defined as occurring in the first week of life. While neonatal GBS disease rates are down substantially, maternal colonization rates are stable, indicating the ongoing need for careful assessment of GBS risk factors before and during labor. Babies born with clinical signs of neonatal sepsis or whose mothers have signs of chorioamnionitis are at particularly high risk for GBS infection and require immediate treatment and a thorough evaluation. Babies who appear vigorous and healthy and whose mothers appear well may still be at risk for GBS disease. The Center for Disease Control and Prevention (CDC) has specific diagnostic and observation guidelines for the well-appearing newborn born with GBS risk factors. Maternal colonization with GBS is the primary risk factor for early-onset GBS disease. Risk factors for the newborn born to a mother with unknown GBS status at onset of labor include maternal history of prolonged rupture of membranes, premature delivery before 37 weeks' gestation and maternal fever. All mothers with GBS risk factors should receive intrapartum prophylaxis. Adequate intrapartum prophylaxis is considered ≥4 hours of an appropriate intravenous antimicrobial agent prior to delivery. For the nonallergic mother, penicillin remains the drug of choice for GBS prophylaxis. The premature newborn is at increased risk for GBS disease, particularly if the mother is colonized with GBS. Frequently GBS screening results are not available at the time of a premature birth. The CDC recommends that all mothers with the onset of labor before 37 weeks' gestation, with unknown GBS status, should be screened and given intrapartum antibiotic prophylaxis. The current recommendations for a well-appearing preterm infant born whose mother did not receive adequate intrapartum prophylaxis is a limited evaluation that includes complete blood count (CBC) differential, platelet count, and blood culture as well as in-hospital observation for clinical signs of sepsis for ≥48 hours after birth.

Source: Adams-Chapman I, Carlton D, Moore J. Neonatal-Perinatal Medicine Board Review. New York, NY: McGraw-Hill Education; 2016.