Perinatal antibiotic exposure of neonates in Canada and associated risk factors: a population-based study

Objective: To describe neonatal antibiotic exposures occurring immediately before and after birth and their associated risk factors. Methods: A retrospective review of the hospital charts of 449 mother-neonate pairs enrolled in the Canadian Healthy Infant Longitudinal Development national birth-cohort study was conducted at two tertiary hospitals and one rural hospital in Manitoba, Canada. The main outcome measures included the following: maternal and neonatal antibiotic use during the perinatal period; indications for antibiotic use, including suspected neonatal sepsis, maternal group B Streptococcus (GBS), premature rupture of membranes and caesarean-section; maternal health status, focusing on gestational hypertension, gestational diabetes, obesity and primigravida pregnancies. Results: During the perinatal period, 45.0% of neonates were exposed to antibiotics. Intravenous penicillin G (17%) and cefazolin (16%) were the most commonly administered intrapartum antibiotics. Colonization with GBS was confirmed in 21.2% of women and treated with antibiotics in 86% of cases. Overweight women and women with hypertension were significantly more likely to receive intrapartum antibiotics for caesarean section or GBS prophylaxis. Antibiotic treatment of the neonate was highest following emergency caesarean section (12%) or unknown maternal GBS status (20%). Conclusions: Neonates in Canada are routinely exposed to antibiotics during the perinatal period.