To investigate the effect of maternal antibiotics, given in the predelivery period, on neonatal outcomes.
Retrospective cohort study.
A single level 3 neonatal intensive care unit.
All infants with birth weights 1500 g or less cared for from July 1994 to July 2000 (n = 834) were included in the study. Mothers were classified as receiving antibiotics if they received any parenteral antibiotics in the predelivery period. Infants whose mothers received antibiotics were compared with infants whose mothers received no antibiotics.
Main Outcome Measures
The main outcome variables studied included intraventricular hemorrhage (IVH), cystic periventricular leukomalacia (PVL), sepsis, and mortality.
Of 834 mothers, 374 (45%) received antibiotics prior to delivery. On univariate analysis, there were no differences in the relative risk (RR) of mortality (1.26; 95% confidence interval [CI], 0.86-1.79) or grades 3 to 4 IVH (RR, 1.39; 95% CI, 0.82-1.90) between the antibiotics and no-antibiotics groups. Infants born to mothers receiving antibiotics had an increased risk of culture-proven sepsis (RR, 1.4; 95% CI, 1.02-1.64) and a decreased risk of cystic PVL (RR, 0.26; 95% CI, 0.09-0.79) compared with infants whose mothers did not receive antibiotics. After controlling for confounding variables, maternal antibiotics were not associated with a decrease in the risk of mortality (adjusted risk [AR], 1.0; 95% CI, 0.5-2.1), grades 3 to 4 IVH (AR, 1.0; 95% CI, 0.5-1.9), or sepsis (AR, 0.9; 95% CI, 0.7-1.4). However, the use of maternal antibiotics was associated with a decreased risk of developing cystic PVL (AR, 0.09; 95% CI, 0.02-0.5).
In our population of very low-birth-weight infants, maternal antibiotics were associated with a decreased risk of cystic PVL. Maternal antibiotics do not change the risk of mortality, sepsis, or severe IVH.