Infant and maternal outcomes in the pregnancies of asthmatic women

We examined the relationship between infant and maternal outcomes and asthma complicating pregnancy, using historical cohort analysis of singleton live deliveries in New Jersey hospitals between 1989 and 1992 (n = 447,963). Subject mother-infant dyads were identified from linked birth certificate and maternal and newborn hospital claims data. Women with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code (493) for asthma (n = 2,289) were compared with a fourfold larger randomly selected control sample (n = 9,156) from the remaining pool of women. After controlling for the effects of important confounding variables, maternal asthma was associated with the following adverse infant outcomes: preterm infant (odds ratio [OR] = 1.36; 95% confidence interval [CI], 1.18 to 1.55), low birth weight (OR = 1.32; 95% CI, 1.10 to 1.58), small-for-gestational age (OR = 1.26; 95% CI, 1.10 to 1.45), congenital anomalies (OR = 1.37; 95% CI, 1.12 to 1.68), and increased infant hospital length of stay (OR = 1.44; 95% CI, 1.25 to 1.65). The adverse maternal outcomes associated with maternal asthma were: pre-eclampsia (OR = 2.18; 95% CI, 1.68 to 2.83), placenta previa (OR = 1.71; 95% CI, 1.05 to 2.79), cesarean delivery (OR = 1.62; 95% CI, 1.46 to 1.80), and increased maternal hospital length of stay (OR = 1.86; 95% CI, 1.60 to 2.15). The results emphasize the need for maternal asthma to be added to the list of conditions that increase the risk of adverse pregnancy outcomes.