Maternal asthma and transient tachypnea of the newborn

Objective. To examine the relationship between transient tachypnea of the newborn and asthma complicating pregnancy. Design. Historical cohort analysis. Setting. Singleton live deliveries in New Jersey hospitals during 1989 to 1992 (n = 447 963). Patients. Mother-infant dyads were identified from linked birth certificate and maternal and infant hospital claims data. Women with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code (493) for asthma (n = 2289) were compared with a four-fold larger randomly selected control sample (n = 9156) from the remaining pool of women. Main Outcome Measure. Transient tachypnea of the newborn. Results. In the overall sample, after controlling for the confounding effects of important variables, infants of asthmatic mothers were more likely [odds ratio (OR), 1.79; 95% confidence interval (CI), 1.35-2.37] than infants of control mothers to exhibit transient tachypnea of the newborn. A stratified analysis by gestational age and sex revealed larger and statistically significant associations in term infants (OR, 2.02; 95% CI, 1.42-2.87) as opposed to preterm infants (OR, 1.51; 95% CI, 0.94-2.43) and in male infants (OR, 1.91; 95% CI, 1.35-2.71) as opposed to female infants (OR, 1.51; 95% CI, 0.92-2.47). On the other hand, after adjusting for important confounding variables, respiratory distress syndrome and maternal asthma were not found to be associated (OR, 1.14; 95% CI, 0.79-1.64). Conclusion. The results of this study provide evidence that maternal asthma is a risk factor for transient tachypnea of the newborn and differences in gestational age and sex were apparent in this association. The mechanism for this association remains to be determined.