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.