Impact of labor on outcomes in transient tachypnea of the newborn: population-based study.

OBJECTIVE: Our aim was to assess the effect of labor on the risk and course of transient tachypnea of the newborn (TTN) in term neonates from a contemporary, population-based cohort.

METHODS: We analyzed perinatal characteristics of term singleton newborns (gestational age [GA] of > or =37 completed weeks) who were born between January 2001 and December 2005 in the federal states of Hesse and Saarland (Germany). TTN was diagnosed on the basis of International Classification of Diseases, 10th Revision codes.

RESULTS: Of a total of 275 459 births, 239 971 fulfilled the inclusion criteria of GA of > or =37 completed weeks and singleton live birth. Among those, 13 346 term infants were admitted for neonatal care and 1423 were diagnosed as having TTN. The overall incidence of TTN was 5.9 cases per 1000 singleton live births in our study cohort. Elective cesarean section, low GA, male gender, and low birth weight were associated with TTN. The duration of oxygen supplementation for newborns with TTN was associated inversely with the duration of labor (r = -0.151; P = .028).

CONCLUSIONS: Our study indicates that TTN is strongly related to elective cesarean section and low GA. Furthermore, the absence of exposure to labor contractions is associated with increased risk and severe course of TTN at term, with longer duration of oxygen supplementation.