Transient tachypnea of the newborn: effects of labor and delivery type in term and preterm pregnancies.
To determine whether timing or type of delivery affects the incidence of transient tachypnea of the newborn (TTN) in late preterm and term pregnancies. The cases of 85 newborns delivered at Fatih University Hospital and diagnosed with TTN between January 2006 and March 2009 were reviewed. For every newborn with TTN, four infants who were not transferred to the neonatal intensive care unit (n = 340) were randomly selected and adjusted for year of delivery. Findings for delivery type (cesarean [CS] + labor, elective CS [ECS], vaginal), gestational age at delivery, and other relevant parameters were compared in the TTN and control groups. Forty-five (53%) of the 85 TTN newborns were premature and 73 (86%) were delivered by CS. Multivariate regression analysis identified male gender, CS delivery, lower gestational age, absence of PROM as risk factors for onset of TTN. In the CS + labor and ECS subgroups, the risk of TTN was significantly higher for babies delivered prior to 38 weeks' gestation than for those delivered at 38 weeks or later (OR = 8.13 and 95%CI = 3.58-18.52 vs. OR = 7.14 and 95%CI = 2.81-18.18, respectively; p < 0.001 for both). However, there was no increased risk of TTN in either of these subgroups when babies delivered at 38 weeks' gestation were compared with those delivered at ≥39 weeks (p > 0.05). At all gestational ages investigated in the study, infants delivered vaginally were less likely to develop TTN than those delivered via CS + labor or ECS. Lower gestational age, CS delivery, and male sex are independent risk factors for TTN. Performing ECS no earlier than 38 weeks' gestation may decrease the risk of TTN. Labor before CS is not sufficient to decrease the frequency of TTN, even after 37 weeks of gestation, whereas vaginal birth appears be protective against TTN.