Association of Labor With Neonatal Respiratory Outcomes at 36–40 Weeks of Gestation

Abstract

OBJECTIVE: To evaluate whether labor is associated with lower odds of respiratory morbidity among neonates born from 36 to 40 weeks of gestation and to assess whether this association varies by gestational age and maternal diabetic status. METHODS: We conducted a secondary analysis of women in the Assessment of Perinatal Excellence obstetric cohort who delivered across 25 U.S. hospitals over a 3-year period. Women with a singleton liveborn non-anomalous neonate who delivered from 36 to 40 weeks of gestation were included in our analysis. Those who received antenatal corticosteroids, underwent amniocentesis for fetal lung maturity, or did not meet dating criteria were excluded. Our primary outcome was composite neonatal respiratory morbidity, which included respiratory distress syndrome, ventilator support, continuous positive airway pressure, or neonatal death. Maternal characteristics and neonatal outcomes between women who labored and those who did not were compared. Multivariable logistic regression models were used to evaluate the association between labor and the primary outcome. Interactions between labor and diabetes mellitus and labor and gestational age were tested. RESULTS: Our analysis included 63,187 women who underwent labor and 10,629 who did not. There was no interaction between labor and diabetes mellitus (P=.90). However, there was a significant interaction between labor and gestational age (P=.01). In the adjusted model, labor was associated with lower odds of neonatal respiratory morbidity compared with no labor for neonates delivered from 36–39 weeks of gestation. A 1-week increase in gestational age was associated with a 1.2 times increase in the adjusted odds ratio for the neonatal outcome comparing labor and no labor. CONCLUSION: Labor was associated with lower odds of the composite outcome among neonates delivered from 36–39 weeks of gestation. The magnitude of this association varied by gestational age. The association was similar for women with or without diabetes mellitus.

Association between Respiratory Morbidity and Labor in Pregnancies with Gestational Diabetes Mellitus

“…Furthermore, they found similar findings within their diabetic cohort which, unlike our study, included both pregestational and gestational diabetics. 23 The findings of our study also have several research implications. First, further research is needed to determine whether, among pregnancies complicated by GDM, the difference in neonatal respiratory morbidity is solely a function of labor or also a function of mode of delivery.…”

“…Second, it has been suggested that the protective effect of labor on neonatal respiratory outcomes can differ by gestational age. 23 Further research should be conducted to determine whether this is also seen in pregnancies complicated by GDM.…”

Short- and Long-Term Outcomes Associated with Large for Gestational Age Birth Weight

“…[35] The higher incidence of cesarean deliveries in LGA infants likely also increases the risk of respiratory complications in the newborn. [36] In addition, meconium aspiration may be more common in LGA infants. [4] LGA birth weight and shoulder dystocia Larger infants, especially with macrosomia, are at increased risk for shoulder dystocia, brachial plexus injury and clavicular fracture, [4 37 38] and the risk of birth injury increases with the severity of macrosomia.…”