Elective Cesarean Section at 37 Weeks Is Associated with the Higher Risk of Neonatal Complications

Abstract

Elective Cesarean section performed before 39 weeks of gestation may be associated with increased risk of neonatal complications. We retrospectively investigated differences in the neonatal complication rate between 684 newborns delivered by elective Cesarean section at 37 weeks of gestation (n = 390) and those delivered by the same procedure at 38 weeks (n = 294) between 2006 and 2012 at our hospital in order to ascertain whether adverse outcomes differ between the groups. Newborns delivered at 37 weeks had a significantly higher incidence of neonatal intensive care unit admission (p = 0.03), adverse respiratory complications (p < 0.01), low birth weight (p < 0.001), and hypoglycemia (p < 0.005) than those delivered at 38 weeks. Compared with normal weight neonates, low birth weight neonates were more likely to have hypoglycemia (p < 0.001). Multivariate logistic regression analysis revealed that an adverse respiratory outcome was independently associated with gestational age (p < 0.01; odds ratio [OR], 3.26; 95% confidence interval [CI], 1.36-7.81), while hypoglycemia was independently associated with birth weight (p < 0.01; OR, 16.34; 95% CI, 7.72-34.56). Respiratory disorders were significantly associated with gestational age even in normal birth weight newborns without any other complications such as hyperbirilubinemia, hypoglycemia or bacterial infections. In conclusion, the incidence of neonatal complications was higher in newborns delivered at 37 weeks of gestation than in those delivered at 38 weeks via elective Cesarean section. Thus, the procedure should be scheduled at 38 weeks to improve neonatal outcomes.

Association between uterine contractions before elective caesarean section and transient tachypnoea of the newborn: a retrospective cohort study

“…Previous reports indicate that a caesarean section at 37 weeks is a major TTN risk factor,29 30 and our findings support this conclusion. In our study, 16 (21.1%) of 76 women with no uterine contractions who underwent a caesarean section at 37 weeks delivered an infant who developed TTN (data not shown).…”

A systematic review and time-response meta-analysis of the optimal timing of elective caesarean sections for best maternal and neonatal health outcomes

“…Doan et al, Gawlik et al, McAlister et al, Nir et al, and Zanardo et al reported outcomes for 37 + (0–6) + 38 + (0–6) WG versus ≥39 + 0 WG and not for individual weeks [ 44 – 46 , 48 , 49 ]. There were two studies from Japan and one from Germany that compared 37 + (0–6) WG to 38 + (0–6) [ 41 ] [ 43 ]. [ 42 ] They all showed similar results like the other studies; less NICU admission in the later WG.…”

“…One study, Wilmink et al examined only twin births. Two studies from Japan, Nakashima et al and Yamazaki et al, and one from Germany, Gawlik et al, only compared the 37 + (0-6) to the 38 + (0-6) WG and four, Doan, McAlister, Nir and Zanardo et al, did not report the single WG but compared 37 + (0-6) + 38 + (0-6) to ≥39 + (0-6) week [41][42][43][44][45][46][47][48][49]. These eight studies could not be included in any meta-analysis.…”

Maternal characteristics and neonatal outcomes of emergency repeat caesarean deliveries due to early‐term spontaneous labour onset

“…One of the main reasons to schedule an elective caesarean delivery at early term (between 37 + 0/7 weeks and 38 + 6/7 weeks of pregnancy) is to avoid an unscheduled in‐labour repeat caesarean delivery 5,6 . Out‐of‐hours, emergency caesarean deliveries have been associated with increased rates of physical and psychological complications of mothers and infants 5,7 …”

“…Some institutions choose elective caesarean sections at 37 weeks gestation; however, the frequency of neonatal complication is reported to be even higher in those at 37 weeks than at 38 weeks 6,8 . For these reasons, many of the institutions perform elective caesarean deliveries at 38 weeks gestation 4,6,8 .…”