Cesarean delivery reduces mortality risk in preterm breech births

Cesarean delivery reduces mortality risk in preterm breech births | Image Credit: © ondrooo - © ondrooo - stock.adobe.com.

Cesarean delivery (CD) is recommended in preterm breech births at 32 weeks’ gestation or sooner, according to a recent study published in the American Journal of Obstetrics & Gynecology.¹

Short- and long-term outcomes of very preterm (VPT) and extremely preterm (EPT) births are likely influenced by the mode of delivery.² CD is currently not recommended for preterm birth by guidelines, but a CD rate of 55% has been reported for VPT births.¹

CD may lead to complications such as respiratory disease syndrome (RDS), maternal morbidities, and subsequent preterm birth. However, this method of delivery may also reduce neonatal morbidity and intraventricular hemorrhage (IVH) risk in the case of preterm birth. This makes it difficult to determine the optimal mode of delivery.

To evaluate the link between mode of delivery and neonatal morbidity and mortality among births occurring at 32 weeks’ gestation or sooner, investigators conducted a systematic review and meta-analysis. Literature was identified through searches of the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases.

Two independent authors performed title, abstract, and full text screening, with a third author consulted to resolve disagreements. Studies evaluating preterm pregnancies up to 32 weeks’ gestation were eligible for inclusion.

Pregnancies with imminent threats to the mother or fetus were excluded from the analysis. Neonatal mortality and severe IVH were reported as the primary outcomes, separated by mode of delivery.

Secondary outcomes included Apgar scores at 1 and 5 minutes, RDS, periventricular leukomalacia (PVL), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), late neurodevelopmental complications, early onset sepsis, late-onset sepsis, and maternal morbidities.

Data extractions was performed by 2 independent authors using Microsoft Excel 2019. Relevant data included first author, year of publications, country, study design, study duration, study population, number of participants, object identifier, outcome events, and mode of delivery.

There were 17 studies included in the quantitative analysis and 19 in the qualitative analysis. All studies were cohort studies, and 9 reported on the actual mode of delivery, 6 the planned mode of delivery, and 2 both the planned and actual mode of delivery.

Across 9 studies evaluating the link between mode of delivery and mortality among preterm infants, a pooled odds ratio (OR) of 0.62 was reported for actual CD, indicating significantly improved survival. For planned CD vs planned vaginal delivery (VD), no significant difference was noted, with an OR of 0.87.

Mortality odds were not significantly impacted by CD in singleton vertex preterm pregnancies, with an OR of 0.90. However, among singleton breach pregnancies, an OR of 0.34 for death was reported among infant born through actual CD vs actual VD, indicating a 66% reduced risk of mortality. For planned CD and VD, this OR was 0.56.

When evaluating the odds of IVH based on mode of delivery, significantly reduced odds were reported among CD infants during VD infants, with an OR of 0.70. However, severe IVH risks did not differ based on planned or actual mode of delivery. PVL and ROP odds also did not differ between delivery methods.

For BPD, no significant difference in risk was reported based on the planned mode of delivery. However, when evaluating the actual mode of delivery, reduced odds were identified from CD in 1 study. NEC rates also did not differ between methods, but 1 study reported higher sepsis odds in CD infants. Apgar scores did not differ between groups.

These results indicated reduced mortality without increased morbidity from CD in VPT and EPT breech infants. Investigators concluded routine CD is preferred for preterm singleton breech pregnancies at 32 weeks’ gestation or sooner.

References

1. Unger V, Gasparics A, Nagy Z, et al. Cesarean delivery is associated with lower neonatal mortality among breech pregnancies: a systematic review and meta-analysis of preterm deliveries ≤32 weeks of gestation. American Journal of Obstetrics & Gynecology. 2024;231(6):589-598. doi:10.1016/j.ajog.2024.06.015
2. Costa STB, Costa P, Graça AM, Abrantes M, Portuguese National Registry of very low birth weight infants. Delivery mode and neurological complications in very low birth weight infants. Am J Perinatol. 2024;41(9):1238-1244. doi:10.1055/a-1815-1842