Delivery mode and intraventricular hemorrhage risk in very-low-birth-weight infants: Observational data of the German Neonatal Network

Abstract

Background

Very-low-birth-weight infants (VLBWI) are frequently delivered by cesarean section (CS). However, it is unclear at what gestational age the benefits of spontaneous delivery outweigh the perinatal risks, i.e. intraventricular hemorrhage (IVH) or death.

Objectives

To assess the short-term outcome of VLBWI on IVH according to mode of delivery in a population-based cohort of the German Neonatal Network (GNN).

Study design

A total cohort of 2203 singleton VLBWI with a birth weight <1500 g and gestational age between 22 0/7 and 36 6/7 weeks born and discharged between 1st of January 2009 and 31st of December 2015 was available for analysis. VLBWI were stratified into three categories according to mode of delivery: (1) planned cesarean section (n = 1381), (2) vaginal delivery (n = 632) and (3) emergency cesarean section (n = 190). Outcome was assessed in univariate and logistic regression analyses.

Results

Prevalence of IVH was significantly higher in the vaginal delivery (VD) (26.6%) and emergency CS group (31.1%) as compared to planned CS (17.2%), respectively. In a logistic regression analysis including known risk factors for IVH, vaginal delivery (OR 1.725 [1.325–2.202], p ≤ 0.001) and emergency cesarean section (OR 1.916 [1.338–2.746], p ≤ 0.001) were independently associated with IVH risk. In the subgroup of infants >30 weeks of gestation prevalence for IVH was not significantly different in VD and planned CS (5.3% vs. 4.4%).

Conclusions

Our observational data demonstrate that elective cesarean section is associated with a reduced risk of IVH in preterm infants <30 weeks gestational age when presenting with preterm labor.

Introduction

Significant progress in perinatal medicine over the last decades resulted in a remarkable decrease in neonatal morbidity and mortality [1]. It is still a matter of debate, though, whether mode of delivery affects the outcome of very-low-birth-weight infants (VLBWI).

Obstetricians are often in the uncomfortable position to decide how to deliver a preterm infant – vaginally or by cesarean section (CS). One of the main problems is that to date sufficient data of prospective randomized controlled trials (RCT) are not available and recommendations for clinical practice were taken from retrospective analyses.

For abnormal presentation or emergency situations, cesarean section is the recommended route of delivery for the infant [2], [3], [4]. Optimal mode for delivery of a preterm infant in vertex presentation remains controversial [5], [6], [7], [8], [9], [10], [11], [12] and data about neonatal outcome are inconsistent [5], [13], [14]. Some investigators showed no survival advantage [8], [14], [15], [16] or significant influence on neurodevelopmental outcome in extremely VLBWI [17], [18], [19] for planned CS. However, an increasing cesarean section rate of premature infants at low gestational ages [20], [21] may be explained by publications showing a better outcome after planned CS [5], [11], [22], [23]. In addition, some authors found cesarean section to reduce the risk of developing severe grades of IVH in premature infants <28 weeks [24], [25], [26].

Planned cesarean section seems to reduce postnatal risks for premature infants delivered at an early gestational age, but increases the risks for late preterm infants, causing a higher rate of mortality, morbidity and respiratory complications [26], [27].

In the German Neonatal Network we therefore investigated the influence of antenatal factors and mode of delivery on neonatal outcome in singleton birth infants born after preterm labor. Our aim was to use a large population-based cohort of VLBWI to derive a cut-off point (gestational week) below which planned CS is more likely to reduce morbidity in premature infants than vaginal delivery (VD).