Timing of Term Births and Associated Mortality Risks: Ecological Analysis Across 28 European Countries

Abstract

Objective

To explore term mortality rates in relation to rates of early-term birth (gestational ages 37 + 0 to 38 + 6 weeks), regarded as a proxy indicator of practices of elective birth by induction or caesarean.

Design

Ecological study using national birth data.

Setting

28 European countries.

Population

Births ≥ 37 weeks between 2015 and 2020.

Methods

Aggregated data on live and stillbirths by completed week of gestation was compiled from routine sources in the Euro-Peristat network. Countries were divided into three groups based on their percentages of early-term births using terciles (high, medium and low) and mortality rates were compared between groups with random-effects meta-analysis of proportions.

Main Outcome Measures

Stillbirths (antepartum or intrapartum fetal death) and perinatal death (stillbirth or early neonatal death) per 1000 total births ≥ 37 weeks.

Results

Early-term birth rates ranged from 17.8% (Iceland) to 49.1% (Cyprus), with terciles being < 21%, 21%–27%, and > 27%. Post-term birth rates were low in countries with higher early-term birth rates. The pooled stillbirth rate ≥ 37 weeks was 1.28 per 1000 total births (95% CI: 1.13–1.46) in the lowest tercile and 1.05 (95% CI: 0.95–1.16) in the highest (p = 0.05), but prediction intervals were wide reflecting heterogeneity within groups. No evidence of difference was seen between perinatal mortality rates by tercile (p = 0.71).

Conclusion

On average, the stillbirth rate was lower in countries where early-term birth rates were highest, but no difference was found in perinatal mortality rates. Heterogeneity was high within groups.