Mortality patterns among very preterm babies: a comparative analysis of two European regions in France and England.

OBJECTIVE: To explore the differences in outcome of very preterm pregnancies between two geographically defined populations in Europe with similar socioeconomic characteristics and healthcare provision but different organisational arrangements for perinatal care.

DESIGN: Prospective cohort study.

SETTING: Nord Pas-de-Calais (NPC), France, and Trent, UK.

PARTICIPANTS: All pregnancy outcomes 22(+0) to 32(+6) weeks' gestational age for resident mothers.

OUTCOME MEASURES: Mortality patterns (antepartum death, intrapartum death, labour ward death and neonatal unit death) among very preterm babies were analysed by region. Multinomial logistic regression was used to model regional differences for a variety of pregnancy outcomes and to adjust for regional differences in the organisation of perinatal care.

RESULTS: Delivery of very preterm infants was significantly higher in Trent compared with NPC (1.9% v 1.5% of all births, respectively (p<0.001)). Stillbirth rate was significantly higher in NPC than in Trent (23.0%, 95% CI 20.0% to 26.5% v 14.4%, 95% CI 12.3% to 16.6%, respectively (p<0.001)) and survival to discharge was higher in Trent than in NPC (74.6%, 95% CI 71.9% to 77.1% v 66.7%, 95% CI 63.3% to 69.9%, respectively (p<0.001)). Probability of intrapartum and labour ward death in NPC was more than five times higher than Trent (relative risk 5.3, 95% CI 2.2 to 13.1 (p<0.001)).

CONCLUSION: The high rate of very preterm deliveries and the larger proportion of these infants recorded as live born in Trent appear to be the cause of the excess neonatal mortality seen in the routine statistics. Information about very preterm babies (not usually included in routine statistics) is vital to avoid inappropriate interpretation of international perinatal and infant data. This study highlights the importance of including deaths before transfer to neonatal care and emphasises the need to include the outcome of all pregnancies in a population in any comparative analysis.