Significant effects on neonatal morbidity and mortality after regional change in management of post-term pregnancy

Abstract

Objective: To evaluate the effects on neonatal morbidity of a regional change in induction policy for post-term pregnancy from 43(+0) to 42(+0) gestational weeks (GWs).

Design and setting: Nationwide retrospective register study between 2000 and 2007.

Population: All singleton pregnancies with a gestational age of >41(+2) GW (n= 119,198).

Methods: All Swedish counties were divided into three groups where study group allocation was designated by the proportion of pregnancies >42(+2) GW among all pregnancies of >41(+2) GW. Stockholm county formed a separate group.

Main outcome measures: Perinatal morbidity.

Results: In counties with the most active management, 19% of pregnancies >41(+2) GW were delivered at >42(+2) GW during 2000-2004 compared to 7.1% in 2005-2007. In the least active counties, corresponding figures were 21.0% compared to 19.4%. During 2005-2007, the odds ratios for meconium aspiration and 5-minute Apgar score of ≤6 in the least compared to most active counties, were 1.55 (95% CI: 1.03-2.33) and 1.26 (95% CI: 1.06-1.51). In Stockholm >42(+2) GW seen among pregnancies of >41(+2) decreased from 21.0% in 2000-2004 to 5.9% in 2005-2007. Reduced perinatal death risks by 48%, meconium aspiration of 51% and low Apgar scores by 31% in 2005-2007 compared with 2000-2004 were observed. Rates of operative deliveries at >41(+2) GW in Stockholm were unaltered.

Conclusion: A significant reduction in perinatal morbidity was found, with no influence on operative delivery rates for post-term pregnancy in Stockholm. We advocate a nationwide change toward more active management of post-term pregnancies.