Term breech delivery in The Netherlands

Abstract

The management of the term breech delivery has been a subject of discussion for many years. Only a few randomized trials had been performed on outcome in relation to the mode of delivery in case of breech position. In october 2000 the results of the Term Breech Trial (TBT) were published, in which women with a term fetus in breech were randomly assigned for planned caesarean section (CS) or planned vaginal delivery. The results showed a significantly lower perinatal mortality and morbidity after planned CS. Until 2000 the CS rate in The Netherlands among term breech was 50%, of which half were planned and half were emergency CS's after vaginal onset of labour. Following the publication of the results of the TBT this rate increased in two months from 50% to 80% and remained stable thereafter. In this thesis several studies on perinatal outcome after planned CS as compared to planned vaginal delivery of the term breech in The Netherlands are described. Results of an analysis of the five-year period prior to the TBT on perinatal outcome of more than 33,000 term infants, using data from the Dutch Obstetric Registry (LVR-2), showed similar results as the TBT: a trial of labour resulted in a seven-fold increase in low Apgar score, a three-fold increase in birth trauma and a two-fold increase in perinatal mortality, compared to planned CS. The fast and large change in CS rate had it's effect on perinatal outcome. Analysis on outcome of more than 35,000 term breech infants, performed on the 33-months period prior to and the 25-months period after the TBT, showed that the change in policy had resulted in an improved perinatal outcome. Mortality decreased from 0.35% to 0.18%, low five-minute Apgar (‹ 7) score from 2.4% to 1.1% and birth trauma from 0.29% to 0.08%. Analysis of the years after the TBT, using linked data from the Dutch Obstetric and Neonatal Registry enabled us to study perinatal outcome in more detail. Even with a decline of vaginal deliveries of term breech infants after the TBT, perinatal outcome among more than 11,000 term infants remained worse after a planned vaginal delivery, with an excess of perinatal mortality / morbidity of more than 1%, as compared to planned CS. To investigate which factors contributed to the extraordinary fast and large change in policy concerning term breech delivery, a questionnaire survey was held among all 100 Dutch obstetric departments. Patient influence seemed to be the most important factor for the change in medical practice in case of term breech. Analysis on gender differences revealed that from 31 weeks onwards there are significantly more girls in breech position. Perinatal outcome is worse for boys, with higher mortality and morbidity, irrespective of the mode of delivery. Breech position clearly appears to be associated with a significantly higher prevalence of congenital malformations than vertex postion and in both positions a male excess is found regarding almost all congenital malformations.