Breech at term. Early and late consequences of mode of delivery.

The present thesis analyses the impact of mode of delivery of term breech in a large Danish material from 1982-1995. For the first time a thorough investigation of foetal, neonatal and maternal shortterm and long-term outcomes provides a comprehensive picture with rates and correlations from the same population. The descriptive design has advantages over a randomised controlled trial – a much larger material in a relevant population and a longer follow-up period. But it has also disadvantages – the risk of bias that might influence the outcome. The present results reflect the clinical reality in a population with 45% elective caesarean, 17% intended vaginal, 34% emergency caesarean and 21% successful vaginal deliveries. In such a population we found that intended vaginal delivery was associated with a 15-fold increased risk of low 5 min Apgar score or intrapartum/early neonatal death. Low Apgar score was not predictable before the second stage of labour, but a prolonged second stage was a significant risk factor. By means of qualitative audit, a panel of experts blinded to outcome found that nearly half of the deaths during delivery or in the early neonatal period might have been avoided by improved care. The actual rates of foetal complications per 1000 intended vaginal deliveries, however, are low: 1.2 deaths, 17 infants with low Apgar score (5 ́<7), of which 3 developed a handicap or a minor disability. Furthermore, a small but significant correlation was found between term breech and cerebral palsy and epilepsy. This correlation could be ascribed to a higher frequency of being small for gestational age among breech infants. Elective caesarean section was associated with a higher risk of infections and haemorrhage than successful vaginal delivery, but emergency caesarean delivery was more often complicated than elective caesarean delivery. Therefore, elective caesarean delivery was not associated with increased risk of maternal complications when compared with intended vaginal delivery and emergency caesarean delivery. During the study period, there were no maternal deaths associated with elective caesarean delivery of term breech. Long-term complications and adverse foetal or maternal outcome in subsequent pregnancies were not increased after elective caesarean section. Altogether 75% of women with a term breech caesarean had a subsequent vaginal delivery. When the caesarean was elective, however, the subsequent delivery was more often by caesarean than when the breech had been delivered by emergency caesarean section. When informed of the small but significant risk of perinatal morbidity, most women with breech at term will probably choose a caesarean delivery. This implies that vaginal breech delivery is becoming a very rare event in the labour ward. However, there will still be women who consider the rewarding experience of a natural birth more important than the minimal risk of perinatal morbidity, and there will be women who arrive late in labour, where a caesarean delivery is no longer an option. In order to provide those women the best obstetric care, we need to continue to educate midwives and obstetricians in conduction of labour and the manual skills associated with vaginal breech delivery.