Even the largest trial  has insufficient statistical power to detect a significant reduction in the perinatal mortality rate. To have an 80% chance of detecting a 50% reduction in a perinatal mortality rate of 3 per 1000, a sample size of 16,000 is required. Table 22.3 records the 13 perinatal deaths that occurred in the randomized trials, 3 among 3159 women allocated to induction and 10 among 3067 women allocated to selective induction. One normally formed baby, among those allocated to induction , died from asphyxia following emergency Caesarean section for meconium stained amniotic fluid and prolonged bradycardia 2 h following induction of labour. The other two deaths among those allocated to routine induction occurred in babies with lethal congenital anomalies. Three further deaths occurred in babies with anomalies among those allocated to selective induction. The other seven deaths occurred in normally formed babies. Two deaths in the Canadian Post-term Pregnancy Trial  occurred despite adherence to the monitoring protocol of daily movement counting and three times weekly CTG and ultrasound assessment of amniotic fluid volume. These babies were both small, weighing 2600 g and 3175 g. In the Dyson trial , a neonatal death from meconium aspiration occurred in a 43-week baby delivered for acute fetal bradycardia following spontaneous labour. Fetal heart rate monitoring and ultrasound assessment of amniotic fluid had been reassuring 48 h before the spontaneous onset of labour. One of the deaths in the Henry  trial was attributed to gestational diabetes. The second occurred due to meconium aspiration in a woman who refused induction following detection of meconium at amnioscopy. The deaths in the Bergsjo  and the Cardozo  trials were due to pneumonia and abruptio placentae, respectively.
The authors of the systematic reviews adopt a different approach to the inclusion of perinatal deaths in babies with fetal abnormalities. These are excluded in the Cochrane review  and included by Sanchez-Ramos . Thus, the Cochrane systematic review shows that induction of labour is associated with an significant reduction in perinatal mortality in normally formed babies (odds ratio 0.23; 95% CI 0.06-0.90), whileSanchez-Ramos confirms the reduction in the risk of perinatal death (0.9 versus 0.33%) but with the 95% confidence intervals for the odds ratio of 0.41 crossing unity (95% CI of 0.14-1.28).
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