Publication:

Predictive value of pre-induction cerebroplacental ratio for caesarean delivery due to foetal distress following induction of labour: a prospective observational study

Background Induction of labour is a commonly performed obstetric intervention when delivery is considered safer than continuation of pregnancy. Traditional parameters like the amniotic fluid index, estimated foetal weight and modified bishop score have been used to identify the development of foetal distress. This study focuses on the Cerebroplacental Ratio derived from Doppler assessment of the middle cerebral and umbilical arteries which provides information regarding foetal adaptation and the risk of foetal compromise during labour.

Methods A prospective observational study was conducted over 12 months among 305 antenatal women with singleton, cephalic pregnancies beyond 32 weeks of gestation undergoing induction of labour. Pre-induction Cerebroplacental ratio (CPR), amniotic fluid index (AFI), estimated foetal weight (EFW), and Modified Bishop Score were assessed within 24 hours before induction. The predictive performance of CPR was compared with AFI, EFW and Modified Bishop Score using appropriate statistical and diagnostic measures.

Results Among 305 women undergoing induction of labour, 213 (70%) had normal vaginal delivery and 92 (30%) underwent caesarean section. A CPR ≤1.1 was significantly associated with caesarean delivery and adverse neonatal outcomes. CPR ≤1.1 was also significantly associated with Apgar score <7 at 1 and 5 minutes. Among the parameters studied, CPR showed the highest sensitivity (45.54%), positive predictive value (58.08%) and diagnostic accuracy (39.02%) for adverse outcome.

Conclusion Pre-induction cerebroplacental ratio was found to be a better predictor of adverse perinatal outcome compared with AFI, estimated foetal weight and Modified Bishop Score in women undergoing induction of labour.