Ultrasonographic foetal head circumference and cheek-to-cheek diameter at term as predictors of labour outcomes.

BACKGROUND

The clinical uses of ultrasonography have varied and increased over time, especially the ability of ultrasonographic measured parameters to predict the outcomes of labour. The proper understanding of the association between these ultrasonographic parameters, mode of delivery, adverse maternal and foetal outcomes will further improve patient counselling as well as the planning of intrapartum care.

AIM: The study explored the ultrasonographic measurement of foetal head circumference (HC) and cheek-to-cheek diameter (CCD) at term as predictors of labour outcomes.

METHODOLOGY: Eligible pregnant women at term were recruited from the antenatal clinic and had obstetric ultrasound scans done with HC and CCD measured. Maternal and foetal outcomes were measured and included progress in labour, obstetric lacerations, mode of delivery and suspected foetal distress. Data analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 20.

RESULTS

One hundred and thirty-two patients were recruited into the study. Foetal HC measurements ≥35 cm were closely associated with caesarean delivery odds ratio - 2.40 (95% confidence interval - 1.02-5.66. P = 0.046). Neither CCD nor CCD/HC ratio was predictive of the modes of delivery. The occurrence of perineal lacerations and poor progress of labour were observed more frequently with increasing HC and CCD.

CONCLUSIONS

HC performed well in predicting caesarean delivery as well as perinatal outcomes among parturients. The ultrasonographic measured HC (≥35 cm) is associated with a higher incidence of both obstetric interventions for poor progress of labour and adverse perinatal outcomes in comparison to CCD. The association between HC and labour dystocia was found to be linear. The CCD did not perform well as a predictor of the mode of delivery.