Women's perception of pre-hospital labour duration and obstetrical outcomes; a prospective cohort study

Progress during early labour may impact subsequent labour trajectories. Women admitted to hospital in latent phase (<3 cm cervical dilation) labour have been shown to be at higher risk of obstetrical interventions.

We conducted a secondary analysis of data from a randomized controlled trial of 1247 healthy nulliparous women in spontaneous labour at term with a singleton fetus in cephalic presentation at seven hospitals in Southwestern British Columbia. We computed relative risks and their 95% confidence intervals to examine our primary outcome of cesarean section and secondary outcomes including obstetrical interventions and maternal and newborn outcomes according to women's perception of length of pre-hospital labour. Women were asked on admission to hospital how long they had been experiencing contractions prior to coming to hospital.

Women indicating that they had been in labour for 24 hours or longer at the time of hospital admission were at elevated risk for cesarean birth, relative risk (RR) 1.40, (95% Confidence Intervals 1.15-1.72), admission with a cervical dilation of 3 cm or less, RR 1.21 (1.07-1.36), more obstetrical interventions including continuous electronic fetal monitoring RR 1.11 (1.03-1.20), augmentation of labour RR 1.33 (1.23-1.44), use of narcotic RR 1.21 (1.06-1.37) and epidural analgesia RR 1.18 (1.09-1.28). Adverse neonatal outcomes did not differ apart from a significant increase in meconium-stained amniotic fluid RR 1.60 (1.09-2.35).

A single question asked of women on presentation to hospital was an important predictor of cesarean birth and may have utility in identifying women who would benefit from close observation and more active management of labour.