UK study of intrapartum care for low risk primigravidas: a survey of interventions.

STUDY OBJECTIVE: To determine the extent of intrapartum intervention received by primigravidas. DESIGN: Cross sectional survey of NHS hospitals in the UK. SETTING: One hundred and one randomly selected hospital maternity units. PARTICIPANTS: Forty consecutive primigravid women, judged to be at low risk at the start of labour, in each hospital. MAIN OUTCOME MEASURES: Seven groups of interventions or monitoring procedures were identified from the first, second, and third stages of labour: fetal monitoring, vaginal examinations, artificial rupture of membranes, augmentation of labour, pain relief, type of delivery, and episiotomy. Data were collected during 1993. MAIN RESULTS: Ninety eight hospitals took part in the study and data were collected on 3160 low risk primigravidas. Seventy four per cent of these women had continuous cardiotocography. The proportion of women having restrictive or invasive fetal monitoring showed appreciable geographical variation for both the first and second stages of labour. Using the criterion of a vaginal examination every four hours and allowing for the length of each woman's labour, 72% had more vaginal examinations than expected; there was a significant geographical variation in the number of women receiving more than five examinations. Fifty three per cent had artificial rupture of membranes; the procedure was performed over a wide range of cervical dilatations (0 cm-10 cm). Thirty eight per cent of labours were augmented, most commonly by intravenous syntocinon; the procedure showed significant geographical variation. Twenty eight per cent had a spinal block or epidural analgesia for the relief of pain; this intervention varied by geographical region only for the second stage of labour. Over one quarter of the women required instrumental delivery. Forty six per cent had an episiotomy; the frequency of this intervention varied substantially by region. There were no infant deaths. Twelve babies were recorded at birth as having a congenital anomaly. CONCLUSIONS: The rates of several interventions seem high for this low risk group and there was substantial geographical variation in the use of six interventions. Clinical trials are needed to evaluate the optimum criteria for using these interventions from which guidelines should be drawn up by local groups and the Royal College.