RESUMEN
OBJECTIVE: to study whether an increase in intrapartum referrals in primary midwife-led care births in the Netherlands is accompanied by an increase in caesarean sections. DESIGN: nationwide descriptive study. SETTING: the Netherlands Perinatal Registry. PARTICIPANTS: 789,795 births of nine year cohorts of women with low risk pregnancies in primary midwife-led care at the onset of labour between 2000 and 2008. MEASUREMENTS: primary outcome is the caesarean section rate. Vaginal instrumental delivery, augmentation with oxytocin, and pharmacological pain relief are secondary outcomes. Trends in outcomes are described. We used logistic regression to explore whether changes in the planned place of birth and other maternal characteristics influenced the caesarean section rate. FINDINGS: the caesarean section rate did not increase and was 5.5 per cent (range 4.9-6.3 per cent) for nulliparous women, and 1.0 per cent (range 0.8-1.1 per cent) for multiparous women. After controlling for the decline in planned home births and other maternal characteristics no increase in the caesarean section rate was found. The vaginal instrumental birth rate showed no increase, and was 18.1 per cent (range 17.9-18.5 per cent) for nulliparous women and 1.5 per cent (range 1.4-1.7 per cent) for multiparous women. Augmentation of labour and/or pharmacological pain relief increased from 24.0 to 38.8 per cent for nulliparous women, and from 5.4 to 10.0 per cent for multiparous women. CONCLUSION: the rise in intrapartum referrals was not accompanied by an increase in caesarean section rate over the period 2000-2008. Despite a considerable rise in the use of pain relief and augmentation, the rate of spontaneous vaginal birth remained high for low risk women who started labour in primary midwife-led care. IMPLICATIONS FOR PRACTICE: the current strict role division between primary care midwives and the obstetrician-led team increasingly results in a change in care provider during labour. In a more integrated care system, more women can receive continuous support of labour from their own primary care midwife, as long as only supportive interventions are needed.