Fear of childbirth (FOC) causes suffering in pregnant women and disabling their adaptation to the childbirth process. However, FOC remains undetected and untreated in the Dutch midwifery care. The aims of this thesis were to examine how to improve assessment and treatment of FOC under the care of midwives. First, we found in an observational study that catastrophizing labour pain and not the labour pain intensity was the strongest and independent predictor for requesting and undergoing epidural anaesthesia during labour. In another observational study we found that the new one-item Fear of Childbirth-Postpartum-Visual Analogue Scale (FOCP-VAS) was a useful tool in predicting pregnant women-requested and received non-urgent obstetric interventions during childbirth. In a randomized controlled trail, which was announced with a publication of the study protocol, we found that nine weeks of Mindfulness Based Childbirth and Parenting (MBCP) was significantly superior to enhanced care as usual (ECAU; fear consultation and writing a childbirth plan) in decreasing FOC, catastrophizing of labour pain, preference for non-urgent obstetric interventions, and increasing acceptance of labour pain and unmedicated childbirths. MBCP participants were: less likely to undergo epidural anaesthesia (33%); less likely to undergo self-requested caesarean section (50%); and twice as likely to have unmedicated childbirth relative to ECAU. Besides, we found that MBCP had more effects and lower costs with the high probability of MBCP to be cost-effective (at a willingness to pay of zero). Finally, we found that greater mindful awareness was the only significant mechanism of change leading to unmedicated, thus, natural childbirths.