Outcomes of independent midwifery attended births in birth centres and home births: a retrospective cohort study in Japan.

OBJECTIVE: the objective of this study was to describe and compare perinatal and neonatal outcomes of women who received care from independent midwives practicing home births and at birth centres in Tokyo.

DESIGN: a retrospective cohort study.

SETTINGS: birth centres and homes serviced by independent midwives in Tokyo.

PARTICIPANTS: of the 43 eligible independent midwives 19 (44%) (10 assisted birth at birth centres, nine assisted home birth) participated in the study. A total of 5477 women received care during their pregnancy and gave birth assisted by these midwives between 2001 and 2006.

METHODS: researchers conducted a retrospective chart review of women's individual data. Collected data included demographic characteristics, process of pregnancy and perinatal and neonatal outcomes. We also collected data about independent midwives and their practice.

FINDINGS: of the 5477 women, 83.9% gave birth at birth centres and 16.1% gave birth at home. The average age was 31.7 years old and the majority (70.6%) were multiparas. All women had vaginal spontaneous deliveries, with no vacuum, forceps or caesarean section interventions. No maternal fatalities were reported, nor were breech or multiple births. The average duration of the first and second stages of labour was 14.9 hours for primiparas and 6.2 hours for multiparas. Most women (97.1%) gave birth within 24 hours of membrane rupture. Maternal position during labour varied and family attended birth was common. The average blood loss was 371.3mL, while blood loss over 500mL was 22.6% and over 1000mL was 3.6%. Nearly 60% of women had intact perinea. There were few preterm births (0.6%) and post mature births (1.3%). Infant's average birth weight was 3126g and 0.5% were low-birthweight-infants, while 3.3% had macrosomia. Among primiparas, the birth centre group had more women experiencing an excess of 500mL blood loss compared to the home birth group (27.2% versus 17.6% respectively; RR 1.54; 95%CI 1.10 to 2.16). Multiparas delivering at birth centres were more likely to have a blood loss over 500mL (RR1.28; 95%CI 1.07 to 1.53) and over 1000mL (RR1.75; 95%CI 1.04 to 2.82) compared to women birthing at home.

CONCLUSION: our results for birth outcomes with independent midwives at birth centres and home births in Japan indicated a high degree of safety and evidence-based practice. This study had some limitations because of its incomplete data and low response rate. However, this is one of the few studies that reported outcomes of Japanese independent midwives and the safety of their practice. A birth registry system would provide us with more accurate and complete information of all childbirths with which to evaluate the safety of independent Japanese midwives.