Evidence from US suggests that trials will not alter obstetric behaviour

Home births are currently rare and controversial in the United States. The most recent national figures show that in 1992 only 0.6% of infants were born at home.1 The attendants for these 25923 births were certified nurse-midwives (11.5%), physicians (18.1%), other midwives (31.9%), and others (38.5%). In many areas it is difficult or impossible to find a trained attendant for a home delivery, and hospital back up is almost non-existent. Mother and birth attendant often encounter suspicion and hostility if an obstetric problem necessitates transfer to hospital. Physicians and nursemidwives who attend home births may be denied malpractice coverage or have hospital admitting privileges revoked. Lay midwives increasingly face arrest and prosecution for practising without a state licence. In this atmosphere, home delivery is not a viable option for most American mothers.

Home births evoke strong emotions among health professionals, and attitudes are rarely based on research data. Proponents argue that home deliveries for women who are at low risk of complications during pregnancy and delivery have perinatal outcomes as good as or better than hospital births. Opponents, including the American College of Obstetrics and Gynecology, argue that unexpected complications may arise during any labour, making hospital delivery a safer option for all women. Studies have compared the safety of home and hospital births in Missouri,2 Tennessee,3 North Carolina,4 Kentucky,5 and Washington State.6 Neonatal morbidity and mortality did not differ between planned home deliveries and hospital births when care included continuous risk assessment and a qualified birth attendant. However, studies of home births have had methodological problems, which have weakened their findings. These flaws included lack of randomisation, selection bias, inadequate sample sizes, confounding, and incomplete data.7 As Dowswell and colleagues note, the safety of home birth is not likely to be established by a randomised controlled trial because most women would probably refuse to be randomly allocated a birth place and a large sample size would be required to detect adverse outcomes. Nevertheless, safety remains a paramount consideration, and descriptive and casecontrol studies of perinatal outcomes must continue.

The proposed randomised controlled trial of the effect of birth setting on maternal anxiety and breast feeding could illuminate important aspects of the experience of home birth that have received little attention. In a similar vein, nurse-midwives in California recently proposed that research on home birth should expand beyond morbidity and mortality to study women's subjective birth experiences, the appropriate use of technology in home deliveries, and the influence of the birth environment on labour.8 Soft outcomes such as empowerment, satisfaction, and family bonding also warrant study, although they are difficult to measure.

Methodologically sound research alone is unlikely to change obstetric thinking about home delivery, even if psychological and health benefits are shown. In recent decades the findings of randomised controlled trials have rarely moderated the increasing application of obstetric technology to childbirth. Examples include the use of routine ultrasonography and electronic fetal monitoring despite findings that these measures do not improve outcomes. In addition to scientific studies, the consumer movement and social forces such as the drive to decrease health care costs may be important in determining birth options in the future.