Who should provide routine antenatal care for low-risk women, and how often? A systematic review of randomised controlled trials. WHO Antenatal Care Trial Research Group.

Many activities, the timing and the frequency of visits of conventional antenatal care provided to low-risk pregnant women have most often been introduced without proper scientific evaluation. Few trials, to date, have been conducted to evaluate the effectiveness of antenatal care programmes for low-risk women with varied number of antenatal visits and type of care providers. We have performed a systematic review of these randomised controlled trials. Five randomised controlled trials were identified in which the effectiveness of a schedule of reduced number of antenatal visits (n = 12,883) was compared with the existing practice (n = 9438). Four of these trials were carried out in developed countries. The difference in the number of visits between intervention and control arms of the trials was moderate. Only one trial achieved a reduction in the median number of visits, from six in the standard care to four in the intervention group, that could be considered to be of health-care relevance for the study population. No significant differences were observed in the two arms of the trials when low birthweight, small-for-gestational-age, Caesarean section, induction of labour, antepartum haemorrhage and postpartum haemorrhage were considered as outcome measures. However, there was a tendency towards an increased rate of preterm delivery in the intervention group in three of the trials. Conversely, the largest trial in Harare, Zimbabwe, demonstrated a statistically significant reduction in preterm delivery in the intervention group (relative risk [RR] 0.88; 95% confidence interval [CI] 0.80, 0.96). Neither the individual studies nor the review had the statistical power to evaluate mortality outcome variables. When perception of care was assessed, women participating in two trials expressed less satisfaction with frequency of visits in the experimental group. In the London, UK, trial, some women in the reduced number of visits group felt that their expectations were not completely fulfilled. However, an opposite trend was reflected when women were asked for their preference of the type of care for any future pregnancy. We also identified three trials that compared midwife/general practitioner-managed care vs. obstetrician/gynaecologist-led shared care. The results were indicative of similar clinical efficacy of the two groups. However, women's response regarding the continuity of care favoured midwife-led care. From the health economics perspective, there is evidence of cost reduction if antenatal care was provided by staff other than the obstetrician/gynaecologist. The available data demonstrate no significant differences in selected perinatal outcomes for low-risk women receiving care according to a reduced frequency (approximately two visits fewer) of prenatal visits vs. those following the existing practice. However, there are differences in satisfaction with the prenatal care provider and the prenatal care system. There is evidence that a midwife's clinic for provision of antenatal care for low-risk pregnancies is feasible and therapy reduction in costs achievable.