Methodological considerations in the design of the WHO Antenatal Care Randomised Controlled Trial

We discuss methodological issues arising in a recent evaluation trial of a new antenatal care programme, as sponsored by the Special Programme of Research, Development and Research Training in Human Reproduction, and WHO's Division of Reproductive Health (Technical Support). The randomisation unit for the trial is the antenatal care clinic, with 53 clinics located in four countries randomly allocated to provide either the new programme or the traditional programme currently in use. Approximately 24,000 women presenting for antenatal care over an average period of 18 months will have been recruited.