The WHO antenatal care randomised controlled trial: rationale and study design

The World Health Organisation and collaborating institutions in developing countries are conducting a multicentre randomised controlled trial to evaluate a new antenatal care (ANC) programme, consisting of tests, clinical procedures and follow-up actions scientifically demonstrated to be effective in improving maternal and newborn outcomes. These activities are distributed, for practical reasons, over four visits during the course of pregnancy and are aimed at achieving predetermined goals. The study is taking place in four countries, Argentina, Cuba, Saudi Arabia and Thailand. Recruitment of study subjects started on 1 May 1996. All 53 ANC clinical units had been enrolled by December 1996. Clinics in each country were randomly allocated (cluster randomisation) to provide either the new programme or the traditional programme currently in use. Approximately 24,000 women presenting for ANC at these clinics over an average period of 18 months will have been recruited. As women attending the control clinics receive the 'best standard treatment' as currently offered in these clinics, individual informed consent is requested only from women attending the intervention clinics. Authorities of the corresponding health districts and all participating clinics have provided written institutional informed consent before randomisation. The primary outcome of the trial in relation to maternal conditions is the rate of a morbidity indicator index, defined as the presence of at least one of the following conditions for which ANC is relevant: (a) pre-eclampsia or eclampsia during pregnancy or within 24 h of delivery; (b) postpartum anaemia (haemoglobin < 90 g/L); or (c) severe urinary tract infection/pyelonephritis, defined as an episode requiring antibiotic treatment and/or hospitalisation. The primary fetal outcome is the rate of low birthweight (< 2500 g). Adverse maternal and fetal outcomes are expected for approximately 10% of the control group. Several maternal and perinatal secondary outcomes are also considered. A comprehensive cost-effectiveness analysis and women's and providers' satisfaction evaluation are performed concurrently with the trial. Health-care programmes should be rigorously evaluated by randomised controlled trials, which are feasible in developing countries and should be conducted before introducing new treatments or health interventions.