The CAP Study
Women with a history of pre-eclampsia in their most recent pregnancy who agreed to participate, received calcium 500mg daily or placebo from enrolment until they become pregnant, and up to 20 weeks of pregnancy. All women received calcium 1500mg daily after 20 weeks as per WHO recommendations. The primary outcome is pre-eclampsia.
CAP study progress
The main paper has been completed and submitted for assessment for publication. Several sub-studies are on-going, including urinary calcium:creatinine and protein:creatinine ratio studies, as well as secondary analyses of the trial data.
A striking feature of the CAP study was the enthusiasm of the participants, many of whom took calcium or placebo for several years.
The study was a good example of the general observation that participants of research studies overall do better than non-participants. For women with pregnancies progressing beyond 20 weeks, the overall rate of eclampsia was 1.6% compared with 19% in the previous pregnancy, and of stillbirth was 10.4% compared with 57.5% in the previous pregnancy. Of course, part of this improvement is due to the tendency for pre-eclampsia risk to improve with subsequent pregnancies, but it is also almost certainly contributed to by the empathetic, personal care provided by the research teams, and the fact that all participants were provided with the WHO-recommended supplementation with 1.5g of calcium from 20 weeks of pregnancy till the birth, which has been shown to reduce the severe consequences of pre-eclampsia.