The CAP Study
Women with a history of pre-eclampsia in their most recent pregnancy who agree to participate in the study, receive calcium 500mg daily or placebo from enrolment until they become pregnant, and up to 20 weeks of pregnancy. The primary outcome is pre-eclampsia.
CAP study progress
Since the year-end dip, recruitment has improved. Our plan is to stop recruitment on April 30, 2016, and achieve our target of 540 pregnancies that progress beyond 20 weeks’ gestation by April 2017. The results will be available in the second half of 2017.
Start-up meeting for All Children Thriving (ACT) award
The kick-off meeting for the All Children Thriving (ACT) award will take place in Cape Town on May 12, 2016. This is collaboration between the CAP Study, Global Pregnancy Collaboration (CoLab), PATH, University of British Columbia, University of Stellenbosch and Lifeassay Diagnostics (Pty) Ltd. Urine samples collected from the CAP study will be used to assess the accuracy of a unique, low-cost urine protein creatinine strip test, in relation to other strip tests and laboratory assays. The value in this collaboration is to validate this potentially accurate test for the prediction and diagnosis of pre-eclampsia. If found to be clinically useful, such a test would have implications for pre-eclampsia screening, especially beyond tertiary care centres, such as ANC programs and home based settings for women who have limited access to antenatal care.
Related work and sub-studies:
Calcium for preventing hypertension
Gabriela Cormick, Jose Belizan and colleagues have completed a Cochrane systematic review ‘Calcium supplementation for preventing primary hypertension.’ which found a small but statistically significant reduction in both systolic and diastolic blood pressure in adults treated with calcium (supplementation or food fortification) versus placebo or control.
The CAP study is generating a unique database on women with previous pre-eclampsia followed prospectively before their pregnancy to their next birth. At last count more than 30% of these women experienced recurrent pre-eclampsia. We encourage our team to use these data by proposing relevant ancillary studies. We would also welcome proposals from the wider PRE-EMPT group. We have previously received IRB approval for six ancillary studies.
Calcium supplementation, diet and weight
Gabriela Cormick has proposed an additional ancillary study: “The effect of calcium intake on body weight in pregnant women from South Africa, Zimbabwe and Argentina participating in the Calcium and Preeclampsia trial.” Previous studies have shown an inverse relationship between calcium intake and body weight, and a reduction in body weight with calcium supplementation. The CAP study data provides an opportunity to measure the effects of calcium supplementation on non-pregnant women’s weight, as well as weight gain during pregnancy. We are also conducting dietary assessments of women at 20 weeks of pregnancy. These data will provide information on whether the effect of calcium on weight is in part mediated by appetite.
Hofmeyr GJ, Novikova N, Singata M, Fawcus S, Oyebajo A, Munjanja S, Belizán JM. Protocol 11PRT/4028: Long term calcium supplementation in women at high risk of pre-eclampsia: a randomised, placebo-controlled trial (PACTR201105000267371) http://www.thelancet.com/protocol-reviews/11PRT-4028
Hofmeyr G, Belizán J, von Dadelszen P; the Calcium and Pre-eclampsia (CAP) Study Group. Low-dose calcium supplementation for preventing pre-eclampsia: a systematic review and commentary. BJOG. 2014 Mar 13. doi: 10.1111/1471-0528.12613
Seuc AH, Peregoudov A, Betran AP, Gulmezoglu AM. Intermediate outcomes in randomized clinical trials: an introduction. Trials. 2013;14:78.
Hofmeyr GJ, Lawrie TA, Atallah AN, Duley L, Torloni MR. Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems. Cochrane Database Syst Rev. 2014 Jun 24;6:CD001059
Cormick G, Ciapponi A, Cafferata ML, Belizan J. Calcium supplementation for prevention of primary hypertension. Cochrane Database Syst Rev 2015 Jun 30;6:CD010037.
Hofmeyr GJ, Seuc A, Betrán AP, Purnat T, Ciganda A, Manyame S, Munjanja SP, Singata M, Fawcus S, Frank K Hall DR, Cormick G, Roberts J, Bergel E, Drebit S, von Dadelszen P, Belizan J on behalf of the calcium and Pre-eclampsia Study Group*. The effect of calcium supplementation on blood pressure in non-pregnant women with previous pre-eclampsia: an exploratory, randomized placebo controlled study (WHO Study A65750). Pregnancy Hypertens. 2015 Oct;5(4):273-9
Hofmeyr GJ, for the Calcium and Pre-eclampsia (CAP) Study Group. Calcium supplementation for preventing pre-eclampsia/eclampsia. Africa Regional Meeting for Interventions for Impact in essential obstetric and newborn care. Addis Ababa 21-25 February 2011.
Hofmeyr GJ, Singata M, Fawcus S, Belizan JM, Oyebajo AB, Munjanja SP, Sawchuck D, von Dadelzsen P, Bergel E, Betran AP, Purnat T, Tahuringana E.Long term calcium supplementation in women at high risk of pre-eclampsia: a randomized, placebo-controlled trial. 31st Conference on Priorities in Perinatal Care in Southern Africa. Kruger park, South Africa, 6-9 March 2012.
Hofmeyr GJ, for the Calcium and Pre-eclampsia (CAP) Study Group. Use of calcium and vitamin D for prevention of pre-eclampsia/eclampsia. USAID MCHIP Asia Regional Meeting on Interventions for Impact in Essential Obstetric and Newborn Care, Dhaka, Bangladesh May 3-6, 2012
Hofmeyr GJ, for the Calcium and Pre-eclampsia (CAP) Study Group. Low dose calcium supplementation for preventing pre-eclampsia: A systematic review and commentary. 32nd Conference on Priorities in Perinatal Care in Southern Africa, Mpekweni Beach Resort, 12-15 March 2013.
Hofmeyr GJ. Calcium and Pre-eclampsia, Nutrition meeting, Birchwood, Htel Johannesburg, 14 April 2013
Hofmeyr GJ. Evidence and global health: constraints and ethical dilemmas. African Cochrane indaba, Cape Town, 6-8 May 2013
Manyame S, Hofmeyr GJ. Pre-pregnancy calcium supplementation for the prevention of pre-eclampsia. African Cochrane indaba, Cape Town, 6-8 May 2013
Singata-Madliki M for the CAP study group. The effect of calcium supplementation on blood pressure in non-pregnant women with previous pre-eclampsia: an exploratory, randomized placebo controlled study (WHO Study A65750). 34th Priorities in Perinatal Care Conference, Champagne Sports Resort, Drakensberg, KZN 17-20 March 2015
Hofmeyr GJ on behalf of the CAP Study Group.Calcium Supplementation in Pre-eclampsia for preventing maternal mortality. International Conference on Maternal and Newborn Health Research – a KLE Centenary Eveny, Belgaum, India 5-6 March 2016.