Preeclampsia, the development of high blood pressure and protein in the urine during pregnancy and its more severe complications such as eclampsia, can threaten the lives of both mother and child. While there is no therapy to prevent preeclampsia, a link to calcium deficiency has been suggested. In a study published in the March 2006 issue of the American Journal of Obstetrics and Gynecology, researchers across the globe, under the auspices of the World Health Organization (WHO), investigated whether a calcium supplement could reduce the complications and mortality from this condition.
Over 8300 women with low dietary calcium (<600 mg/day, about half of that recommended during pregnancy) were selected for the study. The subjects were randomly divided into two groups that had similar gestational ages, demographic characteristics, and normal blood pressures before treatment started. Half were given 1.5g of a calcium supplement per day and half received a placebo.
While the incidence of preeclampsia was not statistically different in the supplemented women, eclampsia, other severe complications and severe gestational hypertension were significantly lower. Overall, the "severe preeclamptic complications index" and the "severe maternal morbidity and mortality index," including all severe conditions, were also reduced with calcium.
Preterm and early preterm delivery (<32 weeks) tended to be reduced among women <20 years of age who were at highest risk for low calcium and complications. It is very important to note that neonatal mortality was also lower in the calcium group.
This multicenter, randomized, placebo-controlled, double-blind trial was performed at antenatal care centers located in Rosario, Argentina; Assiut, Egypt; Nagpur and Vellore, India; Lima, Peru; East London and Johannesburg, South Africa; and Ho Chi Minh City, Vietnam. These centers are part of the WHO Maternal and Perinatal Research Network, each having extensive clinical trial experience.
Writing in the article, Jose Villar, MD, states, "This large randomized trial in populations with low calcium intake demonstrates that while supplementation with 1.5 gm calcium/day did not result in a statistically significant decrease in the overall incidence of preeclampsia, calcium significantly decreased the risk of its more serious complications, including maternal and severe neonatal morbidity and mortality, as well as preterm delivery, the latter among young women."
"WHO Randomized Trial of Calcium Supplementation Among Low Calcium Intake Pregnant Women" by Jose Villar, MD; Hany Abdel-Aleem, MD; Mario Merialdi, MD; Matthews Mathai, MD; Mohamed Ali, PhD; Nelly Zavaleta, MD; Manorama Purwar; MD; Justus Hofmeyr, MD; Nguyen thi Nhu Ngoc, MD; Liana Camp¨®donico, MSc; Sihem Landoulsi, MSc; Guillermo Carroli, MD and Marshall Lindheimer, MD, on behalf of the WHO Calcium Supplementation for the Prevention of Preeclampsia Trial Group, American Journal of Obstetrics and Gynecology, March 2006, Volume 194, Issue 3.