Guideline1
Executive summary Calcium supplementation in pregnant women
Purpose of the guideline: Poor maternal and newborn health and nutrition remain significant contributors to the burden of disease and mortality. Calcium supplementation has the potential to reduce adverse gestational outcomes, in particular by decreasing the risk of developing hypertensive disorders during pregnancy, which are associated with a significant number of maternal deaths and considerable risk of preterm birth, the leading cause of early neonatal and infant mortality. Member States have requested guidance from the World Health Organization (WHO) on the efficacy and safety of calcium supplementation in pregnant women as a public health strategy, in support of their efforts to achieve the Millennium Development Goals and the global targets set in the maternal, infant and child nutrition comprehensive implementation plan. The guideline is intended for a wide audience including policy-makers, their expert advisers, and technical and programme staff at organizations involved in the design, implementation and scaling-up of nutrition actions for public health.
Guideline development methodology: WHO developed the present evidence-informed recommendations using the procedures outlined in the WHO handbook for guideline development. The steps in this process included: (i) identification of priority questions and outcomes; (ii) retrieval of the evidence; (iii) assessment and synthesis of the evidence; (iv) formulation of recommendations, including research priorities; and (v) planning for dissemination, implementation, impact evaluation and updating of the guideline. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was followed to prepare evidence profiles related to preselected topics, based on up-to-date systematic reviews. The guideline development group for nutrition interventions, the Nutrition Guidance Advisory Group, consisted of content experts, methodologists, representatives of stakeholders, consumers and guideline users. These experts participated in two WHO technical consultations concerning this guideline, held in 2011 in Geneva, Switzerland, and Washington DC, United States of America. Members of the External Experts and Stakeholders Panel were identified through a public call for comments, and this panel was involved throughout the guideline development process.
Available evidence: Two Cochrane systematic reviews investigated whether calcium supplementation on a daily basis during pregnancy safely improved maternal and infant outcomes. The findings revealed that this intervention significantly reduced the risk of pre-eclampsia and high blood pressure (with or without proteinuria). Women who received calcium supplements had a significantly higher risk of developing HELLP (haemolysis, elevated liver enzymes, and low platelet count) syndrome, a rare adverse event associated with severe pre-eclampsia. Calcium supplementation had no effects on the risk of developing eclampsia or maternal death or maternal admission to the intensive care unit.