Introduction
Hypertensive disorders of pregnancy are a significant cause of severe morbidity, long-term disability and death among both mothers and their babies. Worldwide, they account for approximately 14% of all maternal deaths (1). Among the hypertensive disorders that complicate pregnancy, pre-eclampsia and eclampsia stand out as major causes of maternal and perinatal mortality and morbidity. The majority of deaths due to pre-eclampsia and eclampsia are avoidable through the provision of timely and effective care to the women presenting with these complications.
Improving care for women during pregnancy and around the time of childbirth to prevent and treat pre-eclampsia and eclampsia is a necessary step towards the achievement of the health targets of the Sustainable Development Goals (SDGs). Efforts to prevent and reduce morbidity and mortality due to these conditions can help address the profound inequities in maternal and perinatal health globally. To achieve this, healthcare providers, health managers, policy makers and other stakeholders need up-to-date and evidence-informed recommendations to guide clinical policies and practices.
In 2017, the Executive Guideline Steering Group (GSG) on WHO maternal and perinatal health recommendations prioritized the updating of the existing WHO recommendation on calcium supplementation during pregnancy in response to new evidence available on the effects of this intervention. This recommendation is a revalidation of the previous recommendation on calcium supplementation issued in 2016 in the WHO recommendations on antenatal care for a positive pregnancy experience (2).
Target audience
The primary audience of this recommendation includes health professionals who are responsible for developing national and local health protocols (particularly those related to pre-eclampsia and eclampsia) and those directly providing care to pregnant women and their newborns, including midwives, nurses, general medical practitioners, obstetricians, managers of maternal and child health programmes, and relevant staff in ministries of health, in all settings.
Guideline development methods
The update of this recommendation was guided by standardized operating procedures in accordance with the process described in the WHO handbook for guideline development. The recommendation was initially developed using this process, namely:
- (i)
identification of the priority question and critical outcomes;
- (ii)
retrieval of evidence;
- (iii)
assessment and synthesis of evidence;
- (iv)
formulation of the recommendation; and
- (v)
planning for the dissemination, implementation, impact evaluation and updating of the recommendations.
The scientific evidence supporting the recommendation was synthesized using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. An updated systematic review was used to prepare evidence profiles for the prioritized question. WHO convened an online meeting on 2 May 2018 where the Guideline Development Group (GDG) members reviewed, deliberated and achieved consensus on the strength and direction of the recommendation presented herein. Through a structured process, the GDG reviewed the balance between the desirable and undesirable effects and the overall certainty of supporting evidence, values and preferences of stakeholders, resource requirements and cost-effectiveness, acceptability, feasibility and equity. The GDG revalidated the WHO recommendation on calcium supplementation during pregnancy published in 2016 with minor revisions to the remarks and implementation considerations.
The recommendation
To ensure that the recommendation is correctly understood and applied in practice, guideline users may want to refer to the remarks, as well as to the evidence summary, including the considerations on implementation.
WHO recommendation on calcium supplementation during pregnancy for prevention of pre-eclampsia and its complications.
