Preeclampsia is a multisystemic pathology affecting of pregnant women. It is defined as high blood pressure, often appearing after 20 weeks of gestation, and is associated with organ dysfunction such as nephropathy (kidney damage), hepatopathy (liver damage), and others. Currently, the progression of this disease can only be halted by induced delivery or Cesarean section.
This pathology is directly responsible for approximately 42,000 maternal deaths and more than 500,000 perinatal deaths (stillbirths or neonatal deaths) annually, necessitating the development of an effective prevention plan.
To address this clinical problem, the Cochrane Systematic Review assessed data from 10 Randomized Controlled Trials (RCTs). The analysis involved 37,504 pregnant women. The main objective of the study was to determine whether routine calcium supplementation during pregnancy could reduce or prevent the risk of preeclampsia development.
Hypothesis and Evidence Shift
The old hypothesis was based on the idea that calcium supplements could help reduce vascular tone (vasodilation), improve cellular signaling, and decrease heightened uterine contractions.
Early Data: Observational studies suggested that the incidence of preeclampsia was higher in populations with a low-calcium diet. Small RCTs conducted in the 1980s initially appeared promising.
Latest Evidence: More extensive, multicenter studies failed to confirm this protective effect, casting doubt on existing clinical recommendations.
The World Health Organization (WHO) previously recommended that women with low dietary calcium intake should receive grams of calcium daily.
Researchers checked databases until January 2025 and included only RCTs with high methodological reliability in the review (specifically, those registered after 2010 and checked by TRACT criteria). As a result of this rigorous approach, 20 studies were removed from the 2018 review due to changes in criteria, methodological flaws, or a high risk of bias.
Scope of the Analysis:
Calcium vs. Placebo: 8 trials (15,504 women).
Low Dose vs. High Dose: 2 large-scale trials (22,000 women).
The study results show that the patient’s baseline calcium level or other individual risk factors do not influence the preventive outcomes. Therefore, attention should be fully directed toward more effective and targeted interventions:
Targeted Prevention: Prescribing low-dose aspirin in high-risk groups (e.g., those with a history of previous preeclampsia) and continuous, strict monitoring of hypertension.
Fundamental Research: The focus should be on studying the probable causes of preeclampsia and diagnosing the disease before the 12th week of gestation, allowing for early intervention.
Global Influence
WHO Guidelines: The World Health Organization’s guidelines regarding the routine use of calcium need immediate revision.
Investment in Research: Investment in research conducted on diverse populations must be increased to determine real ways to prevent preeclampsia.
The real prevention of preeclampsia is the only way to reduce maternal and perinatal mortality.
Source: Cochrane
