Effective implementation strategies for delivering nutritional interventions through the health system to prevent malnutrition during pregnancy: A Systematic Review and Meta-analysis.

Malnutrition during pregnancy is a public health concern. Interventions implemented through the health sector can prevent maternal malnutrition. Our aim is to identify implementation strategies for delivering nutritional interventions through primary health care to prevent malnutrition in all its forms during pregnancy. We followed the Cochrane Handbook for Systematic Reviews and PRISMA guidelines. A search strategy was developed for five databases. The information was systematized using the Template for Intervention Description and Replication. Meta-analyses were performed using a random-effects model. We used the Risk of Bias and the Non-randomized Studies of Interventions tools, and the certainty of the evidence followed the GRADE guidelines. We included 51 studies conducted across high-, middle-, and low-income countries. Multiple micronutrient supplementation (MMS) was more effective than iron-folic acid (IFA) supplementation alone in improving hemoglobin levels and other anemia-related indicators, when initiated during the first or second trimester of pregnancy and delivered with in-person, individualized counseling and follow-up. Our meta-analysis confirmed that MMS improved maternal anemia compared to IFA with a moderate certainty of the evidence. Healthy eating counseling, physical activity, and weight gain monitoring, when combined, were effective in achieving weight gain when the interventions were guided by prenatal care protocols and included materials and resources to support. Our meta-analysis showed a non-significant reduction in excessive weight gain with very low certainty, no meaningful effect on low weight gain with low certainty, and a potentially meaningful increase in the likelihood of gaining weight within the recommended range with very low certainty. A coordinated package of health system-delivered interventions, including MMS, behavioral counseling, and monitoring of maternal weight gain, should be implemented within primary health care, beginning in the first or second trimester, to prevent all forms of malnutrition during pregnancy. Effective implementation strategies to provide these interventions can be adapted to local contexts. The protocol for this review was registered in PROSPERO with the ID CRD4202460299.