The effect of folic acid, protein energy and multiple micronutrient supplements in pregnancy on stillbirths

Background: Pregnancy is a state of increased requirement of macro- and micronutrients, and malnourishment or inadequate dietary intake before and during pregnancy, can lead to adverse perinatal outcomes including stillbirths. Many nutritional interventions have been proposed during pregnancy according to the nutritional status of the mother and baseline risk factors for different gestational disorders. In this paper, we have reviewed three nutritional interventions including peri-conceptional folic acid supplementation, balanced protein energy supplementation and multiple micronutrients supplementation during pregnancy. This paper is a part of a series to estimate the effect of interventions on stillbirths for input to Live Saved Tool (LiST) model. Methods: We systematically reviewed all published literature to identify studies evaluating effectiveness of peri-conceptional folic acid supplementation in reducing neural tube defects (NTD), related stillbirths and balanced protein energy and multiple micronutrients supplementation during pregnancy in reducing all-cause stillbirths. The primary outcome was stillbirths. Meta-analyses were generated where data were available from more than one study. Recommendations were made for the Lives Saved Tool (LiST) model based on rules developed by the Child Health Epidemiology Reference Group (CHERG). Results: There were 18 studies that addressed peri-conceptional folic acid supplementation for prevention of neural tube defects (NTDs). Out of these, 7 studies addressed folic acid supplementation while 11 studies evaluated effect of folic acid fortification. Pooled results from 11 fortification studies showed that it reduces primary incidence of NTDs by 41 % [Relative risk (RR) 0.59; 95 % confidence interval (CI) 0.52-0.68]. This estimate has been recommended for inclusion in the LiST as proxy for reduction in stillbirths. Pooled results from three studies considered to be of low quality and suggest that balanced protein energy supplementation during pregnancy could lead to a reduction of 45% in stillbirths [RR 0.55, 95 % CI 0.31-0.97]. While promising, the intervention needs more effectiveness studies before inclusion in any programs. Pooled results from 13 studies evaluating role of multiple micronutrients supplementation during pregnancy showed no significant effect in reducing stillbirths [RR = 0.98; 95% CI: 0.88 - 1.10] or perinatal mortality [RR = 1.07; 95% CI: 0.92 - 1.25; random model]. No recommendations have been made for this intervention for inclusion in the LiST model. Conclusions: Peri-conceptional folic acid supplementation reduces stillbirths due to NTDs by approximately 41%, a point estimate recommended for inclusion in LiST.