Iron/folic acid supplementation during pregnancy prevents neonatal and under-five mortality in Pakistan: propensity score matched sample from two Pakistan Demographic and Health Surveys

Abstract

Background: Several epidemiological studies from low- and middle-income countries have reported a protective effect of maternal antenatal iron/folic acid (IFA) on childhood mortality.

Objective: The current study aimed to evaluate the effect of maternal antenatal IFA supplementation on childhood mortality in Pakistan.

Design: A propensity score-matched sample of 8,512 infants live-born within the 5 years prior to interview was selected from the pooled data of two Pakistan Demographic and Health Surveys (2006/07 and 2012/13). The primary outcomes were childhood mortality indicators and the main exposure variable was maternal antenatal IFA supplementation. Post-matched analyses used Cox proportional hazards regression and adjusted for 16 potential confounders.

Results: Maternal antenatal IFA supplementation significantly reduced the adjusted risk of death on day 0 by 33% [adjusted hazard ratio (aHR)=0.67, 95% confidence interval (95% CI) 0.48-0.94], during the neonatal period by 29% (aHR=0.71, 95% CI 0.57-0.88), and for under-fives by 27% (aHR=0.73, 95% CI 0.60-0.89). When IFA was initiated in the first 4 months of pregnancy, the adjusted risk of neonatal and under-five deaths was significantly reduced by 35 and 33%, respectively. Twenty percent of under-five deaths were attributable to non-initiation of IFA in the first 4 months of pregnancy. With universal initiation of IFA in the first 4 months of pregnancy, 80,300 under-five deaths could be prevented annually in Pakistan.

Conclusions: Maternal antenatal IFA supplementation significantly reduced neonatal and under-five deaths in Pakistan. Earlier initiation of supplements in pregnancy was associated with a greater prevention of neonatal and under-five deaths.

Keywords: antenatal care; iron/folic acid supplements; mortality; neonatal; propensity score; under-five.

Fig. 1

Process of selection of most recent live births in the 5 years prior to interview in two Demographic and Health Surveys based on propensity score matching in Pakistan, 2002–2012. †33 cases were excluded.

Fig. 2

Effect of maternal antenatal iron/folic acid supplementation on childhood mortality indicators of most recent live births in the 5 years prior to interview in Pakistan, 2002–2012: results of multivariate Cox proportional hazards regression analyses. Seventy-six missing values were excluded from the analysis. †Adjusted for province of residence, pooled household wealth index, average coverage of BCG vaccination against tuberculosis (for mortality in neonatal and infant period), average coverage of measles vaccination (for under-five mortality), paternal level of education attained, paternal working status, maternal desire for pregnancy, sex of the child, birth rank and birth interval, maternal perception of birth size, timing of initiation of breastfeeding, number of antenatal care visits, place of delivery, delivery assistance, mode of delivery, and year of birth.

Fig. 3

Effect of timing of initiation of maternal antenatal iron/folic acid supplementation on childhood mortality indicators of most recent live births in the 5 years prior to interview in Pakistan 2002–2012: results of multivariate Cox proportional hazards regression analyses. Five hundred twenty-one missing values were excluded from the analysis. †Adjusted for province, pooled household wealth index, average coverage of BCG vaccination against tuberculosis (for mortality in neonatal and infant period), average coverage of measles vaccination (for under-five mortality), paternal level of education attained, paternal working status, maternal desire for pregnancy, sex of the child, birth rank and birth interval, maternal perception of birth size, timing of initiation of breastfeeding, number of antenatal care visits, place of delivery, delivery assistance, mode of delivery, and year of birth.

Fig. 4

Effect of combination of maternal antenatal iron/folic acid supplementation and other antenatal care services used on childhood mortality indicators of most recent live births in the 5 years prior to interview in Pakistan, 2002–2012: results of multivariate Cox proportional hazards regression analyses. Seventy-six missing values were excluded from the analysis. †Adjusted for province of residence, pooled household wealth index, average coverage of BCG vaccination against tuberculosis (for mortality in neonatal and infant period), average coverage of measles vaccination (for under-five mortality), paternal level of education attained, paternal working status, maternal desire for pregnancy, sex of the child, birth rank and birth interval, maternal perception of birth size, timing of initiation of breastfeeding, number of antenatal care visits, place of delivery, delivery assistance, mode of delivery, and year of birth.

Fig. 5

Plot of adjusted cumulative mortality for under-five children by (a) maternal antenatal iron/folic acid supplementation; (b) timing of initiation of maternal antenatal iron/folic acid supplementation. Results of the Cox proportional hazards regression analysis were adjusted for province, pooled household wealth index, average coverage of BCG vaccination against tuberculosis (for mortality in neonatal and infant period), average coverage of measles vaccination (for under-five mortality), paternal level of education attained, paternal working status, maternal desire for pregnancy, sex of the child, birth rank and birth interval, maternal perception of birth size, timing of initiation of breastfeeding, number of antenatal care visits, place of delivery, delivery assistance, mode of delivery, and year of birth.