Effects of preconception nutrition interventions on pregnancy and birth outcomes in South Asia: a systematic review

Undernutrition amongst reproductive age women, low birth weight, small for gestational age and preterm birth present significant health burdens in South Asia which interventions in pregnancy alone have not resolved. Effectiveness of preconception nutrition interventions is not well-documented. This systematic review summarises evidence on the effect of preconception nutrition interventions on pregnancy and birth outcomes in South Asia. We found highly heterogeneous evidence across four micronutrient supplementation, two food supplementation, and three complex interventions trials. Preconception micronutrient supplementation alone did not affect birth size, but food supplementation was effective with and without multiple micronutrients, especially when initiated at least 90 days before conception. Combined health, nutrition, psychosocial care, and WaSH interventions addressing determinants at multiple levels were most effective. However intensive delivery by project employees poses problems for scale-up. More robust South Asian preconception intervention trials to identify scalable interventions that are effective in real-world delivery settings are needed. Funding: UNICEF Regional Office for South Asia contract number 43384734.