 Eligibility: In order to maximise the generalisability of the results of this study, the criteria for eligibility will be broad and inclusive. All pregnancies that occur within the geographic boundaries of the participating villages, which result in a live born infants, will be eligible for recruitment. This will include multiple births, those with congenital anomalies, and those born early or with low birth weight. Provision of informed consent will be the only eligibility criterion in addition to geographic eligibility. 