The study design was a population-based prospective cohort study conducted 3,522 pregnancies were initially included in the year 2000 from 4 districts across Thailand, The district in the central part, the south, and the northeast are all rural. The fourth district is in the northern part of Thailand data from 3,501 cases with maternal ages and giving livebirths were analyzed. Information was collected from interviews and maternal health records. Ethical ap proval was obtained from the study’s Ethic Committees. . It is a mix of semi-urban and rural areas. The income levels are medium to low in all four districts. The main