Thirty percent of Indian newborns are low birth weight despite a large-scale national program providing nutritional supplements to pregnant women (UNICEF, 2008). Low birth weight and preterm delivery are highly correlated and continue to be among the major refractory causes of infant mortality and childhood morbidity (Gutbrod et al, 2000). Given these statistics, it is extremely important to determine the contributors to low birth weight in this population in order to design effective and appropriate interventions that will improve the health of Indian mothers and their babies. This proposal is for an investigation of the role of chronic parasitic infections (particularly giardia, entamoeba histolytica and helminthic infections) as contributors to low birth weight, preterm delivery and other birth outcomes in rural India. The hypotheses are that these infections cause or augment pregnancy outcomes such as iron deficiency anemia during the third trimester of pregnancy and also contribute to the high incidence of low birth weight and preterm babies in this population. The literature supports the contention that these pregnancy and birth outcomes may be the results of parasitic disruption of the digestive process and particularly maternal absorption of iron. The study design is a longitudinal cohort study that is being conducted in rural Andhra Pradesh, India, in collaboration with the Mediciti Institue of Medical Sciences. 1,000 women will be enrolled and followed from pre-pregnancy through the birth of their child up to the child's first month of life. Data collection will include biological specimens, data through questionnaires and anthropometric measures from both mother and infant. Women will be interviewed, measurements taken and samples collected at a registration visit before the woman is pregnant, during the first and third trimesters and within one month of the birth of the child.