Anisur Rahman of the Matlab Health Research Centre at the International Centre for Diarrhoeal Disease Research, Bangladesh (ICCDR,B) will lead a prospective cohort study of pregnant women, building on the ICDDR,B community-based surveillance site, to enroll more than 4,000 pregnant women over three years. His team will visit women monthly at their homes for early identification of pregnancy, followed by accurate gestational age dating by ultrasound and follow up throughout pregnancy and at delivery for collection of clinical data and specimens. The study includes standardized systems for documentation of complications of pregnancy and assessment of birth outcomes. Data and specimens will be used to advance innovative research into the causes of preterm birth and identify novel strategies for prevention.