© 2017 The Royal Society for Public Health Objective The aim of this prospective study was to estimate the prevalence and risk factors for maternal anaemia and low birth weight (LBW) in pregnant women living in Maharashtra state, India. Study design This is a prospective study. Methods Women between 3 and 5 months of pregnancy were recruited from 34 villages based in Maharashtra state. Baseline data collection, anthropometric measurements and blood investigations were performed. Participants were followed-up to record birth weight. Results In total, 303 women were eligible, and 287 (95%) provided data. 77% were anaemic, defined as haemoglobin less than 11.0 g/dl at the time of recruitment, with a mean corpuscular volume of 80.5 fl/cell (standard deviation: 7.22, range: 53.4–93.8). The increased risk of anaemia was seen in women with consanguineous marriages (odds ratio [OR]: 2.41, 95% confidence interval [CI] : 1.16–5.01, P = 0.01) after adjustment for potential confounding factors. Postdelivery data from full-term singleton live births demonstrated a 7% prevalence of LBW. Consanguineous marriage was a major risk factor for LBW (OR: 4.10, 95% CI: 1.25–13.41, P = 0.02). The presence of maternal anaemia during 3–5 months of pregnancy was associated with lower risk of LBW (unadjusted OR: 0.34, 95% CI: 0.13–0.92, P = 0.03). Conclusion About 30% of our study participants were in a consanguineous marriage, which was identified as a potentially avoidable risk factor for both anaemia and LBW.