ORIGINAL ARTICLE The effect of fish and x-3 LCPUFA intake on low birth weight in Indian pregnant women S Muthayya 1 , P Dwarkanath 1 , T Thomas 1 , S Ramprakash 1 , R Mehra 2 , A Mhaskar 3 , R Mhaskar 3 , A Thomas 3 , S Bhat 4 , M Vaz 1 and AV Kurpad 1 1 Division of Nutrition, Maternal and Child Health Unit, St John’s Research Institute, St John’s National Academy of Health Sciences, Bangalore, India; 2 GlaxoSmithKline Consumer Healthcare Ltd, Gurgaon, India; 3 Department of Obstetrics and Gynecology, St John’s Medical College Hospital, St John’s National Academy of Health Sciences, Bangalore, India and 4 Department of Pediatrics, St John’s Medical College Hospital, St John’s National Academy of Health Sciences, Bangalore, India Background: Inadequate consumption of fish could be a risk factor for low birth weight (LBW). This study assessed fish intake and o-3 LCPUFA intake and status for their association with LBW in a cohort of urban, south Indian pregnant women. Subjects/methods: In a prospective cohort study, data on maternal fish intake and o-3 LCPUFA intake and status of 676 women were obtained at baseline (first trimester), the second and third trimesters of pregnancy. Infant birth weight was measured immediately following hospital delivery. The dropout rate was 7.6%. Results: Fifty-six percent of the study women consumed fish with low daily median intakes (3.4, 4.1 and 3.8 g day 1 at the three trimesters, respectively). Consequently, the median intakes of EPA and DHA during pregnancy were also low at 2.1 and 10.1 mg day 1 , respectively. EPA and DHA intakes were associated with their status in erythrocyte membrane phospholipids during pregnancy (r ¼ 0.40 and 0.36, r ¼ 0.34 and 0.32 and r ¼ 0.37 and 0.41, at the three trimesters, respectively, all Po0.001). Women who did not eat fish during the third trimester had a significantly higher risk of LBW (OR: 2.49, P ¼ 0.019). Similarly, low EPA intake during the third trimester had an association with a higher risk of LBW (OR: 2.75, P ¼ 0.011). Conclusions: Among low fish-eating pregnant women, fish intake in the third trimester was closely associated with birth weight. Supplementation with o-3 LCPUFA during pregnancy may have important implications for fetal development in India. European Journal of Clinical Nutrition (2009) 63, 340–346; doi:10.1038/sj.ejcn.1602933; published online 24 October 2007 Keywords: low birth weight; pregnancy; fish; o-3 fatty acids; DHA; India Introduction Long-chain o-3 polyunsaturated fatty acids (o-3 LCPUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), play an important role during pregnancy as they are important structural constituents of the highly specia- lized membrane lipids of the developing brain and central nervous system. Since the fetus depends primarily on placental transfer of these fatty acids, it is important that maternal LCPUFA status and supply are adequate to meet fetal requirements (Innis, 1991). There is evidence that a habitually higher intake of fish, a rich source of o-3 LCPUFA, improves birth weight. In the early 1990s, positive associations between maternal fish intake during pregnancy and birth size were found in Danish fish-eating communities (Olsen et al., 1990, 1993). More recently, in the same population, a strong negative associa- tion of fish intake with the risk of both low birth weight (LBW) and preterm delivery was reported (Olsen and Secher, 2002). However, these were habitual fish-eating commu- nities, and the question remained as to whether such effects could be observed in developing country populations with Received 8 August 2007; revised 23 August 2007; accepted 29 August 2007; published online 24 October 2007 Correspondence: Dr S Muthayya, Division of Nutrition, Maternal and Child Health Unit, St John’s Research Institute, St John’s National Academy of Health Sciences, Koramangala, Bangalore, Karnataka 560034, India. E-mail: sumithra@iphcr.res.in Guarantor: S Muthayya. Contributors: SM wrote the first draft of the manuscript and was involved in study design and implementation and data analysis. PD was involved in study design, implementation and data entry and writing of the manuscript. TT was involved in data analysis and writing of the manuscript. SR was involved in data entry, biochemical analyses and writing of the manuscript. AVK was involved in study design, data analysis and writing of the manuscript. RM and MV were involved in data interpretation and writing of the manuscript. AM, RM, AT and SB provided study subjects and facilities for this collaborative research. European Journal of Clinical Nutrition (2009) 63, 340–346 & 2009 Macmillan Publishers Limited All rights reserved 0954-3007/09 $32.00 www.nature.com/ejcn