PT - JOURNAL ARTICLE AU - Michael A Zulyniak AU - Russell J de Souza AU - Mateen Shaikh AU - Dipika Desai AU - Diana L Lefebvre AU - Milan Gupta AU - Julie Wilson AU - Gita Wahi AU - Padmaja Subbarao AU - Allan B Becker AU - Piush Mandhane AU - Stuart E Turvey AU - Joseph Beyene AU - Stephanie Atkinson AU - Katherine M Morrison AU - Sarah McDonald AU - Koon K Teo AU - Malcolm R Sears AU - Sonia S Anand ED - , TI - Does the impact of a plant-based diet during pregnancy on birth weight differ by ethnicity? A dietary pattern analysis from a prospective Canadian birth cohort alliance AID - 10.1136/bmjopen-2017-017753 DP - 2017 Nov 01 TA - BMJ Open PG - e017753 VI - 7 IP - 11 4099 - http://bmjopen.bmj.com/content/7/11/e017753.short 4100 - http://bmjopen.bmj.com/content/7/11/e017753.full SO - BMJ Open2017 Nov 01; 7 AB - Objective Birth weight is an indicator of newborn health and a strong predictor of health outcomes in later life. Significant variation in diet during pregnancy between ethnic groups in high-income countries provides an ideal opportunity to investigate the influence of maternal diet on birth weight.Setting Four multiethnic birth cohorts based in Canada (the NutriGen Alliance).Participants 3997 full-term mother–infant pairs of diverse ethnic groups who had principal component analysis-derived diet pattern scores—plant-based, Western and health-conscious—and birth weight data.Results No associations were identified between the Western and health-conscious diet patterns and birth weight; however, the plant-based dietary pattern was inversely associated with birth weight (β=−67.6 g per 1-unit increase; P<0.001), and an interaction with non-white ethnicity and birth weight was observed. Ethnically stratified analyses demonstrated that among white Europeans, maternal consumption of a plant-based diet associated with lower birth weight (β=−65.9 g per 1-unit increase; P<0.001), increased risk of small-for-gestational age (SGA; OR=1.46; 95% CI 1.08 to 1.54;P=0.005) and reduced risk of large-for-gestational age (LGA; OR=0.71; 95% CI 0.53 to 0.95;P=0.02). Among South Asians, maternal consumption of a plant-based diet associated with a higher birth weight (β=+40.5 g per 1-unit increase; P=0.01), partially explained by cooked vegetable consumption.Conclusions Maternal consumption of a plant-based diet during pregnancy is associated with birth weight. Among white Europeans, a plant-based diet is associated with lower birth weight, reduced odds of an infant born LGA and increased odds of SGA, whereas among South Asians living in Canada, a plant-based diet is associated with increased birth weight.