Demographic characteristics
Maternal and infant demographics are described in table 1. BMI and hip circumference were higher among European women (p<0.01), although there were no differences in waist circumference or waist-hip ratio between ethnic groups. Only 1.5% and 2.9% of Indian women smoked or drank alcohol at 15±1 weeks gestation, compared with 11.1% and 10.9% among European women, respectively (p <0.01 for each).
Women of Indian ethnicity were more likely to have been treated for anaemia before the index pregnancy (19.6% vs 12.9%, p=0.02) and have anaemia at 15±1 weeks\(\ \)gestation (haemoglobin <110 g/L; 6.5% vs 1.8%, p<0.01). A vegetarian diet was also significantly more likely in Indian (15.2%) compared with European (1.5%, p<0.01). There was a 1 g/L difference in haemoglobin levels between non-vegetarian and vegetarian women of Indian ethnicity (124.2 vs 123.2 g/L, p=0.67). Almost double the number of Indian mothers compared with European reported having polycystic ovarian syndrome (11.6% vs 6.3%, p=0.01). However, there were no differences in history of infertility or fertility treatment to conceive the index pregnancy. Finally, Indian women were more often diagnosed with GDM (8.7% vs 2.3%, p<0.01), while rates of hypertensive disorders diagnosed during pregnancy were not significantly different. For infants, mean birthweight was lower among those born to Indian mothers (3,065g), compared with those born to European (3,412g, p<0.01 adjusted for gestational age alone), but there was no difference in customised birthweight centiles. Although European women had a higher mean gestational age at birth, there was no difference in the prevalence of preterm birth <37 weeks gestation (p=0.38).