Perinatal Outcomes Among Different Asian Groups With Gestational Diabetes Mellitus in Ontario: A Cohort Study.

OBJECTIVE:The aim of this study was to determine whether perinatal outcomes differ between Caucasian and Asian subgroups of women with gestational diabetes mellitus (GDM) through use of standard vs ethnicity-specific birthweight curves. METHODS:This retrospective cohort study included 537 women with GDM, within the ethnically diverse province of Ontario, Canada. Study outcomes included large-for-gestational-age (LGA) and small-for-gestational-age (SGA) birthweights in newborns of women from prevalent Asian ethnic groups compared with newborns of Caucasian women. Odds ratios were adjusted for maternal age, parity, prepregnancy body mass index, gestational weight gain and insulin use in pregnancy. RESULTS:Of the 537 women participing in the study, 228 (35.8%) were Caucasian, 109 (17.1%) South Asian, 141 (22.1%) East Asian and 59 (9.3%) Filipino. Using standard birthweight curves, compared with Caucasian women, the risk of LGA was lower among South Asian (adjusted odds ratio [aOR], 0.065; 95% confidence interval [CI], 0.01 to 0.49) and East Asian (aOR, 0.36; 95% CI, 0.14 to 0.95) women. The aOR for SGA was notably higher among South Asian women (aOR, 2.96; 95% CI, 1.24 to 7.09). Significant effects were not seen among Filipino women. Use of ethnicity-specific birthweight curves largely attenuated these associations, except for LGA in South Asian mothers (aOR, 0.27; 95% CI, 0.09 to 0.81). CONCLUSION:South Asian women with GDM are at lower risk of having an LGA newborn, even after accounting for maternal risk factors or the use of an ethnicity-specific birthweight curve.