Background
Women with gestational diabetes mellitus (GDM) have an increased risk of adverse pregnancy outcomes. This study examined predictors for GDM recurrence at their next pregnancy in a multi‐ethnic population. Clinical outcomes of women with GDM at the index as well as the subsequent pregnancies were also compared.

Materials and Methods
A retrospective review of women with GDM (between 2008 and 2016) who had a subsequent pregnancy at a tertiary institution was conducted. The clinical characteristics of both pregnancies were documented.

Results
Among 3587 singleton pregnancies complicated by GDM, 501 fell pregnant again and 367 (73.1%) developed GDM in their subsequent pregnancies. Subsequent pregnancies had higher birthweight (3426 ± 563 vs 3290 ± 506 g, P < 0.001) but the rate of pre‐eclampsia was lower (1.0% vs 4.2%, P = 0.003). Univariate analysis showed that older age, prior history of GDM, pre‐pregnant body mass index (BMI), two‐hour glucose level on glucose tolerance test (GTT), insulin requirement at the index pregnancy, and inter‐pregnancy weight gain were associated with recurrent GDM. Using stepwise logistic regression analysis, pre‐pregnant BMI, glucose levels on GTT at index pregnancy and inter‐pregnancy weight gain were independent predictors for recurrent GDM. The odds ratios for recurrent GDM among those who gained more than 8 kg were 20.5 (5.0–84.5), compared with those who lost over 5 kg between the two pregnancies. GDM recurrence rate was independent of ethnic backgrounds. Conclusion Women with GDM have high risk of GDM recurrence at their next pregnancy. Inter‐pregnancy weight gain is a strong predictor of recurrent GDM, and strategies to help women lose weight post‐partum may be invaluable.