Factors predicting recurrence of gestational diabetes in a high-risk multi-ethnic population

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.