GDM prevalence, risk factors differ for ethnic Chinese women living in Singapore vs Shanghai

The prevalence of gestational diabetes mellitus (GDM) differs between ethnic Chinese women living in Shanghai and Singapore, according to a recent study. Moreover, though some risk factors are shared, women from both locations are susceptible to them to varying degrees.

According to the researchers, these differences across locations “might be due to heterogeneity of GDM reflected in diagnostic criteria as well as in unmeasured genetic, lifestyle, and environmental factors.”

Accessing the Shanghai Birth Cohort (SBC) and Growing Up in Singapore Towards Health Outcomes (GUSTO), the researchers retrieved relevant data of 734 and 677 women, respectively. Participants were also followed-up at baseline and during pregnancy, where they were given questionnaires to assess sociodemographic factors, lifestyle, and obstetric and medical histories.

GDM was assessed through an oral glucose tolerance test and blood profile measurements. The 1999 World Health Organization (WHO) criteria and the International Association of Diabetes and Pregnancy Study Groups (IADPSG) guidelines were used to diagnose GDM.

According to the WHO criteria, 20.8 percent of women from the GUSTO cohort had GDM, significantly more than the 16.6-percent prevalence in SBC (p=0.046). However, the opposite was true when following the IADPSG classification, which detected GDM in 12.0 percent and 14.3 percent of the respective cohorts. [BMC Pregnancy Childbirth 2021;21:566]

Similarly, both cohorts differed in terms of risk factors. For instance, the effect of a family history of hypertension was significantly stronger among the GUSTO vs SDC women (odds ratio [OR], 0.67 vs 0.223, respectively; p=0.016). In contrast, SDC participants were more susceptible to the effects of alcohol consumption than their GUSTO counterparts (OR, 8.8 vs 0.73; p<0.001).

When using the IADPSG criteria, the effect of alcohol consumption on GDM risk remained significantly stronger in SDC participants (OR, 12.0 vs 0.99; p<0.001), and a similar trend was detected for family history of diabetes (OR, 1.8 vs 0.67; p=0.02). In contrast, having had GDM in a previous pregnancy exerted a stronger impact on GUSTO women (OR, 7.7 vs 2.5; p<0.001). The differential effect of family hypertension history was attenuated.

In both cohorts, prepregnancy body mass index (BMI) had comparable effects on GDM risk when using both diagnostic criteria.

“The findings of the study help to provide different clinical recommendations for GDM prevention in Chinese women from China and Singapore,” the researchers said. “Native Chinese women residing in China who have family history of diabetes and/or are overweight can also be identified as a high-risk group and followed more closely throughout their pregnancy for timely interventions against GDM.”

On the other hand, some recommendations may be shared across geographical locations. “Women who are intending to start a family can be advised to conceive at a younger age and to control their prepregnancy weight,” the researchers noted.