Fasting during pregnancy and gestational diabetes mellitus risk: Kuwait birth cohort study

Background

Ramadan fasting, the practice of abstaining from eating and drinking from sunrise to sunset, is a common practice among adult Muslims worldwide. The scientific literature lacks consistent evidence on the effects of Ramadan fasting on pregnancy outcomes. In this study, we sought to assess associations between fasting during pregnancy and gestational diabetes mellitus (GDM) risk.

Methods

Pregnant women in their second or third trimester of pregnancy were enrolled in the Kuwait Birth Cohort study. Detailed information on fasting practices, nutritional biomarkers, and sociodemographic factors was available for analysis. GDM status was ascertained according to international guidelines. Adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) were estimated using modified Poisson regression models with robust variance estimation.

Results

Data from 1,087 pregnant women (mean age: 31.4±5.3 years) were analyzed. A total of 581 (53.5%) women reported any fasting during their current pregnancy, with 212 (19.5%), 273 (25.1%), and 110 (10.1%) women reporting fasting during the first, second, and third trimesters of pregnancy, respectively. The incidence of GDM (17.2% in the total sample) among those who reported any fasting did not differ significantly from those who reported no fasting (16.2% vs. 18.2%, p = 0.388). After adjusting for potential confounders, fasting in the first trimester was not associated with GDM risk compared to no fasting (aRR: 0.95, 95% CI: 0.67–1.35). Moreover, although statistically not significant, fasting in the second (aRR: 0.79, 95% CI: 0.56–1.12) and third (aRR: 0.65, 95% CI: 0.36–1.15) trimesters compared to no fasting showed a potential trend toward reduced GDM risk.

Conclusions

Fasting during later stages of pregnancy might reduce the risk of GDM. Nonetheless, more adequately powered studies are needed to corroborate our findings and guide evidence-based clinical recommendations for antenatal care.

Key messages

• Ramadan fasting in early pregnancy is not associated with GDM. Notably, fasting in the second and third trimesters shows a potential trend toward reduced GDM risk.

• Though non-significant, the GDM risk reduction linked to late-pregnancy fasting is clinically important. Larger studies must corroborate and translate this into evidence-based antenatal care.