The Relationship Between Sleep Quality, Glycemic Control, and Maternal-Neonatal Outcomes Among Women with Gestational Diabetes Mellitus in Tanzania

Background Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with significant maternal and neonatal risks. In low- and middle-income countries such as Tanzania, the rising burden of GDM is compounded by limited healthcare resources. Poor sleep quality has emerged as a modifiable factor linked to worsened insulin resistance and adverse pregnancy outcomes. However, data on sleep quality among women with GDM in sub-Saharan Africa remain scarce. This study aimed to assess sleep quality and its associations with glycemic control and maternal and neonatal outcomes among Tanzanian women with GDM. Methods A prospective longitudinal study was conducted in seven regional referral hospitals in Tanzania from August to October 2025. Convenience sampling enrolled pregnant women (18–45 years) diagnosed with GDM in the second trimester. The Pittsburgh Sleep Quality Index (PSQI) was administered at enrollment to evaluate participants’ sleep quality over the preceding month retrospectively. Demographic and glycemic data were collected at enrollment, while maternal-neonatal outcomes were extracted within 24 hours post-delivery. Data were analyzed using Stata 19.5 with descriptive statistics and linear and multivariate logistic regressions. Results A total of 360 women with GDM were enrolled in this study. The mean PSQI score was 10.8 ± 4.83, with poor sleep quality (PSQI > 5) highly prevalent at 91.4%. Higher education and being separated/widowed were associated with worse sleep. The overall glycemic control of participants was poor, with a mean fasting blood glucose of 13.6 ± 5.80 mmol/L. Poor sleep quality was independently associated with higher fasting blood glucose (β = 0.28, 95% CI: 0.20–0.36, P < 0.001). For maternal outcomes, each 1-point increase in PSQI score raised the risk of gestational hypertension (AOR = 1.11, 95% CI: 1.01–1.22, P = 0.036) and sepsis/infection (AOR = 1.14, 95% CI: 1.03–1.26, P < 0.001); no significant association was found between sleep quality and postpartum hemorrhage. For neonatal outcomes, each 1-point increase in PSQI raised the odds of neonatal hypoglycemia by 16% (AOR 1.16, 95% CI 1.07–1.27, P < 0.001). Conclusion Poor sleep quality is highly prevalent among Tanzanian women with GDM and is independently associated with poorer glycemic control, hypertensive disorders, maternal infection, and neonatal hypoglycemia. Integrating routine sleep screening and low-cost sleep interventions into antenatal GDM care may improve glycemic control and maternal-neonatal outcomes in resource-limited settings. Clinical Trial Number: Not applicable