Association between diabetes mellitus type 2 and cervical insufficiency: a retrospective case-control study

Cervical insufficiency (CI) is the inability of the cervix to retain the pregnancy leading to a high risk of second-trimester fetal loss or extremely preterm birth. There is no current evidence of any association between CI and maternal abnormal glucose tolerance (AGT). The aim of this study was to investigate a potential association between CI and maternal AGT.

This retrospective case-control study was conducted by recruiting all women referred to the Department of Women and Child Health of the Research Hospital Gemelli IRCCS of Rome, from 2016 to 2023 for CI. Cases were chosen among patients with an ultrasound finding of short cervical length (<25 mm) before 24 weeks of gestation, with at least one second trimester fetal loss for CI. Healthy women admitted for delivery at term with at least one previous normal pregnancy and no previous fetal losses or preterm deliveries were enrolled as controls. All women enrolled in this study, both cases and controls, were monthly evaluated for fasting glucose levels in pregnancy and underwent oral glucose tolerance test (OGTT) for gestational diabetes mellitus (GDM) screening at 24-28 weeks of gestation. Prevalence of AGT was compared among cases and controls and the finding of AGT was associated with maternal-neonatal outcomes among the study population. Cases and controls were compared using parametric or non-parametric tests, as appropriate. Multivariable logistic regression analyses were performed to account for potential confounders, such as maternal age and BMI.

Women with CI showed a significantly higher prevalence of diabetes mellitus type 2 (DM2) (11/96 vs. 1/96, p < 0.01), vaginal/cervical infections (45/96 vs. 22/96, p < 0.001), and chorioamnionitis (28/96 vs. 0/96, p < 0.0001) compared to controls.

Pregnant women with DM2 were eightfold more likely to have CI compared to pregnant women with normal glucose tolerance.