A Retrospective Analysis of the Outcomes of Pregnancies in Women Affected by Overt Diabetes Compared to Women Affected by Pre-Existing Type 2 Diabetes

Abstract

Background: Pregestational diabetes mellitus, if not well controlled, determines maternal and fetal complications. According to the new diagnostic criteria for gestational diabetes, the diagnosis of diabetes mellitus can also occur in early pregnancy (overt diabetes). Aim: This study aims to determine pregnancy outcomes in women with overt diabetes compared to women with pre-existing type 2 diabetes. Methods: In this retrospective study, we selected women with pre-existing type 2 and overt diabetes who had at least one pregnancy in the 2010–2022 period at the Diabetic Care Unit of Padova. Results: We analyzed 83 pregnancies, and overt diabetes was diagnosed in 18 pregnancies. In total, 95.5% of patients with overt diabetes and 48% of T2DM patients were immigrants (p < 0.143). No patients with overt diabetes planned their pregnancy, while pregnancy was planned in 26.3% of patients with pre-exiting type 2 diabetes (p < 0.05). Periconception and first-trimester glycemic control were the worst in patients with overt diabetes (HbA1c 9.7 ± 3.1% vs. 7.3% ± 2.3%, p < 0.044, at first visit; 8.1 ± 1.9% and 7.0 ± 1.6%, p < 0.037 in the first trimester) with respect to patients with pre-existing type 2 diabetes. As for maternal outcomes, 16.6% of pregnancies ended in miscarriage, and 5.5% of women developed gestational hypertension; as for newborn outcomes, 16.6% of newborns were LGA, and 11.1% were affected by congenital anomalies without any significant difference with respect to women with pre-existing type 2 diabetes. The high rate of congenital malformations in pregnancies of women with overt diabetes is probably a result of the poor, metabolic control observed during the periconception period when the organogenesis of the fetus takes place. Conclusions: It is essential to utilize procedures for diabetes screening in women of childbearing age not only at the beginning of the pregnancy, but also during the preconception phase or the postmenarcheal period when strong risk factors for diabetes onset are present, such as a high BMI, glycemic disorders, and those who fall under high-risk ethnicity categories.