Fetal growth trajectory in type 1 pregestational diabetes (PGDM) - an ultrasound study

Growth disorders are frequent in diabetic pregnancies. However, they are difficult to predict and capture early during pregnancy. These newborns are at risk of obesity, diabetes, and cardiovascular disease. While developing, fetal growth abnormalities are typically progressive. Therefore, capturing the earliest moment when they emerge is essential to guide subsequent obstetric management.

We aimed to analyze fetal ultrasound growth trajectories in type 1 diabetics. Moreover, we aimed to establish time points when first ultrasound manifestations of fetal growth abnormalities appear and to identify factors that affect fetal growth in women with diabetes. We collected clinical and ultrasound data from 200 patients with PGDM managed in the third-referential centre for diabetes in pregnancy. During every visit, patients underwent an ultrasound examination according to a standard protocol giving 1072 ultrasound scan's records. Every ultrasound consisted of fetal weight estimation, according to the Hadlock 3 formula. Retrospectively patients were divided into three groups depending on neonatal weight. In the group of 200 patients, 60 (30%) delivered LGA and 9 (4.5%) SGA newborns.

Fetal growth trajectories show different patterns among fetuses with growth abnormalities in women with type 1 diabetes. The moment, when fetal growth curves diverge, seems to take place in the second trimester, just after the 23rd week of gestation.

It suggests that fetal growth abnormalities in type 1 diabetes may have its roots much earlier than expected. In the first trimester, there were differences in LDL-cholesterol, total cholesterol, triglyceride levels and in insulin requirements between AGA, SGA and LGA subgroups.