Skeletal malformations and growth disturbances in fetuses of mild diabetic rats

Introduction: Currently, diabetes mellitus represents one of the medical conditions that more frequently complicates pregnancy affecting the fetus’s growth and development. Objective: To determine the skeletal malformations and growth alterations in fetuses of diabetic Wistar rats. Materials and methods: We used a neonatally streptozotocin-induced mild diabetes model (STZ 100 mg/kg body weight - subcutaneously) in Wistar rats. In adulthood, healthy and diabetic rats were mated with healthy males of the same age and strain. On day 20 of gestation, a cesarean was performed under anesthesia. Fetuses were removed, weighed, and classified as small (SPA), adequate (APA), and large (LPA) for the gestational age. Selected fetuses were processed for skeletal anomaly and ossification sites analysis. Results: In the offspring of diabetic rats, there was a higher percentage of fetuses classified as small or large and a lower percentage of fetuses with adequate weight; the fetal weight mean was lower and there were fewer sites of ossification. Alterations were observed in the ossification of the skull, sternum, spine, ribs and fore and hind limbs; and also, there was a direct correlation between fetal weight and ossification degree. There were congenital malformations associated with fusion and bifurcation of the ribs, as well as changes indicative of hydrocephaly, such as the dome shape of the skull, a wide distance between parietals, and the width of the anterior and posterior fontanels. Conclusion: Moderate diabetes during pregnancy alters fetal growth and development with macrosomia and intrauterine growth restriction, as well as skeletal malformations.