Risk Assessment of Diabetes Mellitus During and After Pregnancy in Women With Prolactinomas.

Context: Prolactin (PRL) is a crucial mediator of glucoinsulinemic metabolism.

Objective: This work aims to dissect glucose metabolism during and after pregnancy in patients with prolactinomas.

Methods: A total of 52 patients treated with cabergoline (CAB) were evaluated before conception, during pregnancy, and up to 10 years after delivery. During pregnancy, CAB was discontinued, while it was restarted in 57.7% of patients after delivery, due to recurrent hyperprolactinemia (RH). Hormonal (serum PRL) and metabolic (glycated hemoglobin A1c [HbA1c], fasting glucose [FG], glucose tolerance) parameters were assessed.

Results: During pregnancy, PRL gradually increased, while FG remained stable. An inverse correlation between PRL and FG was found in the first (P = .032) and third (P = .048) trimester. PRL percentage increase across pregnancy was inversely correlated with third-trimester FG. Serum PRL before conception emerged as a predictive biomarker of third-trimester FG (t = 2.603; P = .048). Older patients with lower HbA1c in the first trimester and lower FG at 3 years post partum delivered infants with reduced birth weight. Breastfeeding up to 6 months correlated with lower FG at 4 and 10 years post partum. A positive correlation between BMI and FG at 10 years after delivery (P = .03) was observed, particularly in overweight/obese patients requiring higher CAB doses. Patients with RH who had to restart CAB showed shorter breastfeeding duration and higher FG at 2 years post partum.

Conclusion: Low PRL levels before pregnancy may be detrimental to FG during pregnancy. CAB duration and dose may influence long-term glucose tolerance, besides family history and BMI. Preconception metabolic management should be recommended to reduce the risk of gestational and type 2 diabetes mellitus.