Metformin use during pregnancy showed no long-term adverse effects on children or mothers for at least 11 years after childbirth, according to research presented at ENDO 2024, the Endocrine Society's annual meeting in Boston, Mass.

The study, led by Deep Dutta, M.D., aimed to assess the long-term outcomes of metformin use during pregnancy compared to insulin. This systematic review and meta-analysis included data from 10,117 child-mother pairs from seven different study cohorts.

"Our study provides reassuring data on the long-term safety of metformin use during pregnancy for children and their mothers," Dutta said. "Metformin has been extensively used for managing raised blood glucose values in pregnancy for many decades. It is the only blood glucose-lowering oral medication approved for use in pregnancy."

The researchers analyzed data from studies that evaluated children at ages 5-11 years and their mothers. They compared various health metrics, including BMI, waist circumference, dual-energy X-ray absorptiometry (DXA) total body fat, DXA total body fat percentage, DXA total body fat-free mass, MRI visceral adipose tissue, and magnetic-resonance spectroscopy liver fat percentage.

The results showed no significant differences between children born to mothers who took metformin and those who used insulin during pregnancy. Children at 9 years of age born to mothers who used metformin during pregnancy had similar BMI, waist circumference, DXA total body fat, and other health measures compared to those born to mothers who used insulin.

Additionally, the rates of obesity, diabetes, and motor development issues in children up to 11 years after childbirth were similar between the two groups. Maternal outcomes at the 9-year follow-up were also comparable. Maternal age, BMI, and risks of developing diabetes showed no significant differences between pregnancies exposed to metformin and those exposed to insulin.

"This study offers critical insights that could impact the management of raised blood glucose values during pregnancy, potentially improving outcomes for both mothers and their children," Dutta said.

No conflicts of interest were disclosed.