Metformin is a medication commonly used to manage blood sugar levels in people with type 2 diabetes and is also prescribed during pregnancy, particularly for women with gestational diabetes or polycystic ovary syndrome (PCOS). The question of whether metformin use during pregnancy could potentially affect child development is complex and involves multiple factors including the drug’s effects on fetal growth, neurodevelopment, and long-term health outcomes.
During pregnancy, gestational diabetes mellitus (GDM) is a condition where a woman without previously diagnosed diabetes develops high blood sugar levels. GDM itself poses risks to both mother and child, including increased chances of developmental delays and neurodevelopmental disorders such as autism spectrum disorder and ADHD in children. These risks highlight the importance of managing blood sugar effectively during pregnancy to reduce harm to the developing fetus.
Metformin crosses the placenta, meaning it can reach the fetus. However, it is not considered teratogenic, which means it does not cause birth defects. Studies have shown that babies born to mothers treated with metformin tend to have lower birth weights and less visceral fat, which might reduce their risk of insulin resistance later in life. On the other hand, metformin use has been linked to an increased risk of babies being small for gestational age, which means they are smaller than the typical size for their gestational age. This smaller size at birth can sometimes be associated with other health concerns, although the full implications are still being studied.
One notable finding is that children exposed to metformin in utero have shown higher rates of allergies and eczema compared to those not exposed. This suggests that while metformin may reduce some risks, such as maternal infections during pregnancy, it might also influence the child’s immune system development in ways that increase susceptibility to allergic conditions. The exact mechanisms behind this are not fully understood, and more research is needed to clarify these effects.
Regarding neurodevelopment, the evidence is still emerging. Gestational diabetes itself is linked to cognitive dysfunction risks in offspring, but whether metformin modifies these risks positively or negatively is less clear. Some studies suggest that managing gestational diabetes effectively with metformin could reduce the severity of neurodevelopmental problems by controlling maternal blood sugar levels, but direct effects of metformin on brain development have not been definitively established.
Long-term follow-up studies of children exposed to metformin during pregnancy have observed differences in growth patterns, such as increased body mass index (BMI
