Polycystic ovary syndrome (PCOS) is a common hormonal disorder affecting women of reproductive age. It is characterized by multiple small cysts in the ovaries, irregular menstrual periods, and high levels of male hormones. Women with PCOS are at higher risk of developing hypothyroidism, a condition in which the thyroid gland doesn't produce enough hormones. Both PCOS and hypothyroidism are associated with adverse pregnancy outcomes, but the interaction between these conditions during pregnancy is not well understood.
A recent clinical trial investigated the thyroid status and its association with pregnancy complications in women with PCOS, and in relation to metformin treatment. Metformin is a drug commonly used to treat PCOS, as it can improve insulin resistance and lower blood sugar levels.
The study involved 288 pregnant women with PCOS who were randomized to treatment with metformin or a placebo from the first trimester to delivery. The researchers measured serum levels of thyroid stimulating hormone (TSH) and free thyroxine (fT4) at several points during pregnancy and related them to metformin treatment and pregnancy complications. They also analyzed thyroid peroxidase antibodies (TPO-ab) at inclusion and at gestational week 36.
The results showed that the overall prevalence of subclinical and overt hypothyroidism was low, with 1.5% and 0% of the participants affected, respectively. The TSH level was not affected by metformin, but fT4 was significantly higher in the metformin group, with less decrease throughout pregnancy compared to the placebo group. This suggests that metformin treatment during pregnancy was associated with less decrease in fT4 compared to placebo, while it did not affect TSH.