Women with hypothyroxinemia had higher BMI, glucose and triglyceride levels than women with normal thyroid function. There was no difference in these parameters between women with mild hypothyroidism and those with normal thyroid function.
In the entire group of pregnant women, the lower the free T4 levels, the higher the BMI, glucose and triglyceride levels. TSH levels in the mother did not correlate with any metabolic parameter.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study demonstrates that hypothyroxinemia in the mother is associated with worse metabolic abnormalities, including increased obesity and higher glucose and triglyceride levels as compared to pregnant women with normal thyroid function, similar to findings of a prior smaller study. Surprisingly, this study showed no difference in metabolic abnormalities between pregnant women with subclinical hypothyroidism and those with normal thyroid function. It is not known whether obesity in the mother results in the thyroid abnormalities and metabolic changes or whether the thyroid abnormalities causes obesity and the metabolic changes in pregnancy. Further studies are needed to find the free T4 threshold to diagnose maternal hypothyroxinemia and whether thyroid hormone treatment for this condition has benefits for either the mother or the baby.
— Alina Gavrila, MD, MMSC
ATA THYROID BROCHURE LINKS
Thyroid Disease and Pregnancy: http://www.thyroid.org/thyroid-disease-pregnancy/
Thyroid Function Tests: http://www.thyroid.org/thyroid-function-tests/