An underperforming thyroid gland can lead to pregnancy complications, a review of thousands of medical records suggests.
The thyroid produces a hormone that regulates how the body uses energy. Underachieving thyroids in pregnancy have been linked to preterm birth, but the full array of risk is unknown.
Pauline Mendola and colleagues at the National Institute of Child Health and Human Development in Rockville, Md., analyzed records of more than 220,000 pregnancies from 2002 to 2008. Among them were more than 3,000 from women with low thyroid hormone, or hypothyroidism.
The researchers had no information on how the condition was treated, but clear differences emerged between the pregnancies of women with and without hypothyroidism. The women with the condition were more likely to have gestational diabetes, a cesarean section delivery, a preterm birth, admission to the intensive care unit or a complication called preeclampsia. The new findings appear May 29 in the Journal of Clinical Endocrinology & Metabolism.