Levothyroxine therapy decreases low birth weight in subclinical hypothyroidism
Fewer babies with low birth weight and low Apgar score were born to pregnant women with subclinical hypothyroidism who started levothyroxine therapy, according to recent study findings presented at the 15th International Thyroid Congress and 85th Annual Meeting of the American Thyroid Association.
“Subclinical hypothyroidism has been associated with an increased risk of adverse pregnancy outcomes in some, but not all, studies,” the researchers wrote. “Uncertainty remains regarding the impact of levothyroxine therapy on improving health outcomes in pregnant women with [subclinical hypothyroidism].”
N. Singh Ospina , MD, of the Mayo Clinic, and colleagues evaluated medical records of women meeting the criteria for subclinical hypothyroidism during pregnancy between January 2011 and December 2013 to determine the effect of levothyroxine therapy among them. Participants were divided into two groups, those assigned levothyroxine therapy (n = 79) and those not on levothyroxine therapy (controls; n = 285). Follow-up was conducted until loss of pregnancy or postpartum visit.
Compared with controls, the levothyroxine group had higher BMI (P = .02) and thyroid-stimulating hormone levels (P < .0001).
A significant decrease in pregnancy loss was found among the levothyroxine group (5.1%) compared with controls (8.8%); however, this was not statistically significant.
Significant decreases for low birth weight (P = .02) and Apgar score of seven or less at 5 minutes (P = .02) was found among the levothyroxine group compared with controls.
“Our study found an association of [levothyroxine] therapy with decreases in low birth weight and low Apgar score, however, no difference in pregnancy loss and other maternal and neonatal outcomes,” the researchers wrote. “This association awaits confirmation in randomized trials before the widespread use of [levothyroxine] therapy in pregnant women with [subclinical hypothyroidism].” – by Amber Cox
Maraka S, et al. Oral 70. Presented at: 15th International Thyroid Congress and 85th Annual Meeting of the American Thyroid Association (ITC/ATA); Oct. 18-23, 2015; Lake Buena Vista, Fla.
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