Thyroid function after assisted reproductive technology in women free of thyroid disease

Objective: To evaluate thyroid function in women undergoing a first assisted reproductive technology (ART) procedure and to compare women with ongoing pregnancy or miscarriage. Design: Prospective cohort study. Setting: Tertiary referral center. Patient(s): Seventy-seven women free of thyroid disease. Intervention(s): Serum TSH and FT4 were determined before and 2, 4, and 6 weeks after ET. All women received the same ART protocol. Main Outcome Measure(s): Thyroid function. Result(s): Forty-five women had ongoing pregnancies, and 32 suffered a miscarriage after 6.7 weeks (range 5-11). Mean age and number of ET were similar in both groups. Compared with baseline values, TSH and FT4 increased significantly 2 weeks after ET (ongoing pregnancies group: TSH 15 +/- 1.3 vs. 1.6 +/- 0.8 mU/L and FT4 13.8 +/- 1.4 vs. 12.4 +/- 1.8 ng/L; miscarriage group: TSH 2.1 +/- 1.0 vs. 1.5 +/- 0.7 mU/L and FT4 14.2 +/- 2.0 vs. 12.4 +/- 1.9 ng/L). Pregnancy outcome did not affect thyroid function and its evolution over time. Conclusion(s): In women free of thyroid diseases, thyroid function changed significantly after ART, but these changes were not different between women with ongoing pregnancy and miscarriage. (c) 2005 by American Society for Reproductive Medicine.