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

Abstract

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 2.5 +/- 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.