Issue: February 2018
December 12, 2017
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Levothyroxine treatment does not alter pregnancy outcomes

Issue: February 2018
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Jie Qiao
Jie Qiao
TIanpei Hong
Tianpei Hong

Miscarriage, intrauterine pregnancy and live-birth rates were not affected with levothyroxine treatment in women who were antithyroperoxidase-antibody positive and undergoing in vitro fertilization and embryo transfer, according to findings published in JAMA.

Jie Qiao, MD, PhD, of the Center of Reproductive Medicine, and Tianpei Hong, MD, PhD, of the department of endocrinology and metabolism, both at Peking University Third Hospital in Beijing, and colleagues evaluated 600 women (mean age, 31.6 years) who were antithyroperoxidase-antibody positive undergoing IVF and embryo transfer at Peking University Third Hospital. Participants were enrolled in the study between Sept. 6, 2012, and June 15, 2016, and follow-up was conducted until March 20, 2017.

“It is worth noting that in our trial, women with known comorbidities related to miscarriage, including recurrent miscarriage, known history of autoimmune diseases or presence of their markers (such as antinuclear antibody, anticardiolipin antibody and lupus anticoagulants), were excluded from this trial,” Qiao and Hong told Endocrine Today. “Therefore, our findings might not be applicable to women at increased risk for miscarriage.”

Participants were randomly assigned to levothyroxine treatment (n = 300; intervention group) or no levothyroxine treatment (n = 300; control group) to assess the effect of treatment on miscarriage (pregnancy loss before 28 weeks of gestation), intrauterine pregnancy rate (fetal cardiac activity seen at sonography observation on the 30th day after embryo transfer) and live-birth rate (at least one live birth after 28 weeks of gestation).

No significant differences were observed between the intervention and control groups for miscarriage rate (intervention, 10.3% vs. control, 10.6%), clinical intrauterine pregnancy rate (35.7% vs. 37.7%) or live-birth rate (31.7% vs. 32.3%).

Participants in the intervention group were more likely to have a twin pregnancy compared with the control group (36.4% vs. 28.3%). Preterm delivery rates among participants who had a live birth were 22.1% for the intervention group and 19.6% for the control group.

“We recommend against levothyroxine treatment for euthyroid women undergoing IVF and embryo transfer who test positive for thyroid autoantibodies,” Qiao and Hong said. “Levothyroxine treatment should be started after pregnancy when thyroid-stimulating hormone level exceeds the upper limit of the local normal range of pregnancy. Many infertile women with positive thyroid autoantibodies who are scheduled for IVF and embryo transfer receive levothyroxine treatment. Our findings suggest that preventive levothyroxine treatment is not necessary in this population before a pregnancy is confirmed.”by Amber Cox

For more information:

Jie Qiao, MD, PhD, can be reached at jie.qiao@263.net and Tianpei Hong, MD, PhD, can be reached at tpho66@bjmu.edu.cn.

Disclosures: Qiao and Hong report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.