Takeaway
- Treatment of subclinical and borderline hypothyroidism does not improve pregnancy continuation rates in women with a history of repetitive miscarriage.
Why this matters
- Recurrent pregnancy loss is defined as 2 or more spontaneous abortions and has been associated with thyroid disease.
- Treatment should be initiated with serum thyroid-stimulating hormone (TSH) >4 mIU/L.
Key results
- 1.8% of cohort were hyperthyroid, 72% were euthyroid, 19.4% were borderline, 5.4% were subclinical, and 0.7% had overt hypothyroidism.
- Of the 58.7% participants who had a thyroid peroxidase antibody test, 9.25% were positive in euthyroid, 16.5% positive in borderline, and 35.3% positive in subclinical hypothyroid.
- Pregnancy continuation rates did not differ between participants who were euthyroid vs borderline (with and without treatment).
- Thyroid autoimmunity treatment did not improve pregnancy in subclinical hypothyroid cases.
Study design
- Retrospective cohort study.
- Participants who attended a recurrent pregnancy loss clinic and had a TSH level measured between 2011 and 2016 were identified (n=992).
- Participants were offered preconception levothyroxine if TSH level was >2.5 mIU/L.
- Outcome measure was continued pregnancy beyond 10 weeks.
- Funding: Department of Obstetrics and Gynaecology, University of British Columbia.
Limitations
- Treatment guidelines may have changed over the course of the study.
References
References