Impact of subclinical hypothyroidism in women with recurrent early pregnancy loss

The high prevalence of subclinical hypothyroidism among women with recurrent early pregnancy loss did not appear to impact the live-birth rates in this population.


Lia A. Bernardi, M.D., Ronald N. Cohen, M.D., Mary D. Stephenson, M.D., M.Sc.

Volume 100, Issue 5, Pages 1326-1331.e1, November 2013



To assess the impact of subclinical hypothyroidism (SCH) in women with recurrent early pregnancy loss (REPL).


Observational cohort study.


REPL program in an academic medical center.


286 women with a history of ≥2 pregnancy losses <10 weeks. Intervention(s):

From 2004–2007, no treatment for women with SCH (thyroid-stimulating hormone [TSH] >2.5 mIU/L with a normal free thyroxine or free thyroxine index); from 2008 onward, levothyroxine treatment prepregnancy to maintain TSH ≤2.5 mIU/L.

Main Outcome Measure(s):

Live-birth rate (LBR).


The prevalence of SCH was 55 (19%) of 286 in this REPL cohort. The cumulative LBR was 27 (69%) of 39 for women with SCH versus 104 (74%) of 141 for euthyroid women. The per-pregnancy LBR was 34 (49%) of 69 for SCH versus 129 (58%) of 221 for euthyroid women. When the LBR was compared between treated and untreated SCH, the cumulative LBR was 17 (71%) of 24 versus 10 (67%) of 15, respectively. The per-pregnancy LBR for SCH treated versus untreated women was 22 (48%) of 46 versus 12 (52%) of 23, respectively.


Although there was a high prevalence of SCH in the REPL cohort, there was no statistically significant difference in the subsequent live-birth rate when comparing women with SCH and euthyroid women, or treated and untreated SCH.

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