Do elevated TSH levels predict early pregnancy loss in ART patients?

Introduction: The upper limit of normal TSH has been revised from 5 mIU/L to 2.5 mIU/L. We sought to evaluate IVF patients and the association between abnormal TSH and early pregnancy loss.

Methods: A retrospective study of patients who had TSH levels measured within the 2 weeks prior to their fresh autologous IVF cycles (2002-2014). Cohorts were stratified by oocyte age (<35, [35-38), [38-41), [41-43) and ≥43 years), and TSH level [(0-0.5], (0.5-2.5], (2.5-5], and (5-23) mIU/L]. Patients were followed until pregnancy loss or delivery. Model was assessed by chi-square of ANOVA with significance at p < 0.05.

Results: TSH was abnormally elevated (>5 mIU/L), mildly elevated ((2.5-5] mIU/L) or suppressed (≤0.5 mIU/L) in 46, 317 and 65 of the 1201 total cycles, respectively. Treatment resulted in 630 pregnancies, 524 clinical pregnancies and 409 deliveries. Pregnancy loss rates were increased in patients ≥38 yo (p < 0.001) but not [35-38) yo (p = 0.40) compared with those <35 yo. Early pregnancy loss rate was not associated with TSH level (p > 0.30) compared with euthyroid patients after adjusting for oocyte age.

Conclusion: Early pregnancy loss rate in IVF patients appears to have no relation to recent TSH levels.