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

Abstract

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.

Chinese abstract

引言: 正常TSH上限已经从5 mIU/L修订为2.5 mIU/L。我们试图评价IVF患者TSH水平异常和早期妊娠丢失的关系。

方法: 采用回顾性研究, 对2002-2014年间新鲜周期自体移植前2周内接受了TSH水平检测的IVF患者进行分析, 研究对象按卵母细胞的卵龄(＜35, [35–38), [38–41), [41–43) 和 ≥43年)和TSH [(0–0.5], (0.5–2.5], (2.5–5], and (5–23) mIU/L]水平分层。随访患者直至妊娠丢失或分娩。采用方差分析、卡方检验分析数据, 以P＜0.05为差异有统计学意义。

结果: 在1201个周期中, TSH异常升高(>5 mIU/L)、轻度升高((2.5–5] mIU/L)和 TSH降低(≤0.5 mIU/L)分别为46、317和65个周期。治疗结果630例生化妊娠, 524例临床妊娠, 409例分娩。与卵龄＜35年的患者相比, 卵龄>38年的患者妊娠丢失率增高(p＜0.001), 而卵龄在[35-38)年之间的患者妊娠丢失率没有差异(p＝0.40)。调整卵龄后, 和甲状腺功能正常的患者相比, 早期妊娠丢失率不随TSH水平变化 (p > 0.30) 无关。

结论: IVF患者的早期妊娠丢失率和近期TSH水平没有相关性。

Keywords:

• Early pregnancy loss
• euthyroid
• in vitro fertilization
• subclinical hypothyroidism
• thyroid stimulating hormone

Declaration of interest

The authors report no declarations of interest.

JAG was supported by the NIH MSTP grant GM007280 to the Medical Scientist Training Program.