Subclinical hypothyroidism in women’s health: from pre- to post-menopause

Abstract

Objective

Subclinical hypothyroidism (SCH) is a quite frequent condition among women, affecting 3–12% of the general population. Its consequences on women’s health in reproductive age, pregnancy and menopause have been extensively investigated but data about the effective impact of treatment with levothyroxine (LT4) remain conflicting.

Methods

This is a narrative review and analysis of the most relevant data until June 2021.

Results

SCH may affect reproduction. Evidence suggests that women with SCH undergoing assisted reproductive technique (ART) may benefit from LT4 therapy whereas there are no conclusive data regarding women attempting natural conception. SCH may be associated with several negative pregnancy outcomes, that is to say recurrent pregnancy loss (RPL), preterm delivery, preeclampsia and neurocognitive disturbances of offspring. However, the protective role of LT4 treatment has been established in selected cases, for instance in thyroid peroxidase antibody (TPOAb) -positive women with TSH greater than the pregnancy specific reference range and/or in TPOAb-negative women with TSH >10.0 mIU/L. In menopause, SCH can worsen the negative cardio-metabolic effects of hormonal loss and/or aging, by exacerbating dyslipidaemia and hypertension. Nevertheless, robust data about the benefits of LT4 therapy are still lacking and treatment should be encouraged with caution.

Conclusions

SCH represents a challenging condition during pre- and post- menopause. An aware knowledge of its possible principal consequences could help all clinicians who are involved in women’s health to manage more properly it, preventing its sequelae.

摘要

目的:亚临床甲状腺功能减退症(SCH)在女性中相当常见, 影响3-12%的总人口。它对育龄期、妊娠期和绝经期女性健康的影响已被广泛研究, 但关于左旋甲状腺素(LT4)治疗的有效性的相关数据存在矛盾。

方法:这是对截止至2021年6月最新相关数据的叙述性回顾和分析。

结果:SCH可能影响女性生殖功能。有证据表明, 接受辅助生殖技术(ART)的患有SCH的妇女可能受益于LT4治疗, 然而没有关于尝试自然受孕的妇女的结论性数据。SCH可能与几种负面妊娠结果相关, 即复发性流产(RPL)、早产、先兆子痫和后代的神经认知障碍。然而, LT4治疗的保护作用已在选定的病例中得到证实, 例如在TSH高于妊娠特异性参考范围且甲状腺过氧化物酶抗体(TPOAb)阳性女性和/或TSH >10.0 mIU/L的TPOAb阴性妇女中。在绝经期, SCH可通过加剧血脂异常和高血压而加重激素丢失和/或衰老的并且对心脏代谢产生负面效应。然而, 仍然缺乏关于LT4治疗益处的可靠数据, 应该谨慎鼓励治疗。

结论:在绝经前后, SCH是一种具有挑战性的疾病。了解其可能的主要后果可以帮助所有临床医生更好地管理患者的疾病, 防止其后遗症。

Keywords:

• Subclinical hypothyroidism
• levothyroxine
• pregnancy
• menopause
• reproduction
• thyroid autoimmunity
• dyslipidaemia
• recurrent pregnancy loss

Author contributions

The authors contributed equally to this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).