Department of Obstetrics, Perinatology and Neonatology, Centre of Postgraduate Medical Education, Warsaw, Poland.
Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Warsaw, Poland.
Front Endocrinol (Lausanne). 2023 Jan 17;13:1044655. doi: 10.3389/fendo.2022.1044655. eCollection 2022.
The function of the thyroid gland during pregnancy undergoes physiological changes to ensure the proper amount of thyroid hormones for both the pregnant woman and the fetus. Multiple pregnancies (MP) are characterized by specific differences compared to single pregnancies, e.g., higher concentrations of human chorionic gonadotropin, which also affect thyroid function. The aim was to collect available knowledge on maternal thyroid function in MP.
We have systematically searched three databases: the PubMed/MEDLINE, Scopus and the Cochrane Library. The last search was run on the 4th of August 2022. We included full-text original observational and experimental studies written in English. Case reports, editorials, letters, conference abstracts, reviews and meta-analyses were excluded. No time criterion was established. Studies were considered eligible if at least one maternal thyroid function test was performed and reported. Studies on MP with a co-existing mole were excluded. The risk of bias was assessed with the use of the AXIS tool. The qualitative synthesis of evidence was applied.
The search strategy resulted in the identification of 821 manuscripts. After removing duplicates, we screened the titles and abstracts of 552 articles, out of which 57 were selected for full-text analysis. Finally, 12 articles were included in the review. They were conducted in 6 different countries and published between the years 1997 and 2022. The number of examined women with MP ranged from 9 to 1 626.
Thyroid function differs between women with MP and SP. Scarce data are available on the topic, but MPs are most likely characterized by higher HCG levels, which influences thyroid-stimulating hormone and free thyroid hormone levels. These differences are mainly expressed in the 1st trimester of pregnancy. Separate population-based reference ranges are needed to correctly diagnose thyroid diseases in MP and to avoid unnecessary treatment. Further research is needed to fill the knowledge gaps.
怀孕期间甲状腺的功能会发生生理变化，以确保孕妇和胎儿获得适量的甲状腺激素。多胎妊娠（MP）与单胎妊娠有明显的不同，例如人绒毛膜促性腺激素（hCG）浓度更高，这也会影响甲状腺功能。本研究旨在收集多胎妊娠中母体甲状腺功能的相关知识。
我们系统地检索了三个数据库：PubMed/MEDLINE、Scopus 和 Cochrane Library。最后一次检索是在 2022 年 8 月 4 日进行的。我们纳入了以英文撰写的完整的观察性和实验性研究。排除了病例报告、社论、信件、会议摘要、综述和荟萃分析。没有设定时间标准。如果至少进行了一次母体甲状腺功能检测并报告了结果，则认为研究符合条件。排除了多胎妊娠中存在绒毛膜瘤的研究。使用 AXIS 工具评估偏倚风险，并进行证据的定性综合。
检索策略共确定了 821 篇手稿。去除重复项后，我们筛选了 552 篇文章的标题和摘要，其中 57 篇被选入全文分析。最终，有 12 篇文章被纳入综述。这些研究分别在 6 个不同的国家进行，发表时间在 1997 年至 2022 年之间。接受检查的多胎妊娠妇女人数从 9 到 1626 不等。
多胎妊娠妇女的甲状腺功能与单胎妊娠妇女不同。关于这个主题的可用数据很少，但多胎妊娠妇女的 hCG 水平可能更高，这会影响促甲状腺激素和游离甲状腺激素水平。这些差异主要在妊娠早期表现出来。需要建立单独的基于人群的参考范围，以正确诊断多胎妊娠中的甲状腺疾病，并避免不必要的治疗。需要进一步研究来填补知识空白。
