The Dynamic Changes in Maternal Thyroid Parameters Across the Three Trimesters and Their Differential Effects on the Occurrence of Adverse Obstetric Outcomes

Zheng Yang; Jingli Sun; Jinguang Wang; Xiaohui Jin; Yiyang Gao; Zhenyu Lin; Chenling Fan; Dongdong Luo; Deping Wang; Weiping Teng; Zhongyan Shan; Jing Li

doi:10.2174/0118715303351648250120113846

The Dynamic Changes in Maternal Thyroid Parameters Across the Three Trimesters and Their Differential Effects on the Occurrence of Adverse Obstetric Outcomes

Endocr Metab Immune Disord Drug Targets. 2025 Mar 4. doi: 10.2174/0118715303351648250120113846. Online ahead of print.

Authors

Zheng Yang^{1

2}, Jingli Sun³, Jinguang Wang³, Xiaohui Jin¹, Yiyang Gao¹, Zhenyu Lin¹, Chenling Fan¹, Dongdong Luo¹, Deping Wang¹, Weiping Teng¹, Zhongyan Shan¹, Jing Li¹

Affiliations

¹ Department of Endocrinology and Metabolism, Institute of Endocrinology, Liaoning Provincial Key Laboratory of Endocrine Diseases, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Hospital of China Medical University, Shenyang, 110001, P. R. China.
² Department of Endocrinology, Nanyang Central Hospital, Henan 473000, P. R. China.
³ Department of Obstetrics and Gynecology, General Hospital of Northern Theater Command (Heping Campus), Shenyang, 110001, P. R. China.

PMID: 40045850
DOI: 10.2174/0118715303351648250120113846

Abstract

Objective: Thyroid parameters undergo significant dynamic changes during pregnancy. This study aimed to comprehensively analyze the impact of abnormal thyroid parameters in each trimester on the incidence of common adverse obstetric outcomes.

Methods: Blood samples drawn for thyroid parameters in each trimester during the antenatal period were determined after the participants gave birth. Serum thyrotropin, free thyroxine, free triiodothyronine, anti-thyroid peroxidase antibody (TPOAb), and anti-thyroglobulin antibody (TgAb) levels were tested using electrochemiluminescence immunoassays.

Results: Among all the participants, TAI and hypothyroxinemia in the first trimester (T1) were significantly related to an increased risk of gestational hypertension [OR=5.136, 95% CI 1.537-17.158 and OR=7.683, 95% CI: 1.890-31.229, respectively]. Additionally, subclinical hypothyroidism in T1 was independently associated with a higher risk of postpartum hemorrhage [OR = 38.063, 95% CI 2.091-692.834].Besides, subclinical thyrotoxicosis in T1 showed a significant correlation with a raised risk of small for gestational age [OR=14.650, 95% CI 1.221-175.760]. Among euthyroid women during the whole pregnancy, either TPOAb+ or TgAb+ in the third trimester was an independent risk factor of premature birth [OR=5.092, 95% CI 1.059-24.481] and low birth weight [OR=8.165, 95% CI 1.717-38.824], respectively.

Conclusion: Our findings indicate the importance of screening thyroid parameters in early pregnancy and the need to dynamically monitor these parameters throughout the entire pregnancy.

Keywords: Anti-thyroid peroxidase antibody; anti-thyroglobulin antibody; obstetric outcomes; pregnancy; thyroid dysfunction; trimester..