Shanghai Key Laboratory of Maternal Fetal Medicine, Department of Women's and Children's Health Care, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, China.
Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Front Endocrinol (Lausanne). 2024 Aug 16;15:1431621. doi: 10.3389/fendo.2024.1431621. eCollection 2024.
Thyroid function during pregnancy fluctuates with gestational weeks, seasons and other factors. However, it is currently unknown whether there is a fetal sex-specific thyroid function in pregnant women. The purpose of this study was to investigate the fetal sex differences of maternal thyroid-stimulating hormone (TSH) and free thyroxine (FT4) in pregnant women.
This single-center retrospective real-world study was performed by reviewing the medical records of pregnant women who received regular antenatal health care and delivered liveborn infants in Shanghai First Maternity and Infant Hospital (Pudong branch), from Aug. 18, 2013 to Jul. 18, 2020. Quantile regression was used to evaluate the relationship between various variables and TSH and FT4 concentrations. The quantile regression also evaluated the sex impact of different gestational weeks on the median of TSH and FT4.
A total of 69,243 pregnant women with a mean age of 30.36 years were included. 36197 (52.28%) deliveries were boys. In the three different trimesters, the median levels (interquartile range) of TSH were 1.18 (0.66, 1.82) mIU/L and 1.39 (0.85, 2.05) mIU/L, 1.70 (1.19, 2.40) mIU/L; and the median levels (interquartile range) of FT4 were 16.63 (15.16, 18.31) pmol/L, 14.09 (12.30, 16.20) pmol/L and 13.40 (11.52, 14.71) pmol/L, respectively. The maternal TSH upper limit of reference ranges was decreased more in mothers with female fetuses during gestational weeks 7 to 12, while their FT4 upper limit of the reference ranges was increased more than those with male fetuses. After model adjustment, the median TSH level was 0.11 mIU/L lower ( <0.001), and FT4 level was 0.14 pmol/L higher ( <0.001) for mothers with female fetuses than those with male fetuses during gestational weeks 9 to 12.
We identified sexual dimorphism in maternal thyroid function parameters, especially during 9-12 weeks of pregnancy. Based on previous research, we speculated that it may be related to the higher HCG levels of mothers who were pregnant with girls during this period. However, longitudinal studies are needed to determine if fetal sex differences impact the maternal thyroid function across pregnancy.
孕妇的甲状腺功能随妊娠周数、季节和其他因素而波动。然而，目前尚不清楚孕妇的甲状腺功能是否存在胎儿性别特异性。本研究旨在探讨孕妇的母体促甲状腺激素（TSH）和游离甲状腺素（FT4）的胎儿性别差异。
这是一项单中心回顾性真实世界研究，通过回顾 2013 年 8 月 18 日至 2020 年 7 月 18 日在上海第一妇婴保健院（浦东分院）接受常规产前保健并分娩活产儿的孕妇的病历进行。使用分位数回归评估各种变量与 TSH 和 FT4 浓度之间的关系。分位数回归还评估了不同妊娠周数对 TSH 和 FT4 中位数的性别影响。
共纳入 69243 名平均年龄为 30.36 岁的孕妇，其中 36197 名（52.28%）分娩的是男孩。在三个不同的孕期中，TSH 的中位数（四分位距）分别为 1.18（0.66，1.82）mIU/L 和 1.39（0.85，2.05）mIU/L，1.70（1.19，2.40）mIU/L；FT4 的中位数（四分位距）分别为 16.63（15.16，18.31）pmol/L、14.09（12.30，16.20）pmol/L 和 13.40（11.52，14.71）pmol/L。孕 7-12 周时，母体 TSH 参考范围上限在女性胎儿母亲中降低更多，而 FT4 参考范围上限在女性胎儿母亲中升高更多。调整模型后，孕 9-12 周时，母体 TSH 水平中位数低 0.11mIU/L（<0.001），FT4 水平高 0.14pmol/L（<0.001）。
我们发现母体甲状腺功能参数存在性别二态性，尤其是在妊娠 9-12 周期间。基于之前的研究，我们推测这可能与在此期间怀有女孩的母亲的 HCG 水平较高有关。然而，需要进行纵向研究来确定胎儿性别差异是否会影响整个妊娠期间的母体甲状腺功能。
