Feng Xinyuan, Sun Huijie, Liu Tianci, Li Liang
Department of Ultrasound, The First Affiliated Hospital of Anhui Medical University, No.218 Jixi Road, Shushan District, Hefei, 230022, China.
BMC Pregnancy Childbirth. 2025 May 20;25(1):594. doi: 10.1186/s12884-025-07714-w.
Maternal hypothyroidism has been associated with impaired offspring neurodevelopment but the underlying mechanisms are unclear now. We hypothesize that maternal hypothyroidism influences the development of fetal hypothalamic-pituitary-thyroid (HPT) axis, and thereby indirectly affects postnatal cognitive development.
This prospective observational study included singleton pregnancies with hypothyroidism before 14 weeks of gestation. Ultrasound measurements of fetal thyroid size were performed at 20-24 and 28-32 weeks. The primary outcome was fetal thyroid volumes at two time points; and the secondary outcomes were pregnancy and neonatal outcomes, including birthweight, delivery weeks, preterm birth, stillbirth or miscarriage, and neonatal thyroid functions on the third postnatal day.
A total of 136 women participated in this study, comprising 68 with hypothyroidism and 68 with uncomplicated pregnancies. There was no significant difference between the hypothyroidism and control group of fetal thyroid volumes measured at gestation of 20-24 weeks (230.58 ± 63.75mm3 vs. 230.15 ± 75.69mm3, P = 0.98) and 28-32 weeks (491.55 ± 154.88mm3 vs. 450.16 ± 136.13mm3, P = 0.059). Additionally, the incidence of adverse events was also similar between groups. These findings remained unchanged after adjusting for confounding factors.
The results of this study suggest that maternal hypothyroidism may not significantly influence the fetal HPT axis. However, it is important to emphasize that this conclusion is based solely on data from mothers with well-controlled hypothyroidism. Moreover, the small prevalence of overt clinical hypothyroidism should be considered when interpreting this finding.
母亲甲状腺功能减退与后代神经发育受损有关，但目前其潜在机制尚不清楚。我们假设母亲甲状腺功能减退会影响胎儿下丘脑 - 垂体 - 甲状腺（HPT）轴的发育，从而间接影响出生后的认知发育。
这项前瞻性观察性研究纳入了妊娠14周前患有甲状腺功能减退的单胎妊娠。在孕20 - 24周和28 - 32周进行胎儿甲状腺大小的超声测量。主要结局是两个时间点的胎儿甲状腺体积；次要结局是妊娠和新生儿结局，包括出生体重、分娩孕周、早产、死产或流产以及出生后第三天的新生儿甲状腺功能。
共有136名女性参与了本研究，其中68名患有甲状腺功能减退，68名妊娠情况正常。在孕20 - 24周时，甲状腺功能减退组与对照组胎儿甲状腺体积无显著差异（230.58±63.75mm³对230.15±75.69mm³，P = 0.98）；在孕28 - 32周时也无显著差异（491.55±154.88mm³对450.16±136.13mm³，P = 0.059）。此外，两组不良事件的发生率也相似。在调整混杂因素后，这些结果保持不变。
本研究结果表明，母亲甲状腺功能减退可能不会显著影响胎儿的HPT轴。然而，需要强调的是，这一结论仅基于甲状腺功能减退得到良好控制的母亲的数据。此外，在解释这一发现时应考虑明显临床甲状腺功能减退的低患病率。
