Department of Obstetrics and Gynecology, Akita University Hospital, 1-1-1 Hondo, Akita, 010-8543, Japan.
Perinatal Medical Center, Japanese Red Cross Akita Hospital, Akita, Japan.
BMC Pregnancy Childbirth. 2020 Jun 3;20(1):344. doi: 10.1186/s12884-020-03035-2.
Approximately 10% of all Graves' disease cases are triiodothyronine (T3)-predominant. T3-predominance is characterized by higher T3 levels than thyroxine (T4) levels. Thyroid stimulating hormone receptor autoantibody (TRAb) levels are higher in T3-predominant Graves' disease cases than in non-T3-predominant Graves' disease cases. Treatment with oral drugs is difficult. Here, we report a case of fetal goiter in a pregnant woman with T3-predominant Graves' disease.
A 31-year-old woman had unstable thyroid function during the third trimester of pregnancy, making it impossible to reduce her dosage of antithyroid medication. She was admitted to our hospital at 34 weeks of gestation owing to hydramnios and signs of threatened premature labor, and fetal goiter (thyromegaly) was detected. The dose of her antithyroid medication was reduced, based on the assumption that it had migrated to the fetus. Subsequently, the fetal goiter decreased in size, and the hydramnios improved. The patient underwent elective cesarean delivery at 36 weeks and 5 days of gestation. The infant presented with temporary symptoms of hyperthyroidism that improved over time.
The recommended perinatal management of Graves' disease is to adjust free T4 within a range from the upper limit of normal to a slightly elevated level in order to maintain the thyroid function of the fetus. However, in T3-predominant cases, free T4 levels may drop during the long-term course of the pregnancy owing to attempts to control the mother's symptoms of thyrotoxicosis. Little is known about the perinatal management and appropriate therapeutic strategy for T3-predominant cases and fetal goiter. Therefore, further investigation is necessary.
约 10%的 Graves 病病例为三碘甲状腺原氨酸（T3）优势型。T3 优势型的特点是 T3 水平高于甲状腺素（T4）水平。T3 优势型 Graves 病患者的甲状腺刺激激素受体自身抗体（TRAb）水平高于非 T3 优势型 Graves 病患者。口服药物治疗较为困难。在此，我们报告一例 T3 优势型 Graves 病孕妇胎儿甲状腺肿病例。
一名 31 岁女性在妊娠晚期甲状腺功能不稳定，无法减少抗甲状腺药物的剂量。她因羊水过多和早产先兆在妊娠 34 周时被收入我院，并且发现胎儿甲状腺肿（甲状腺肿大）。考虑药物已转移至胎儿，因此减少了她的抗甲状腺药物剂量。随后，胎儿甲状腺肿缩小，羊水增多的情况也有所改善。患者在妊娠 36 周零 5 天行择期剖宫产。婴儿出现短暂的甲亢症状，随着时间的推移逐渐改善。
Graves 病的推荐围产期管理是将游离 T4 调整至正常上限至轻度升高范围内，以维持胎儿的甲状腺功能。然而，在 T3 优势型病例中，由于试图控制母亲的甲亢症状，游离 T4 水平可能会在妊娠的长期过程中下降。对于 T3 优势型病例和胎儿甲状腺肿的围产期管理和适当的治疗策略知之甚少。因此，需要进一步研究。
