Gestational thyrotoxicosis during a triplet pregnancy.

摘要

Human chorionic gonadotropin (hCG) levels are highest at 10 weeks' gestation in normal pregnancy and free thyroxine increases slightly at the same time. Circulating hCG with higher biological activity or higher hCG level causes clinical thyrotoxicosis in some cases of hyperemesis gravidarum. We report a woman who developed gestational thyrotoxicosis during triplet pregnancy.The patient was 34 years old and had been sterile for the past 8 years since marriage. In this period, she had undergone five homologous artificial inseminations, and one in-vitro fertilisation and embryo transfer (IVF-ET), all of which failed. A second IVF-ET led to the successful implantation of three embryos. Hyperemesis appeared at 6 weeks' gestation, and the patient complained of palpitation and headache, as well as having a decreased body weight of 8 kg (14%) at 9 weeks' gestation. Laboratory data at 12 weeks' gestation showed hyperthyroidism as follows: free T4 (FT4), 5.73 ng/dl; free T3, (FT3) 15.62 pg/ml; and TSH, < 0.003 /ilU/ml. The levels of serum TSH receptorantibodies, thyroid-stimulating antibodies, thyroxin-binding globulin and antithyroid microsomal antibody were 3%, 154%, 35.1 mg/dl and <100, respectively, all of which were within the respective reference ranges. She had neither goitre nor exophthal-mus. Total hCG-beta subunit (total hCG-beta) that measures both intact hCG and free hCG-beta subunit was 359,900 mlU/ml (the reference range between 12 and 20 weeks' gestation is 5,375-182,766 mlU/ ml). Vomiting, palpitation, and headache did not resolve even beyond 12 weeks' gestation. Daily oral Lugol's solution (30 mg as inorganic iodine) was administered from 13 weeks' gestation. This alleviated the symptoms and reduced FT4 and FT3 to 2.36 ng/dl and 5.76 pg/ml, respectively, in 1 week (Figure 1). Shirocker's operation was performed at 14 weefc' gestation. Total hCG-/? decreased to 190,000 mlU/ml, and vomiting and palpitations disappeared at 15 weeks' gestation. Lugol's solution was discontinued at 19 weeks' gestation when total hCG-beta, FT4, andiFT3 decreased to 99,200 mlU/ml, 1.65 ng/dl and 4.18 pg/ml, respectively. After cessation of inorganic iodine, FT4 and FT3 increased transiently to 2.49 ng/dl and 5.36 pg/ml, respectively, while total hCG-beta remained at around 80,000 mKj/ml (the reference range between 21 and 40 weeks' gestation is 3,464-71,465 mlU/ml).