methimazole and Birth-Weight

Hyperthyroidism can occur during pregnancy and the postpartum period, and the treatment of hyperthyroidism should be considered in the preconception phase. Pregnancy has multiple normal physiologic effects on thyroid hormone, which is a separate process distinct from syndromes such as transient hyperthyroidism of hyperemesis gravidarum. The rationale regarding antithyroid drug use during different stages of pregnancy is reviewed, including the literature regarding adverse neonatal outcomes such as aplasia cutis and methimazole embryopathy in the setting of first trimester maternal methimazole use. The use of treatment modalities for hyperthyroidism during pregnancy such as surgery is also discussed. Studies of maternal, fetal, and neonatal complications of hyperthyroidism are examined in this article. Moreover, the evidence regarding antithyroid drugs, specifically methimazole and propylthiouracil, during lactation is considered. Other disease conditions that can take place during pregnancy and the postpartum period such as hyperemesis gravidarum, subclinical hyperthyroidism, gestational trophoblastic disease, and postpartum thyroiditis and their treatments are also presented.

Topics: Antithyroid Agents; Birth Weight; Female; Humans; Hyperthyroidism; Infant, Newborn; Methimazole; Postpartum Period; Preconception Care; Pregnancy; Pregnancy Complications; Premature Birth; Propylthiouracil; Risk; Thyroid Hormones

Topics: Adolescent; Adult; Birth Weight; Female; Fetal Death; Humans; Hyperthyroidism; Infant; Infant Mortality; Infant, Newborn; Infant, Premature; Methimazole; Pregnancy; Pregnancy Complications; Propylthiouracil; Thyroid Function Tests; Thyroid Hormones

With regard to their thyroid function, somatic and intellectual development, we compared 17 children of 13 hyperthyroid mothers (group I) receiving antithyroid drug treatment during their pregnancies with 25 children of 15 mothers who were euthyroid without any antithyroid treatment during their pregnancy (group II). Mean duration of maternal treatment was 3.5 months in group I, using carbimazole or thiamazole (N = 12) and propylthiouracil (N = 1). Age at examination in group I was 7.2 +/- 6.2 years, in group II 8.7 +/- 7.1 years (mean +/- SD). Both groups showed no significant differences in the results of the clinical examination and in the degree of their mental and psychomotoric development at the time of study. We found the mean birth weight of the infants in group I significantly lower than in group II (3165 +/- 339 vs 3666 +/- 670 g, p less than 0.03). The individual birth weights, however, were normal for gestational age. The body weight difference between groups disappeared during the further somatic development of the children. The serum concentration of free thyroxine in group I was significantly higher than in group II (17.2 +/- 2.4 vs 14.9 +/- 1.9 pmol/l, p less than 0.003), but fell in both groups within the normal range. The evaluation of the psychomotoric and intellectual capacity of the children at different developmental stages showed no abnormalities detectable by our tests. Thus, in the children of the two groups we found no adverse effects of a maternal antithyroid drug treatment during pregnancy or of inactive maternal Graves' disease alone, neither on thyroid gland size and function nor on the physical or intellectual development, after the neonatal period.

Topics: Birth Weight; Carbimazole; Child; Drug Therapy, Combination; Female; Follow-Up Studies; Graves Disease; Growth; Humans; Infant, Newborn; Intelligence; Maternal-Fetal Exchange; Methimazole; Pregnancy; Pregnancy Complications; Prenatal Exposure Delayed Effects; Propylthiouracil; Thyroid Gland; Thyrotropin; Thyroxine; Triiodothyronine