Takeshi Maruo

The Role of Thyroid Hormone in Trophoblast Function, Early Pregnancy Maintenance, and Fetal Neurodevelopment

OBJECTIVEnTo review the literature on the roles of thyroid hormone in trophoblast function, early pregnancy maintenance, and fetal neurodevelopment.nnnMETHODSnMEDLINE was searched for English-language papers published from 1971 to 2003, using the key words brain, hypothyroidism, placenta, pregnancy, threatened abortion, thyroid hormone, thyroid hormone receptor, thyroid hormone replacement therapy, thyroid hormone-responsive gene, and trophoblast.nnnRESULTSnTransplacental transfer of thyroid hormone occurs before the onset of fetal thyroid hormone secretion. Thyroid hormone receptors and iodothyronine deiodinases are present in the placenta and the fetal central nervous system early in pregnancy, and thyroid hormone plays a crucial role both in trophoblast function and fetal neurodevelopment. Maternal hypothyroxinemia is associated with a high rate of spontaneous abortion and long-term neuropsychological deficits in children born of hypothyroid mothers. Maternal iodine deficiency also causes a wide spectrum of neuropsychological disorders in children, ranging from subclinical deficits in cognitive motor and auditory functions to hypothyroid-induced cognitive impairment in infants. However, these conditions are preventable when iodine supplementation is initiated before the second trimester. Although thyroid hormone replacement therapy is effective for reducing the adverse effects complicated by maternal hypothyroidism, the appropriate dose of thyroid hormone is mandatory in protecting the early stage of pregnancy.nnnCONCLUSIONSnClose monitoring of maternal thyroid hormone status and ensuring adequate maternal thyroid hormone levels in early pregnancy are of great importance to prevent miscarriage and neuropsychological deficits in infants.

Effects of Combined Estriol/Pravastatin Therapy on Intima-Media Thickness of Common Carotid Artery in Hyperlipidemic Postmenopausal Women

Background: Several studies show that 17β-estradiol (E2) has protective effects on atherosclerosis in the arterial wall in postmenopausal women. Little information is, however, available regarding the effect of estriol (E3) on atherosclerosis. This study was conducted to investigate the effects of E3 alone and combined E3/pravastatin therapy on intima-media thickness (IMT) of common carotid artery in postmenopausal women. Methods: Thirty-three postmenopausal women were allocated to four groups: daily treatment with E3 (2 mg) alone (E3 group, n = 10), pravastatin (10 mg) alone (pravastatin group, n = 6), combined treatment with E3 (2 mg) and pravastatin (10 mg; E3/pravastatin group, n = 7) and untreated control group (n = 10). All women attended the Kobe University Hospital once a year for routine gynecological and ultrasonographic examinations for the evaluation of atherosclerosis. Results: A significant decrease in IMT was noted in the E3/pravastatin group compared with that in the untreated control group (p < 0.05), whereas there was no significant difference in the reduction rate of IMT in the pravastatin group, E3 group and untreated control group. Conclusions: The combined E3/pravastatin therapy appeared to retard the progression of atherosclerosis in postmenopausal women.