[Diagnostic and therapeutic problems in thyrotoxic crisis in pregnant women. Influence of treatment on life and health of fetus and infant].

Thyrotoxic crisis during pregnancy is a rare condition, but because of the danger it poses for the mother and fetus, every physician should be able to diagnose and treat it. When not recognized or incorrect treated hyperthyroidism, which is not easy to diagnose during pregnancy, is usually the basis for thyrotoxic storm. Serious conditions such as Graves' disease or multinodular goiter have to be distinguished from transient hyperthyroidism. Symptoms, such as: heat intolerance, hyperexia, emesis, tachycardia, increased pulse pressure and emotional liability should be considered cautiously because they are characteristic both for hyperthyroidism and for pregnancy. Interpretation of laboratory results need to take physiological changes during pregnancy into account--during the first trimester a low TSH serum concentration should be expected, whereas in the third trimester the free thyroxine (fT4) concentration decreases. Some conditions characteristic for pregnancy may be causative for thyrotoxic crisis: preeclampsia, placenta previa, labour induction, labour and cessarian section. Usually a hypermetabolic state has a characteristic, severe course but the possibility of monosystemic presentation must be kept in mind, because it is difficult to diagnose. Management of thyrotoxic crisis includes specific (thyrostatic agents, iodine preparations, adrenolytics, plasmaferesis) and supportive treatment. Thyrostatic agents (thiamazole and propylthiouracyl) can cross the placental barrier and similarly to iodine preparations can interfere with the pituitary-thyroid axis of the fetus. Additionally, thiamazole may cause specific embryopathy and should be considered as a second-line treatment. Adrenolytics affect the placental and uterine functions, and in high doses causes newborn hypoglycemia and bradycardia. A surgical approach is linked to an increased rate of preterm labour and miscarriage, but long-term effects are good.