Thyrozol Use In Pregnancy & Lactation

Women of childbearing potential: Women of childbearing potential have to use effective contraceptive measures during treatment.
Pregnancy: Hyperthyroidism in pregnant women should be adequately treated to prevent serious maternal and foetal complications.
Thiamazole is able to cross the human placenta.
Based on human experience from epidemiological studies and spontaneous reporting, thiamazole is suspected to cause congenital malformations when administered during pregnancy, particularly in the first trimester of pregnancy and at high doses.
Reported malformations include aplasia cutis congenita, craniofacial malformations (choanal atresia; facial dysmorphism), exomphalos, oesophageal atresia, omphalo-mesenteric duct anomaly, and ventricular septal defect.
Thiamazole must only be administered during pregnancy after a strict individual benefit/risk assessment and only at the lowest effective dose without additional administration of thyroid hormones. If thiamazole is used during pregnancy, close maternal, foetal and neonatal monitoring is recommended.
Lactation: Thiamazole passes into breast milk where it can reach concentrations corresponding to maternal serum levels, so that there is a risk of hypothyroidism developing in the infant.
Breast-feeding is possible during thiamazole treatment; however, only low doses up to 10 mg daily may be used without additional administration of thyroid hormones.
The function of the thyroid gland of the neonate has to be monitored regularly.