Hyperthyroidism complicating pregnancy:results of treatment by antithyroid drugs in 34 pregnancies - abstract

ABSTRACT

Thirty-four pregnancies (36 infants) complicated by hyperthyroidism were seen at the General Hospital, Port-of-Spain, and the Mount Hope Women's Hospital during a 6«-year period. This retrospective study was done to determine the foetal and maternal morbidity and mortality associated with hyperthyroidism in pregnancy. The best form of therapy, whether anti-thyroid drugs alone or in combination, is evaluated, comparing our findings with other series from the 1950s to the 1980s. Hyperthyroidism was diagnosed following conception in 6 pregnancies, and detection and treatment commenced in 28 before conception. Treatment was with carbimazole alone in 26 with modified dosages of 5 to 15 mg daily. Carbimazole and propranolol were used in seven, and propylthiouracil in one pregnancy. The total foetal loss was 18 per cent with a perinatal loss of 9 per cent. There were no premature deliveries but one abortion in the group treated with carbimazole alone. In pregnancies treated with carbimazole and propranolol, there were four premature deliveries ending with perinatal death (including one death due to congenital abnormalities) and a second trimester abortion of one set of twins. No infant had goitre. Twenty-five (86 per cent) of the surviving infants were above the 25th centile for gestational age. There was a relative excess of infants with premature labour and birth weight less than the 25th centile in the pregnancies with treatment beginning following conception. The complication of hyperthyroidism in pregnancy can be treated effectively with minimal doses of anti-thyroid drugs alone (AU)