Fifty-one pregnancies in 41 patients with Graves' disease (1.24 per pa
tient) were studied. Mean age was 29+/-5 years. Eighty-five per cent o
f patients were married; 51% were pauciparous; 90% resided in urban or
semiurban areas; and 69% were in the low or middle income brackets. S
ymptoms of Graves' disease were present before the pregnancy in 86% of
cases. The gestational age at which the diagnosis of the thyroid diso
rder was established did not influence the frequency of the main manif
estations; thyrotoxicosis was seen in over half the cases. The hyperth
yroidism worsened during the pregnancy and Improved to some extent aft
er delivery. From the prepregnancy period to the postpartal period, th
e proportion of patients under carbimazole fell from 75% to 30%, and t
he dose of the drug decreased from 26 to 18 mg/d. Data on the outcome
of the pregnancy were available for 35 cases; there were 65% full-term
births, 20% premature births, and 14% abortions. Toxemia of pregnancy
was seen in 14% of cases. Of the 39 delivered infants, 58% were healt
hy, 15% were stillborn, 5% were growth-retarded, 5% had macrosomia, an
d 2% had birth defects; abortion occurred in 12% of cases. Factors ass
ociated with an increased risk of premature delivery (maximum rate 43%
) were residence in a semiurban or rural area, low income, unmarried s
tatus, young age of the mother, a short time interval between onset of
Graves' disease and the pregnancy, failure to diagnose Graves' diseas
e until after the pregnancy, poor thyroid function control with a slow
heart rate or severe tachycardia; and absence of use of carbimazole.
These same factors were predictive of maximal rates of fetal wastage (
20% to 100%), intrauterine growth retardation (12.5% to 25%), and stil
l-birth (15 to 50%).