Outcome of pregnancy complicated by thyroid dysfunction in Iran
Morteza Taghavi, Nafiseh Saghafi & Shirin Saber
Objective: Maternal thyroid hormone excess or deficiency has been associated with adverse health outcomes for both the mother and child. This study performed to study the prevalence of thyroid disorders and its effect on pregnancy outcome in pregnant women.
Methods: Five hundred pregnant women in first trimester of pregnancy were enrolled in the study. Serum Thyrotropin (TSH), Free T4 (FT4), and Free T3 (FT3) were measured by high-sensitive radioimmunoassay. Overt hyperthyroidism was diagnosed when both TSH was suppressed and FT4 or FT3 was elevated. Subclinical hyperthyroidism was diagnosed when TSH was suppressed with normal FT4 and FT3. The diagnostic criteria for overt hypothyroidism was TSH > 4 mU/l accompanied by decreased FT4, and for subclinical hypothyroidism was TSH > 4 mU/l with normal FT4 level.
Those with thyroid disorders referred to an Endocrinologist for medical treatment and all subjects were followed until delivery.
Results: Hypothyroidism found in 49 (9.8%) women (subclinical hypothyroidism: 7.4%, overt hypothyroidism: 2.4%). Overt hyperthyroidism found in 3 (0.6%) women. Subclinical hyperthyroidism occurred in 21 (4.2%) women and considered as physiologic changes of pregnany. Nighteen women (3.8%) had preterm labor.
Out of 25 (5%) women developed pre-eclampsia. There was no significant difference in the incidence of preterm labor and pre-eclampsia in pregnant women with and without thyroid dysfunction.498 women delivered normal neonates and 2 (0.4%) mother delivered fetus with anomaly, but these mothers were euthyroid.
Conclusions: Thyroid dysfunction is common in pregnant women. The prevalence complications were not greater in patients with thyroid dysfunction.