Abstract

The relation of thyroid dysfunction with pregnancy loss is an increasingly attentive issue to many clinicians. A number of papers have shown a significant positive association between hypothyroidism, including subclinical hypothyroidism, and pregnancy loss. This has been thought to be due to a lower capacity of the thyroid to adapt to the changes in pregnancy. The authors aimed to examine the prevalence of subclinical and undiagnosed overt hypothyroidism in recurrent spontaneous abortions, late spontaneous abortions and stillbirths in our population.

The authors collected data retrospectively from the Pregnancy Loss Clinic database and supplemented this by review of perinatal deaths in 2008–2009. Women with sporadic spontaneous abortions, autoimmune disorders and optimally treated hypothyroidism were excluded.

262 women had thyroid function tests checked during investigation of pregnancy loss. Median maternal age was 35 (range 18–17). Subclinical and undiagnosed overt hypothyroidism were found in 11.45% of women. Twenty-two (22/262, 8.39%) had subclinical hypothyroidism, five (5/262, 1.91%) had undiagnosed overt hypothyroidism, and three (3/262, 1.15%) had known hypothyroidism, suboptimally controlled. Median T4 was 15.20 (range 7.3–23.8), and median TSH was 1.74 (range of 0.03–73.09). Thyroid-peroxidase antibodies were checked in two patients, which were raised in one patient with subclinical hypothyroidism. Three patients in the hypothyroid group were diagnosed with fetal abnormalities including anencephaly and cystic hygroma.

A significant number in this group of patients had hypothyroidism. However, due to ongoing controversies with thyroid function and pregnancy, the question of whether universal screening and subsequent treatment is appropriate remains to be answered.