[Immunological abortion: the thyroid factor]

Spontaneous miscarriage (SM) is a multifactorial problem involving several couples. Recent studies investigated the correlations between the presence of antithyroid antibodies (ATA) and pregnancy loss, and found that many women with a previous history of recurrent miscarriage, showed high levels of ATA circulating in their blood. Further-more, the thyroid function disorder may also affect the course of pregnancy. Basically, two theories can explain the reasons of the spontaneous termination of pregnancy in presence of ATA: the first theory suggests that the hypofertlity or infertlity of these subjects may be due to a subtle degree of hypothyroidism which is difficult to detect by routine serum hormone determinations; the second theory supports that the presence of thyroid antibodies reveals a more generalized underlying abnormal stimulation of the immune system. Therefore, the thyroid function should be tested before conception and during pregnancy to avoid the pregnancy loss and neuropsychological deficits in infants. Actually, some papers suggest that treatments reserved to women with thyroid antibodies could decrease the miscarriage rate. Unfortunately, there is not agreement about the most effective therapy. We need more large, randomised, placebo controlled, double blind studies.