Effect of thyroid dysfunction and autoimmunity on pregnancy outcomes in low risk population

The objective of this study was to assess the effect of thyroid dysfunction and autoimmunity in early pregnancy on adverse pregnancy and neonatal outcome.

497 pregnant women between 10 and 12 gestational age were invited who were attending for their first antenatal visit and asked to perform blood tests for thyroid function and antithyroid peroxidase antibodies. A total of 395 women were recruited in the present study. Cases were classified into four groups according to thyroid function and anti-TPO results. The pregnancy outcomes included gestational diabetes mellitus, preeclampsia, preterm delivery, cesarean rate, small for gestational age, low birth weight.

2.5-(OR 2.5, 95% CI 1.06-5.89) and 4.8-(OR 4.85, 95% CI 1.89-12.42) fold increase in preterm delivery was detected in groups with isolated anti-TPO positivity and subclinic hypothyroidism with anti-TPO positivity compared to reference group, respectively. No association was found between thyroid dysfunction and anti-TPO positivity with gestational diabetes, preeclampsia, cesarean rates, low birth weight and small for gestational age neonates.

Pregnant women with anti-TPO antibody positivity alone or with subclinic hypothyroidism were more likely to experience a spontaneous preterm delivery.