Antithyroglobulin and Antiperoxidase Antibodies Can Negatively Influence Pregnancy Outcomes by Disturbing the Placentation Process and Triggering an Imbalance in Placental Angiogenic Factors.

Background/

Objectives

Thyroid autoimmunity (TAI) affects about 15% of women of reproductive age and can negatively affect pregnancy outcomes. One possible mechanism for pregnancy complications can be attributed to a disturbed process of placentation caused by thyroid antibodies. To test this hypothesis, placental hormones and angiogenic factors in pregnant women with TAI were evaluated.

Methods

Fifty-eight hypothyroid women positive for TPOAb/TgAb, thirty-three hypothyroid women negative for TPOAb/TgAb, and thirty-nine healthy controls were enrolled in this study. Maternal thyroid function tests were established every month throughout pregnancy, and angiogenic placental factors, pro-angiogenic placental growth factor (PlGF); two anti-angiogenic factors, soluble vascular endothelial growth factor receptor 1 (sFlt-1) and soluble endoglin (sEng); and placental hormones, estradiol, progesterone, and hCG, were determined during each trimester.

Results

Obstetrical and neonatal outcomes did not differ between the groups. However, several detrimental effects of thyroid antibodies were observed. These included a positive correlation between TgAb and the sEng/PlGF ratio in the first trimester and positive correlations between TPOAb and sFlt-1 and between TgAb and the sFlt-1/PlGF ratio in the third trimester. TgAbs in the first trimester was a risk factor for gestational hypertension and preeclampsia.

Conclusions

Our study indicates that TPOAbs and TgAbs can exert a direct harmful effect on placentation, leading to disturbances in the production of placental angiogenic factors and, consequently, to an increased risk of gestational hypertension and preeclampsia.