Effects of Thyroperoxidase Antibody and Thyroglobulin Antibody on Maternal and Neonatal Outcomes in Pregnant Women

The aim of the study was to evaluate the effects of thyroperoxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) on maternal and neonatal adverse outcomes in pregnant women. A total of 296 singleton pregnant women were classified into four groups according to the thyroid auto-antibody in the first trimester. Finally, there were 97 women in TPOAb positive group (TPOAb+/TgAb-), 35 in TgAb positive group (TPOAb-/TgAb+), 85 in TPOAb and TgAb positive group (TPOAb+/TgAb+), and 79 in TPOAb and TgAb negative group (TPOAb-/TgAb-). Thyroid function, TPOAb, and TgAb were checked during pregnancy and followed up at 6 weeks, 3 months, 6 months, 9 months, and 12 months postpartum. Levothyroxine sodium tablets could be taken to maintain euthyroid antepartum. Thyroid function of women with postpartum thyroiditis (PPT) were followed up at 2 and 3 years postpartum. We observed the incidence of PPT, premature rupture of membranes (PROM), placental abruption, placenta previa, polyhydramnios, oligohydramnios, postpartum hemorrhage, preterm birth, and low birth Weight in the four groups. 19.93% of the women had PPT. The incidence of PPT in TPOAb+/TgAb-, TPOAb-/TgAb+, TPOAb+/TgAb+groups was significantly higher than that in TPOAb-/TgAb- group, respectively (16.49 vs. 6.33%, 22.86 vs. 6.33%, 35.29 vs. 6.33%, p <0.05). The incidence of PPT in TPOAb+/TgAb+group was significantly higher than that in TPOAb+/TgAb- group (35.29 vs. 16.49%, p <0.01). PPT occurred as early as 6 weeks postpartum, but mainly at 3 and 6 months postpartum in the four groups (62.50%, 75.00%, 70.00%, 80.00%). All PPT in TPOAb-/TgAb- group occurred within 6 months postpartum, while it was found at 9 months or 12 months postpartum in other three groups. There was no classical form of PPT in TPOAb-/TgAb- group, while in the other three groups, all three types (classical form, isolated thyrotoxicosis, isolated hypothyroidism) existed. At 2 years postpartum of the women with PPT, the rate of euthyroidism in TPOAb+/TgAb+group was significantly lower than that in TPOAb-/TgAb- group (p <0.05). At 3 years postpartum of the women with PPT, the rate of euthyroidism in TPOAb+/TgAb-, TPOAb-/TgAb+, and TPOAb+/TgAb+groups were significantly lower than that in TPOAb-/TgAb- group (p <0.05). The values of TPOAb and TgAb postpartum were significantly higher than those during pregnancy (p <0.05). The incidence of PROM in TPOAb+/TgAb- group was significantly higher than that in TPOAb-/TgAb- group (32.99 vs. 17.72%, p <0.05). The binary logistic regression for PPT showed that the OR value of TPOAb was 2.263 (95% CI 1.142-4.483, p=0.019). The OR value of TgAb was 3.112 (95% CI 1.700-5.697, p=0.000). In conclusion, pregnant women with positive thyroid auto-antibodies had an increased risk of PPT and a reduced rate of euthyroidism at 2 and 3 years postpartum. TPOAb is associated with the incidence of PROM. Both of TPOAb and TgAb were independent risk factors for PPT. TgAb deserves more attention when studying autoimmune thyroid disease (AITD) combined with pregnancy.