Effects of Thyroid Peroxidase Antibody on Maternal and Neonatal Outcomes in Pregnant Women in an Iodine-Sufficient Area in China

Abstract

Purposes. To evaluate the effects of thyroid peroxidase antibodies (TPOAb) on maternal and neonatal adverse outcomes in pregnant women. Methods. 208 pregnant women at 24-28 weeks were divided into two groups, TPOAb-positive and TPOAb-negative groups. Thyroid function and TPOAb were determined in all subjects until 12 months postpartum. Levothyroxine was supplemented to maintain euthyroid with periodical checking of thyroid functions. The prevalence of postpartum thyroiditis (PPT), placenta previa, placental abruption, premature rupture of membrane, postpartum haemorrhage, polyhydramnios, oligohydramnios, preterm birth, low birth weight, congenital hypothyroidism, and neonatal diseases were observed in two groups. Results. Of all women, 11.54% had a PPT. The prevalence of PPT was significantly higher in TPOAb-positive than TPOAb-negative group (42.31% versus 7.14%, P < 0.001), with 45.46% and 53.85% of PPT happening at 6 weeks postpartum in TPOAb-positive and TPOAb-negative groups. The incidence of polyhydramnios was significantly higher in TPOAb-positive than TPOAb-negative group (15.38% versus 2.74%, P = 0.02). Conclusion. Pregnant women with TPOAb-positive had increased risk of PPT, predominantly happening at 6 weeks postpartum. TPOAb was associated with increased incidence of polyhydramnios and the underlying mechanisms required further investigation. Earlier screening of thyroid function during pregnancy and postpartum was warranted in our region.

Figure 1

The flow diagram of the study process. PPT: postpartum thyroiditis.

Figure 2

Changes of TPOAb levels antepartum and postpartum in TPOAb-positive and TPOAb-negative groups. (a) Changes of TPOAb levels antepartum and postpartum in TPOAb-positive group; (b) changes of TPOAb levels antepartum and postpartum in TPOAb-negative group. ^∗ P < 0.01, TPOAb levels postpartum compared with antepartum in TPOAb-positive group.