Influence of thyroid function on the fetal fraction during second trimester of pregnancy / 中华医学遗传学杂志

ABSTRACT

OBJECTIVE@#To assess the influence of thyroid function on the fetal fraction (FF) during the second trimester of pregnancy.@*METHODS@#A total of 1 861 pregnant women undergoing non-invasive prenatal testing (NIPT) and thyroxine function testing at 12 ~ 26 gestational weeks at the Affiliated Suzhou Hospital of Nanjing Medical University/Suzhou Municipal Hospital from January 2016 to December 2020 were selected as the study subjects. Univariate analysis and multivariate regression models were used to assess the correlation between free thyroxine 4 (FT4) levels and FF.@*RESULTS@#Univariate linear regression analysis indicated that the FF is correlated to the level of FT4 (b = 0.035, P < 0.001). The median fetal FF was 10.78% (IQR 8.2%, 13.82%), and this has increased along with the level of FT4 from 10.58% at <= 12.0 pmol/L to 11.77% at > 16.0 pmol/L. After further adjustment of gestational age and body mass index (BMI), the FF showed an increase trend along with the increase of FT4 levels, and a trend test also showed a statistical significance (Ptrend < 0.001).@*CONCLUSION@#Maternal FF can be affected by the level of free thyroxine during the second trimester of pregnancy.