First trimester fetal ultrasonographic soft markers and adverse pregnancy outcomes

Objective: To evaluate the relationship between first trimester (11 ~ 13 + 6 gestational weeks) ultrasonographic soft markers (USMs) and fetal adverse pregnancy outcomes. Methods A retrospective study, singleton pregnancies were recruited from the first-trimester scanning (FTS) during May 2017 to August 2021 at the Affiliated Suzhou Hospital of Nanjing Medical University. All fetuses were followed up till birth or induced abortion. The spectrum and detection rate of USMs during the first trimester were studied. The correlation between USMs and adverse pregnancy outcomes was analyzed to evaluate the management of fetus with 1st trimester USMs. Results Among 7355 fetuses who underwent FTS, 6868 fetuses with complete follow-up outcomes were recruited in the study. Total 1105 USMs were reported among 963 fetuses during the first trimester. According to the detection rate, the most frequently detected USMs were increased nuchal translucency (NT) thickeness (6.70%, 460/6868), followed by echogenic intracardiac focus (EIF) (5.10%, 350/6868), absent/reversed a-wave of ductus venosus (1.35%, 93/6868) and absence/hypoplasia of the nasal bone (NB) (1.03%, 71/6868). The incidence of adverse pregnancy outcomes in fetuses with two or more USMs was 36.44% (43/118), which was significantly higher (χ2 = 114.50, P  < 0.001) than fetuses with single USM (5.68%, 48/845). The incidence of adverse pregnancy outcomes in fetuses who had both USMs and structural abnormalities was 72.60% (53/73), were also significantly higher (χ2 = 368.17, P  < 0.001) than fetuses with isolated USMs without structural abnormalities (4.27%, 38/890). Logistic regression analysis showed increased NT thickness, absence/hypoplasia of the NB, absent/reversed a-wave of ductus venosus, tricuspid regurgitation (TR), choroid plexus cyst (CPC), echogenic bowel (EB) and single umbilical artery (SUA) were closely associated with the adverse pregnancy outcomes ( P  < 0.05). However, there was no significant correlation between EIF, mild pyelectasis (PYE) and fetal adverse pregnancy outcomes ( P  = 0.30; P  = 0.77). Conclusions The ultrasonographic soft markers found during the first trimester, especially multiple USMs, or USMs are associated with structural malformations, are potential soft markers in predicting fetal adverse pregnancy outcomes.