EP09.56: The influencing factors of displaying fetal pulmonary veins by 2D and STIC combine HDFI techniques at 11–13⁺⁶ weeks

To assess the feasibility and usefulness of transabdominal 2D ultrasound and STIC combine with HDFI techniques for detecting the fetal pulmonary veins (PVs) in 11-13+6 W and find the influencing factors. 337 normal singleton fetuses were enrolled in this study. The abilities of 2D-HDFI and STIC-HDFI to display fetal PVs were compared. The display rates of 0, 1 PV, 2, 3 and 4 PVs for 2D-HDFI and STIC-HDFI were 0% and 3.6%, 9.5% and 31.2%, 58.5% and 55.5%, 30.3% and 9.8%, 1.8% and 0%, respectively. The display rate of 2D-HDFI method was higher than STIC HDFI method in each gestational age group and the total group (all P < 0.01). The fetal PVs display rate increased with the gestational age. In the 2D-HDFI group, only fetal CRL had a statistically significant effect on fetal PVs display (P < 0.01), maternal age, maternal BMI, history of pregnancy, history of lower abdominal surgery, placenta location, types of four-chamber view and fetal movements had no statistical significance on fetal PVs display (0.150≤P≤0.913); in the STIC-HDFI group, the influence of maternal BMI, fetal CRL and fetal movements on fetal PVs display was statistically significant (all P < 0.01), maternal age, history of pregnancy, history of lower abdominal operation, placenta location and types of four-chamber view had no statistical significance on fetal PVs display (0.291≤P≤0.988). Both the real-time 2D-HDFI and STIC-HDFI methods adopted in this study had high display ability for fetal PVs in early pregnancy (11-13+6 W), the real-time 2D-HDFI method has better display ability and fewer influencing factors, and it may be used to detect PV anomalies early. Although the display ability of STIC-HDFI method is slightly poor and there are many influencing factors, it has the advantages of lower acquisition time than the real-time 2D technology, reduced exposure time to fetuses, post-processing of images, display in any slice, and remote transmission to expert consultation, etc. It can be used as a complement to two-dimensional sonography.