Feasibility of fetal portal venous system ultrasound assessment at the first-trimester anomaly scan.

Objective. The main objective of our study was to demonstrate the potential of the first-trimester anomaly scan to identify components of the portal venous system (PVS), and to describe the potential of microscopic evaluation of the PVS in the FT. Materials and method. We evaluate the appearance of PVS in 200 scan examinations performed in fetuses between 12 and 13.6 gestational weeks (GW). The scans were performed in half of the cases by two operators who had extensive experience in obstetric ultrasound (Group I) and in the other half of the cases by two sonographers with less experience (Group two). The examinations were performed via transabdominal and, in selected cases, via transvaginal approaches. We performed macroscopic and microscopic examination of the liver in one case of interrupted pregnancy. Results. Group I successfully assessed all PVS features by transabdominal approach in 27% of the cases. The assessment rate was lower for Group II (14%). The transvaginal approach or reschedule showed a better rate of detection for both groups (88% in Group I and 72% in Group II). Unfavorable fetal position, BMI greater than 24, abdominal scar, retroverted uterus, fibroids and combinations of the above were reasons for the reschedule or using the transvaginal approach. Following reevaluations, the rate of detection of the L-shaped UV confluence increased from 91% to 98% in Group I, and from 79% to 95% in Group II, on transabdominal approach. The visualization of a normal L-shaped UV confluence, that excludes major PVS abnormalities, is achievable in approximately 80% of cases, regardless the examiners experience. The microscopic examination confirmed the normal aspect of portal venous system. Conclusions. Early fetal PVS assessment is feasible. The experience of the sonographer, uterus anomalies or the Body Mass Index (BMI) may be factors that affect the rate of detection. Combining the abdominal and vaginal approach or rescanning, a higher rate can be achieved. The first-trimester pathology can be performed only microscopically. [ABSTRACT FROM AUTHOR]