A reference for ductus venosus blood flow at 11-13+6 weeks of gestation.

OBJECTIVE: To establish reference ranges for ductus venosus (DV) blood flow assessment obtained transabdominally at 11-13(+6) weeks of gestation.

METHODS: A cross-sectional study was conducted on singleton pregnancies with a crown-rump length (CRL) ranging from 45 to 84 mm, normal fetus, and subsequent newborn birth weight appropriate for gestational age. Measurements of DV Doppler variables were performed by experienced sonographers: peak velocity during ventricular systole (S-wave) and diastole (D-wave), nadir during atrial contraction (A-wave), time-averaged maximum velocity (TAmax), pulsatility index for veins (PIV), and peak velocity index for veins (PVIV).

RESULTS: A total of 304 fetuses were included. The mean CRL was 60.7 ± 7.2 mm (range: 45.9-75.5). The mean nuchal translucency measurement was 1.4 ± 0.4 mm. The S-wave, D-wave, A-wave, and TAmax values varied significantly with gestational age (p < 0.05) and regression models were constructed for each variable. The remaining variables, systolic/atrial wave ratio, preload index, PVIV, and PIV, did not vary significantly with gestational age within this CRL range.

CONCLUSION: Reference ranges for DV Doppler assessment were established in normal fetuses. These ranges may be a useful tool for evaluation of anueploidy and fetal cardiac function.