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.