Abnormal first-trimester ductus venosus blood flow: a risk factor for adverse outcome in fetuses with normal nuchal translucency.

OBJECTIVES

First-trimester nuchal translucency thickness (NT) is a potent tool for assessment of fetal risks of aneuploidy and other adverse outcomes. When NT is increased, Doppler assessment of the ductus venosus (DV) enhances the prediction specificity for Down syndrome. This study assessed abnormal Doppler DV waveform as a predictor of adverse outcome when the NT is normal.

METHODS

This was a case-control study of 2,505 consecutive patients undergoing NT screening in our certified first-trimester screening program. First-trimester Doppler assessment of DV was performed and atrial systolic velocity was rated as antegrade (normal) or absent/reversed (DV-RAV; abnormal). Each case with normal NT (< 95(th) percentile) and DV-RAV was matched with two controls with respect to maternal age within 1 year, NT within 0.2 mm, crown-rump length within 3 mm, and closest calculated aneuploidy risk. Outcomes for paired variables were compared using t-test and Chi-square test.

RESULTS

Forty-seven (1.9%) patients had normal NT and DV-RAV. After exclusion of three cases with obvious first-trimester anomalies and two with incomplete outcome data, 42 remained for analysis. Adverse outcome included cardiovascular defects (n = 6), fetal growth restriction (n = 3), renal anomaly (n = 2), aneuploidy (n = 3) and multiple defects (n = 3), in a total of 11/42 cases (26.2%). Cardiac abnormalities, renal abnormalities and perinatal death were all significantly more common in the study group (all P < 0.05).

CONCLUSIONS

Abnormal first-trimester DV Doppler findings appear to predict adverse outcome independently of a normal NT. These patients need detailed mid-trimester assessment of fetal anatomy with formal echocardiography, and subsequent follow-up.