Does first-trimester nuchal cord affect the blood flow in the ductus venosus? A prospective observational study

Main objective of the present study was to investigate the association between the presence of nuchal cord (NC) and the measurement of the ductus venosus pulsatility index for veins (ductus venosus (DV) PIV).

This was a prospective study of 1974 singleton pregnancies that underwent first-trimester screening at 11-13⁺⁶ gestational weeks. Color Doppler was used to demonstrate the presence of a NC in all cases and the DV PIV was calculated routinely, as part of the standard scan. The association between the presence of a NC and the DV PIV was then examined overall and at each gestational week.

A NC was demonstrated in 17.1% of cases. The incidence of nuchal cord was significantly higher at 13-13⁺⁶ weeks (24.7%, n = 119) compared to the one at 12-12⁺⁶ (16.5%, n = 192) and 11-11⁺⁶ weeks (7.9%, n = 26) (p < .001). No significant correlation was found between NC presence and DV PIV (p = .344). The DV PIV was 0.99 (± 0.15) for patients without NC versus 0.99 (± 0.15) for patients with NC (p = .34).

There was no association between the presence of a NC at 11-13⁺⁶ gestational weeks and the DV PIV.