Color ultrasonography: a useful technique in the identification of nuchal cord during labor

Objective To compare the accuracy of intrapartum ultrasound with and withou t color Doppler for identification of nuchal cord displacement during labor . Methods 180 normal pregnant women, admitted in labor, or for induction to l abor, were examined independently by two researchers, using either conventi onal realtime gray-scale imaging or color Doppler imaging. A repeat examina tion was performed by the other researcher using the other ultrasound modal ity. Nuchal cord displacement was classified as either negative, definite o r suspicious. Nuchal cord at birth was classified as either tight or loose. Results Sixty-two (34%) cases examined using the two ultrasound imaging mod alities presented with nuchal cord at delivery. The sensitivity of color Do ppler was 96.8%. The accuracy of color Doppler in detecting nuchal cord dur ing labor was significantly better (P < 0.05) than gray-scale imaging alone . The results of a restricted sequential t-test analysis of 53 un-tied pair s showed an overall preference in favor of color Doppler assessment: statis tical significance (P < 0.01) was reached after 41 un-tied pairs. Conclusions The tight and loose nuchal cord could not be distinguished by u ltrasound. Color Doppler imaging can provide useful additional information to gray-scale imaging in the detection of nuchal cord displacement during l abor.