[Nuchal cord between 37 and 42 completed weeks of gestation--diagnosis and prognostic value]

To investigate the ability of transabdominal ultrasound to detect nuchal cord(s) between 37 and 42 completed weeks of gestation (w.g.) and to assess its prognostic value in relation with the perinatal outcome.

Transabdominal ultrasound examination using gray-scale and color Doppler imaging was performed in 86 singleton pregnancies between 37 and 42 completed w.g. in a prospective study. In 36 cases the presence of nuchal cord(s) was suspected. Nuchal cords were classified as with one, two or three loops. The outcome of labor and delivery was obtained from hospital records.

The sensitivity of ultrasound for the presence of single-loop nuchal cord was 68.1%, while the specificity, positive and negative predictive value was 77.2%, 53.5% and 86.3%, respectively.

The sensitivity and specificity of transabdominal ultrasound in diagnosing single-loop nuchal cord between 37 and 42 w.g. is relatively high. However, the detection rate for multiple loops of nuchal cord is even higher. Single-loop nuchal cords are not associated with increased risk of Cesarean section or vaginal instrumental delivery.