Nuchal cord type A and type B

Prenatal color Doppler sonographic evaluation of nuchal encirclement by the umbilical cord

“…The spectral Doppler findings represent increased downstream resistance and may appear before the onset of adverse and potentially irreversible effects on the fetus. 3,6,[10][11][12]18,19 However, in this series, we observed no fetal MCA or UA Doppler flow velocimetry changes in fetuses with NC that could be related to impaired blood flow in a compressed umbilical cord. This finding indicates that if the cord compression is not prolonged, fetal blood flow is not impaired and the fetus can maintain tissue oxygenation through its reserve.…”

“…Compression of involved vessels can occur in cases of NC, and Doppler flow velocimetry may detect impaired or increased downstream resistance (reflecting increasing cord compression) before the onset of adverse and potentially irreversible effects on the fetus. 6,[10][11][12] To date, most perinatal studies of NC have focused on the fetal hypoxia that occurs during delivery. [6][7][8]13,14 A review of the general medical literature reveals few published studies of the effects of NC in utero.…”

Sonographic assessment of the umbilical cord

“…4 Similarly, long cords in excess equal and above 70 cm in length are described in association with fetal entanglement, true knots, torsion and prolapse. 9 Therefore, it would be very important to develop means of ultrasound assessment of cord length. Up to date, there are few studies that measured umbilical cord length in first and second trimester of pregnancy.…”

Umbilical Cord Entanglement: Diagnostic and Clinical Repercussions

“…Cord entanglements can be classified according to the following: 48 • Their nature (tight or loose) • Number of loops (simple, double, triple or multiple) • Location (neck, body, extremities or mixed).…”