The Nuchal Cord Conundrum: Understanding and Addressing Umbilical Entanglement in the Third Trimester of Pregnancy.

Better understanding of and addressing umbilical entanglement in the third trimester of pregnancy is necessary to estimate its impact on fetal circulation. An analysis of single physiological pregnancies wrapped with one or two coils of the umbilical cord around the neck makes it possible to understand the severity of the problem and distinguish it from perinatal umbilical strangulation. In an echocardiographic study performed at 32.1 weeks of pregnancy in fetuses with one and two coils of the umbilical cord around the neck, the pulsatility index (PI) and the Tei index for the left (Tei LV) and right ventricle (Tei RV) of the heart were measured to evaluate cardiac function. The study showed significantly higher Tei RV and Tei LV for fetuses with one (93 cases) and two coils of the umbilical cord around the fetal neck (26 cases) with respect to the control group of fetuses (680 cases) with no umbilical cord around the fetal neck, whereas PI UMBA did not differ significantly. Wrapping of the umbilical cord around the fetal neck may affect the study of the fetal heart without any mechanically induced compression of the umbilical vessels in normal pregnancy.