On pulse-wave Doppler, the systolic to diastolic ratio was normal at 2.5. As far as we could assess, this was a Type A looping (see below). The presentation was cephalic and the placenta’s location fundal. Since there was no other reason for the presence of variable decelerations and decreased fetal movement, we concluded that the baby was strangling himself as he was pulling on the cord, causing frequent cord compression.

Indications for induction of delivery included a poor biophysical profile score, a non-reactive stress test, and the nuchal cord. The patient was delivered at 39 weeks and 2 days gestational age. A C-section was performed and the prenatal diagnosis confirmed. The 2290g male baby had Apgar scores of 9/9 at 1 and 5 minutes, and did not require any special care at the nursery. The infant was discharged home the next day.

Discussion

Historical perspective

The assumption that nuchal cord entanglement could cause cord compression and thus intrapartum complications is not recent. In 1896, Gould mentioned Hippocrates’ references[2] on nuchal cord. Hippocrates described in the “De Octimestri Partu” the nuchal and chest coiling of the umbilical cord, and regarded it as “one of the dangers of the eighth month”. He also stated that when the nuchal cord persists until the term of pregnancy, it will cause suffering to the mother and either perish or born difficulties to the fetus. Other scholars from the Classics in Medicine consider that the “De Octimestri Partu” was not from Hippocrates but by an unknown disciple.

Gould also cited cases of multiple nuchal cord and described stillbirths probably related to severe cord compression1. In reviewing his text, some cases appeared to be simply amniotic band syndromes, but others appeared to be genuine cord strangulation.

Frequency

Nuchal cord is present in one-fourth of pregnancies but generally does not have major clinical significance. According to Larson, the occurrence of nuchal entanglement increases linearly from 5.8% at 20 weeks of gestation to 29% at 42weeks[4]. The presence of two or more loops is estimated to affect between 2.5% to 8.3% of all pregnancies.

Types

Giacomello classified the nuchal cord into two types[6]:

·        Type A - nuchal loop that encircles the neck in a freely sliding pattern (fig. 2)

·        Type B - nuchal loop that encircles the neck in a locked pattern (fig. 3)

Thus, type A can undo itself, while type B cannot.

Figure 3: Type B loop: a nuchal loop that encircles the neck in a locked manner. Should this fetus be delivered breech, the loop will get tighter around the neck of the fetus.

Ultrasound findings

The recognition of a single loop relies on the observation of a section of cord between the head and shoulder in a sagittal section, and the demonstration of a complete loop in an axial section of the neck. This is often difficult because of shadowing, and a compound image is often required. In an axial section, cord that is simply draped over the neck can be excluded. Color Doppler is the easiest mean to assess the cord in the axial view. Multiple loops are detected in the same manner, but the number of loops can only be counted in the sagittal section. Again, color Doppler is the easiest modality to count multiple loops. The assessment of the type (locking versus freely sliding) requires the demonstration of the crossing of one of the ends under the other end. This is easier in higher order looping since the cord is more taught, but if the crossing occurs behind the fetus, the diagnosis cannot be made.

Prognosis versus number of loops

Despite the good prognosis in most of the cases, some studies demonstrate that the presence of a nuchal cord is associated with variable fetal heart rate deceleration3^{, , [8],} , decreased fetal movement, umbilical arterial metabolic acidemia 7^,[11], neonatal anemia, and, in extreme situations, intrauterine fetal demise10. [12]

Multiple loops

In 1995, Larson, studying intrapartum complications associated with multiple nuchal cord entanglement, concluded that the group with four or more loops involved had significantly lower birth weight, more episodes of severe variable and late decelerations, meconium, and a higher incidence of operative delivery5.

Management

Multiple nuchal cord is probably the most common of  abnormal umbilical cord findings. Variable decelerations commonly occur during the first and second periods of labor. When episodes of cord compression are sufficiently spaced, the fetus can clear the increased CO_{­­­­­­­­­­­­­2} and maintain the oxygenation by using the oxygen reserve. However, if signs of fetal discomfort, such as decreased fetal movement or persistent fetal heart variable decelerations, or even signs of fetal distress like repeated late decelerations are present, operative intervention is recommended .

We speculate that, in the present case, the good Apgar scores and outcome at the nursery are attributed to the prompt intervention on the ultrasound findings.

Conclusion

Although the presence of a single nuchal cord does not require changes on the management of the pregnancy, the prenatal detection of multiple loops may alter the management and improve the outcome of these fetuses.

Our experience and the literature show that most cases of four or more nuchal loops are at high risk to develop complications in labor and delivery; thus, these cases demand caution and are more likely to end in an operative intervention.

References

[1] Gould, G.M., Pyle, W. L.(1896). Prenatal anomalies. Anomalies and curiosities of medicine. The Julian Press, Inc., New York, p95

[2] Hippocrates: De Octimestri Partu

[3] Pritchard J. A., Macdonald P. C., Gant N.F.(1985). Conduct of normal labor and delivery. Williams Obstetrics.17^th edition. Norwalk,CT, Appleton-Century Crofts , p340

[4]Larson, J.D., Rayburn, W.F., Harlan, V.L.(1997). Nuchal cord entanglement and gestational age. Am J Perinatol. 14(9): 555-557

[5] Larson, J.D., Rayburn, W.F., Crosby, S., Thurnau, G.R.(1995). Multiple nuchal entanglements and intrapartum complications. Am J Obstet Gynecol 173(4): 1228-1231

[6] Giacomello F: (1988) Ultrasound determination of nuchal cord breech presentation. Am J Obstet Gynecol 159:531-2

[7] Hankins, G.D.V., Snyder, R.R., Hauth ,J.C., Gilstrap III, L. C., Hammond, T.(1987). Nuchal cords and neonatal outcome. Obstet. Gynecol. 70(5): 687 - 691

[8] Anyaegbunam, A., Brustman, L., Divon, M., Langer, O.(1986). The significance of antepartum variable decelerations. Am J Obstet Gynecol 155: 707-710

[9] Tejani N.A., Mann, L.I., Sanghavi, M., Bhakthavathsalan A., Weiss, R.(1977). The association of umbilical cord complications and variable decelerations with acid-base findings. Obstet Gynecol 49: 159-162

[10] Steinfeld, J.D., Ludmir, J., Eife, S., Robbins, D., Samuels, P.(1992). Prenatal detection and management of quadruple nuchal cord. J Reprod Med 37(12): 989-991

[11] Stembera Z.K., Horska, S.(1972). The influence of coiling of the umbillical cord  around the neck of the fetus on its gas metabolism and acid-base balance. Biol Neonate 20: 214

[12] Collins, J.H.(1993). Two cases of multiple umbilical abnormalities resulting in stillbirth: prenatal observation with ultrasonography and fetal heart rates. Am J Obstet Gynecol 168(1): 125-128

[13] Feinstein, S.J., Lodeiro, J.G., Vintzileos, A.M., Weinhaum, P.J., Cambell, W.A., Nochimson, D.J.(1985). Intrapartum ultrasound diagnosis of nuchal cord as a decisive factor in management. Am J Obstet Gynecol 153(3): 308-309