Cord-Around-the Neck (Nuchal Cord) - Rivin

Strangulation of the Neck with the Umbilical Cord on Birth.

1. Cord-Around-the Neck (CAN ) ( Nuchal Cord ) W. P. Rivindu H. Wickramanayake Group no. 04a 4th Year 1st Semester – 2018 June Tbilisi State Medical University, Georgia

2. The umbilical cord is a narrow tube-like structure that connects the developing baby to the placenta. Occurs when the umbilical cord becomes wrapped around the fetal neck 360 degrees . Most of the nuchal cords diagnosed in early pregnancy get spontaneously uncoiled. Nuchal cord is present in one-fourth of pregnancies but generally does not have major clinical significance. Occurrence of nuchal entanglement increases linearly from 5.8% at 20 weeks of gestation to 29% at 42weeks . The presence of two or more loops is estimated to affect between 2.5% to 8.3% of all pregnancies .

3. History Hippocrates described in the “De Octimestr iPartu ” 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 .

4. Giacomello classification of the nuchal cord into two types: 1) Type A - nuchal loop that encircles the neck in a freely sliding pattern 2) Type B - nuchal loop that encircles the neck in a locked pattern Thus , type A can undo itself, while type B cannot. Types

5. Type A loop: a nuchal loop that encircles the neck in a freely sliding manner . Should this fetus be delivered breech, the loop can slide off the neck of the fetus . 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 .

6. Nuchal Cord Assessment A single loop - observation of a section of cord between the head and shoulder in a sagittal section, A complete loop - in an axial section of the neck. 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. C olor 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 . The assessment of the type ( locking versus freely sliding ) requires - 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.

7. 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 deceleration - decreased fetal movement - umbilical arterial metabolic academia - neonatal anemia - in extreme situations, intrauterine fetal demise

8. The cluster of cardiorespiratory and neurological signs and symptoms associated with unique physical features that occur secondary to tight cord-around-the-neck Nuchal cord and or tCAN can affect the outcome of delivery and may have long-term effects on the infant, but as a causative factor for stillbirth it is debatable. However , some case reports of postmortem findings on stillbirths show negative pathology reports and tight cord around the neck being the only cause of death  ' tCAN syndrome' (tight Cord Around the Neck Syndrome)

9. Umbilical cord compression due to tCAN may cause; - obstruction of blood flow first in thin walled umbilical vein, - while infant’s blood continues to be pumped out of baby through the thicker walled umbilical arteries - thus causing hypovolemia and hypotension resulting in acidosis. - Anemia and mild respiratory distress may occur. - Some may also have facial and conjuctival petechiae and - rarely petechiae of the neck and upper part of the chest and - skin abrasion of neck where the cord was tightly wrapped and - facial suffusion, all of wh ich can also be seen in some postmortem findings of stillbirth infants who had tCAN . If born alive, some of these infants may also be; - somewhat obtunded with a low tone and have transient feeding difficulties. These findings raise the possibility of transient encephalopathy, which may lead to long-term complications.

10. The tCAN Syndrome may conceptually be similar to strangulation which may result in non lethal problems or death. The pathophysiological mechanisms of strangulation injuries (lethal and non lethal) involves venous, arterial obstruction (arterial spasm due to carotid pressure) in the neck and vagal collapse (increased parasympathetic tone ). This can lead to cerebral stagnation, hypoxia, and unconsciousness , which, in turn, produces loss of muscle tone . A study on potentially asphyxiating conditions and spastic cerebral palsy in infants of normal birth weight showed evidence of association of tCAN in children with quadriplegia .

11. Intermittent umbilical cord occlusion in preterm and near term sheep caused a decline in pO 2  and pH, and higher PCO 2  and altered brain protein synthesis/degradation . Whether human fetal intermittent strangulation by tCAN have similar brain protein alterations and thus long-term effects remains to be seen. Using specific placental histologic criteria for umbilical blood flow restriction in unexplained stillbirth showed significant correlation of placental changes of “minimal histologic criteria” with cord accidents (as tCAN is part of cord accidents). Nuchal cords showed highest rates of thrombosis-related placental histopathology and fetal thrombotic vasculopathy and thrombosis seems to be highly specific for cord related stillbirths 

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, & a higher incidence of operative delivery . Management T he most common of  abnormal umbilical cord findings. Variable decelerations - during the first and second periods of labor. When episodes of cord compressions are sufficiently spaced, the fetus can clear the incre a sed CO ­­­­­­­­­­­­­2  and maintain the oxygenation by using the oxygen reserve . 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.

13. 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 . 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 . The good Apgar scores and outcome at the nursery are attributed to the prompt intervention on the ultrasound findings.

14. To show that such natural occurrence does not have significant effect on pregnancy, labor and neonates if proper intra-partum fetal heart rate (FHR) monitoring could be provided by a caregiver .   Materials and Methods:   For completing 100 cases with nuchal cord, they observed 506 cases and by which we took out the incidence of nuchal cord and which was separately categorized into single, double, triple and four and more than four groups.  Results: 1) Mean cord length also increases with number of loops (50.93 cm in single loop as compared to 72.33 cm) in cases with four loops. 2) Patients having tight nuchal cord have higher incidence of caesarean as well as forceps delivery. But these were not statistically significant ( P  = 0.56 and  P = 0.57) and Apgar score <7 at 1 min, FHR deceleration and meconi um staining of liquor were statistically higher significant ( P  = 0.001, P = 0.0001 and  P = 0.001, respectively).  Conclusion :   1) At present, expertise to diagnose multiple and tight loops on ultrasound are limited, which should be the aim for future. 2) Multi-centric & large studies are further required in association with more specific & sensitive diagnostic aid for tight & multiple loops so as to provide the best perinatal management with good fetal outcome. The study was conducted in the Department of Obstetrics and Gynecology at Sardar Patel Medical College, Bikaner (Rajasthan).

15. References : https ://www.ncbi.nlm.nih.gov/pmc/articles/PMC3428673/ https ://sonoworld.com/Client/TheFetus/page.aspx?id=172#_ednref4 https:// www.aihbonline.com/article.asp?issn=2321-8568;year=2017;volume=7;issue=1;spage=15;epage=18;aulast=Joshi

16. Rivin..® Thank You!