European Journal of Cardiovascular Medicine

The umbilical cord has a function of connecting the placenta to the fetus and is formed by the 12^th week of the gestation and contains single vein and two arteries, all of which embeds to the Wharton’s jelly. The umbilical cord helps in the transportation of nutrients and blood from mother to fetus. The umbilical cord and its functions were first identified and reported in 384-322 BC by Aristotle. In the umbilical cord, blood flow is seen by the end of the 5^th week period of gestation.

The measurement of umbilical cord at term is nearly 50-60cm. It has a characteristic helical coiling pattern. The normal umbilical cord had only one coil for every 5cm o the length of the cord. The actual reason for the umbilical cord coiling is not clear, however, unequal vascular growth and fetal movement can result in the umbilical coiling.

The factors responsible for the helical pattern of the umbilical cord are not understood well, however, the evidence suggest that fetal activity can play a vital role in this phenomenon. Increase in the activity of the muscle in the fetus has been known to stimulate the growth of the umbilical cord. Also, umbilical coiling pose turgor to the umbilical unit which produce a strong and flexible cord. The pattern of coiling is considered to protect the umbilical cord from entanglement, stretching, pressure, and tension. 

Abnormal coiling of the umbilical cord can result in acute fetal effects as fetal demise and fetal labor intolerance and chronic fetal effects as growth retardation. The reason of abnormal umbilical cord coiling is unknown, it can be both Hypercoiled or Hypocoiled and both are linked to adverse perinatal outcomes as meconium staining, cesarean delivery for foetal distress, preterm delivery, and intrauterine death. The present study was aimed to evaluate the efficacy of umbilical coiling index as a potential marker for predicting neonatal morbidity.

The present prospective observational study was aimed to evaluate the efficacy of umbilical coiling index as a potential marker for predicting neonatal morbidity. The study was done at Department of Radiodiagnosis, of the Institute. Verbal and written informed consent were taken from guardians/parents of all the subjects before study participation.

The study assessed 282 subjects that were admitted to the Institute for delivery within the defined study period. The inclusion criteria for the study were subjects that were born as still birth, intrauterine fetal demise, and live birth, delivery by both LSCS (lower segment cesarean section) and vaginal delivery, singleton pregnancy, and pregnant females irrespective of their parity or gestational age. The exclusion criteria for the study were subjects that were drug abusers, smokers, single umbilical artery, anomalous fetus, or multifetal gestation.

After final inclusion of the study subjects, detailed history was recorded along with comprehensive general and routine obstetrical examination. Immediately following the delivery, cord clamping was done at 5cm distance from the fetal insertion avoiding the milking of the cord which might affect UCI. The placenta was spontaneously separated. The number of spirals or complete coils were counted from neonatal end towards placenta end of cord and depicted as per centimeter. Umbilical cord length was measured after placental delivery and 5cm was added to measured cord length. Dividing the total number of coils by the fetal length of cord in cm, umbilical coiling index was measured. The care was taken to not exert excessive traction on the cord while measuring.

Hypercoiled cords were defined as coils that had umbilical coiling indices less than the tenth percentile, Hypercoiled were coils that had umbilical coiling indices above the 90th percentile, and Normocoiled were coils that had umbilical coiling indices above the tenth but below the 90th percentile.

The various parameters assessed in the study subjects during the delivery were whether live baby was delivered or Intra uterine foetal demise, whether NICU admission required, birth weight, APGAR score at 1 minute and 5 minutes of life, and meconium staining of the liquor.

The present prospective observational study was aimed to evaluate the efficacy of umbilical coiling index as a potential marker for predicting neonatal morbidity. The study assessed 282 subjects that were admitted to the Institute for delivery within the defined study period. In all the study subjects, they were assessed for abnormal umbilical coiling using ultrasonography. Association of umbilical cord coiling to adverse fetal outcomes. For association of umbilical coiling index to meconium-stained liquor and IUGR in study subjects, IUGR was seen in 29.2% (n=14) subjects with hypercoiling, 58.3% (n=28) subjects with normal umbilical cord coiling, and 12.5% (n=6) subjects with hypocoiling of umbilical cord. For meconium-stained liquor, hypercoiling, normal coiling, and hypocoiling was seen in 7.1% (n=4), 67.9% (n=38), and 6.2% (n=14) study subjects respectively (Table 1).

Table 1: Association in umbilical coiling index to meconium-stained liquor and IUGR in study subjects

It was seen that for association of APGAR scores at 1 and 5 minutes to cord coiling in study subjects, for APGAR scores at 1 minute, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 23.8% (n=10), 61.9% (n=26), and 14.3% (n=6) study subjects respectively with APGAR score of ≤7. For APGAR scores at 1 minute, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 8.4% (n=20), 83.2% (n=198), and 8.4% (n=20) subjects with scores of ≥7. For APGAR scores at 5 minutes, concerning score of ≤7, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in no study subject and for score of ≥7, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 10.7% (n=30), 80% (n=224), and 10.7% (n=30) study subjects respectively (Table 2).

Table 2: Association of APGAR scores at 1 and 5 minutes to cord coiling in study subjects.

The study results showed that for association of cord coiling to baby weight in study subjects, for weight of <2.5kg, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in19.4% (n=14), 69.4% (n=50), and 11.1% (n=8) subjects. For weight of 2.5-3kg, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 9.3% (n=10), 81.5% (n=88), and 9.3% (n=10) subjects. For weight of >3 kg, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 5.9% (n=6), 84.3% (n=86), and 9.8% (n=10) subjects respectively (Table 3).

Table 3: Association of cord coiling to baby weight in study subjects

On assessing the association between umbilical cord coiling to IUFD and NICU admission. In subjects that needed NICU admission, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 16.7% (n=14), 71.4% (n=60), and 11.9% (n=10) study subjects respectively. In subjects that were born live, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 10.7% (n=30), 80% (n=224), and 9.3% (n=26) subjects and for subjects with IUFD, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in all 100% (n=2) subjects depicted the hypercoiling of the umbilical cord (Table 4).

Table 4: Association between umbilical cord coiling to IUFD and NICU admission

The present study assessed 282 subjects that were admitted to the Institute for delivery within the defined study period. In all the study subjects, they were assessed for abnormal umbilical coiling using ultrasonography. Association of umbilical cord coiling to adverse fetal outcomes. For association of umbilical coiling index to meconium-stained liquor and IUGR in study subjects, IUGR was seen in 29.2% (n=14) subjects with hypercoiling, 58.3% (n=28) subjects with normal umbilical cord coiling, and 12.5% (n=6) subjects with hypocoiling of umbilical cord. For meconium-stained liquor, hypercoiling, normal coiling, and hypocoiling was seen in 7.1% (n=4), 67.9% (n=38), and 6.2% (n=14) study subjects respectively. These results were consistent with the findings of Said AM et al⁵ in 2013 and Devaru D et al⁶ in 2012 where authors assessed subjects with umbilical cord coiling and its association to IUGR and meconium-stained liquor comparable to present study in their studies.

The study results showed that for association of APGAR scores at 1 and 5 minutes to cord coiling in study subjects, for APGAR scores at 1 minute, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 23.8% (n=10), 61.9% (n=26), and 14.3% (n=6) study subjects respectively with APGAR score of ≤7. For APGAR scores at 1 minute, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 8.4% (n=20), 83.2% (n=198), and 8.4% (n=20) subjects with scores of ≥7. For APGAR scores at 5 minutes, concerning score of ≤7, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in no study subject and for score of ≥7, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 10.7% (n=30), 80% (n=224), and 10.7% (n=30) study subjects respectively. These findings were in agreement with the results of de Laat M et al⁷ in 2005 and Kumar S et al⁸ in 2017 where for association of APGAR scores at 1 and 5 minutes to cord coiling reported by the authors was comparable to the present study.

It was seen that for association of cord coiling to baby weight in study subjects, for weight of <2.5kg, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in19.4% (n=14), 69.4% (n=50), and 11.1% (n=8) subjects. For weight of 2.5-3kg, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 9.3% (n=10), 81.5% (n=88), and 9.3% (n=10) subjects. For weight of >3 kg, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 5.9% (n=6), 84.3% (n=86), and 9.8% (n=10) subjects respectively. These results correlated with the findings of Machin GA et al⁹ in 2000 and Chholak D et al¹⁰ in 2017where association of cord coiling to baby weight comparable to the present study was also reported by the authors in their studies.

Concerning the assessment of the association between umbilical cord coiling to IUFD and NICU admission. In subjects that needed NICU admission, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 16.7% (n=14), 71.4% (n=60), and 11.9% (n=10) study subjects respectively. In subjects that were born live, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in 10.7% (n=30), 80% (n=224), and 9.3% (n=26) subjects and for subjects with IUFD, hypercoiling, normal coiling, and hypocoiling of the umbilical cord was seen in all 100% (n=2) subjects depicted the hypercoiling of the umbilical cord. These findings were in line with the findings of Patil NS et al¹¹ in 2013 and Rahi S et al¹² in 2017 where association between umbilical cord coiling to IUFD and NICU admission reported by the authors was comparable to the present study.

The present study concludes that abnormal coiling of the umbilical cord can be either Hypercoiled or Hypocoiled. It can lead to various adverse outcomes such as intrauterine fetal demise, meconium-stained liquor, and intrauterine growth restriction, however, the cause of abnormal umbilical coiling is unknown. Further prospective longitudinal studies with larger sample size must be done to assess that cause of abnormal umbilical cord coiling and efficacy of elective delivery to decrease the adverse perinatal outcomes.

1. Di Naro E, Ghezzi F, Raio L, Franchi M, D’Addario V. Umbilical cord morphology and pregnancy outcome. European Journal of Obstetrics & Gynecology and Reproductive Biology. 2001;96:150-7.
2. Cochard LR. Netter's atlas of human embryology: updated edition. Elsevier Health Sciences; 2012 Jun 18.
3. Gill RW, Kossoff G, Warren PS, Garrett WJ. Umbilical venous flow in normal and complicated pregnancy. Ultrasound in medicine & biology. 1984;10:349-63.
4. Spurway J, Logan P, Pak S. The development, structure and blood flow within the umbilical cord with particular reference to the venous system. Australasian journal of ultrasound in medicine. 2012;15:97-102.
5. Said AM, Mustafa SJ. Association of umbilical coiling index in normal and complicated pregnancies. Diyala Journal of Medicine. 2013;5:15-22.
6. Devaru D, Thusoo M. Umbilical coiling index & the perinatal outcome. The Journal of Obstetrics and Gynecology of India. 2012;62:43-6.
7. de Laat M, Franx A, van Alderen E, Nikkels P, Visser G. The umbilical coiling index, a review of the literature. The Journal of Maternal-Fetal & Neonatal Medicine. 2005;17:93-100.
8. Kumar S, Chetty S. Umbilical coiling index as a marker of perinatal outcome: An analytical study at Navodaya Medical College, Raichur. Indian Journal of Child Health. 2017;14:18-21.
9. Machin GA, Ackerman J, Gilbert-Barness E. Abnormal umbilical cord coiling is associated with adverse perinatal outcomes. Pediatric and Developmental Pathology. 2000;3:462-71.
10. Chholak D, Gupta P, Khajotia S. Study to evaluate association of umbilical coiling index and perinatal outcome. Int J Reprod Contracept Obstet Gynecol. 2017;6:408-12.
11. Patil NS, Kulkarni SR, Lohitashwa R. Umbilical cord coiling index and perinatal outcome. Journal of clinical and diagnostic research: JCDR. 2013;7:1675.
12. Rahi S, Akther G. Relationship of umbilical coiling index and perinatal outcome. Int J Reprod Contracept Obstet Gynecol. 2017;6:4433-6.