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 Table of Contents  
Year : 2020  |  Volume : 9  |  Issue : 16  |  Page : 94-96

True knotting of umbilical cord resulting in sudden unexpected fetal demise

1 Department of Obstetrics and Gynecology, JFK Liberian-Japanese Friendship Maternity Hospital, Monrovia, Liberia
2 Department of Obstetrics and Gynaecology, Bayero University Kano/Aminu Kano Teaching Hospital, Kano, Nigeria

Date of Submission08-Sep-2019
Date of Decision27-Jan-2020
Date of Acceptance21-May-2020
Date of Web Publication26-Nov-2020

Correspondence Address:
Dr. Ayyuba Rabiu
Department of Obstetrics and Gynaecology, Bayero University Kano/Aminu Kano Teaching Hospital, P.M.B. 3011, Kano
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/nnjcr.nnjcr_45_19

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Knotting of the umbilical cord is a significant cause of perinatal morbidity and mortality. It could be loose or tight. Tightening of the knot rarely occurs and when present can cause fetal demise. Antenatal features of the knotting of the umbilical cord are not only difficult to elicit but also usually do not conclusively establish the diagnosis. We report a case of true knotting of the umbilical cord in a 32-year-old female, who suddenly experienced decreased fetal movement and within 60 min had a fetal demise at 39 weeks of gestation. Intraoperative findings showed a stillborn female fetus, with no sign of maceration or congenital abnormality. The umbilical cord was relatively long and tightly knotted. To the best of our knowledge, this was the first case report of the true knotting of the umbilical cord in Liberia. Obstetricians and general practitioners should take caution that it remains an unseen cause of sudden intra-uterine fetal death during the antenatal period.

Keywords: Knotting of the umbilical cord, Liberia, sudden fetal demise

How to cite this article:
Saywon DM, Rabiu A. True knotting of umbilical cord resulting in sudden unexpected fetal demise. N Niger J Clin Res 2020;9:94-6

How to cite this URL:
Saywon DM, Rabiu A. True knotting of umbilical cord resulting in sudden unexpected fetal demise. N Niger J Clin Res [serial online] 2020 [cited 2021 Apr 22];9:94-6. Available from: https://www.mdcan-uath.org/text.asp?2020/9/16/94/301645

  Introduction Top

True knotting of the umbilical cord is defined as the looping or interweaving of the umbilical cord during the intra-uterine growth of the fetus.[1] It is usually seen incidentally at delivery whether vaginal or cesarean section and is usually seen loosely knotted. It is very rare and regarded as a highly unprecedented complication of pregnancy that can lead to fetal demise or neonatal death.[2] The incidence of a true knot is very low. A figure of 1.2% was reported in India.[3] On the other hand, false knots are relatively common and are developmental variations with no clinical significance.[4] Predisposing factors to true knot formation during intra-uterine life include male fetus, gestational diabetes, long umbilical cord, polyhydramnios small fetus, and multiparty.[2] Maternal anemia, previous miscarriage, and obesity were also reported as risk factors for true umbilical cord knotting.[5]

  Case Report Top

The patient was a 32-year-old booked G8P2+5, 2 alive at 39 weeks of gestation who presented to the Liberian–Japanese Friendship Maternity Center of the John F. Kennedy Memorial Hospital with a complaint of reduced fetal movement. Index pregnancy was spontaneously conceived. She booked at ELWA Hospital. She had seven antenatal visits, which were uncomplicated. She received two doses of sulfadoxine–pyrimethamine for intermittent preventive therapy of malaria and two doses of tetanus toxoid injection. Ultrasound done at the referring hospital revealed normal findings. She was also screened for gestational diabetes. She had two previous cesarean sections on account of fetal macrosomia and preeclampsia with severe features. She was first seen at ELWA hospital with the same complaint. Following examination, she was told about the fetal heart rate of 100 beats/min. She was immediately referred to the Liberian–Japanese Friendship Maternity Center of the John F. Kennedy Memorial Hospital within 1 h. On examination, she was found to be a young woman, anxious. She was not pale, afebrile. Her vital signs were normal. The abdomen was uniformly enlarged. Symphysis-fundal height was 39 cm, longitudinal lie, and cephalic presentation. Fetal heart tone was absent by fetal Doppler; abdominal ultrasound showed nonviable intra-uterine gestation. Placenta was antero-fundal and amniotic fluid index of 8 cm.

On pelvic examination, the cervix was closed, uneffaced, posterior, and head stationed at − 3. Other findings were unremarkable. Relevant laboratory investigations such as urinalysis and random blood sugar were unremarkable. Her blood type was O Rhesus D positive, malaria smear negative; retroviral screening venereal disease research laboratory and hepatitis B surface antigen were all negative. Her hemoglobin was 12.5 g/dl.

The diagnosis of multipara with two previous cesarean sections and intra-uterine fetal death at 39 weeks of gestation was made.

She was counseled on her condition. Consent for cesarean delivery was obtained. Intra-operative findings were moderate pelvic adhesions, thinned-out lower uterine segment, and fresh still birth female neonate weighing 3.9 kg. The amniotic fluid was clear. The umbilical cord was seen abnormally long about 72 cm (normal length 50–60 cm), centrally attached to the placenta, and a tightened true knot was seen about 22 cm away from the umbilicus [Figure 1]. A postoperative diagnosis of intra-uterine fetal death secondary to true knotting of the umbilical cord was made.
Figure 1: True knot of the umbilical cord

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  Discussion Top

Obstetricians are often confused and uncertain about the exact timing of true knotting. Antenatal diagnosis has not been reported in literature nor has been a documented case report in Liberia. This may be attributed to the reluctance for clinicians to check during the antenatal period, lack of sonographic skills, or lack of ultrasound in many of our health facilities in Liberia. There is no robust literature on the diagnosis of the true knot of the umbilical cord prenatally, and it is regularly an incidental discovery. Its prenatal qualities may not be obvious.[6]

Demonstration of “cloverleaf pattern” on gray-scale images of obstetric ultrasound has been described as an ultrasound feature of the true knot of the umbilical cord;[7],[8] however, in our poor-resource setting, where the skilled sonographers are lacking, such ultrasound feature is difficult to be elicited. In one study by Sepulveda et al.,[7] they concluded that routine abdominal ultrasound for visualization of the abdominal insertion, cord-free and floating-free segments of the umbilical cord during the evaluation of the amniotic fluid volume are insufficient for making the diagnosis of true umbilical cord knot at antenatal assessment. Routine fetal umbilical Doppler examination on all pregnant mothers during the third trimester or at term may enable the identification of abnormal patterns in pregnancies complicated by true knot.[9] However, routine Doppler velocimetry in all pregnant women during the antenatal clinic is not cost effective in our setting.

Thus, this is true for our patient who underwent routine antenatal care, had at most two sonogram examinations, and true knot could not easily be detected, and the diagnosis was missed. A 4-fold increase in fetal loss has been reported to result from a true knot due to the tightening of the knot and subsequent compression of vessels.[10] This apparently explains the sudden fetal demise in this case.

Multiparty and slightly long umbilical are the only identifiable predisposing factors, in this case; otherwise, the fetus was a female, normal amniotic fluid volume, and fetus above-average weighed 3.9 kg. Diabetes mellitus was ruled out during the antenatal period and a relatively young maternal age of 32 years. We could not establish whether the five abortions were spontaneous or induced.

Considering the pathophysiology of the true knot of the umbilical cord, it develops early in pregnancy when intrauterine space is available for excessive fetal movement. As the fetus enlarges, a true knot may tighten, or tightening may occur at delivery when the umbilical cord undergoes traction. Constriction or hematoma development may lead to fetal hypoxia, neurologic impairment, or fetal demise. Clinically significant circulatory compromise may often be associated with edema, congestion, constriction, hemorrhage, or thrombosis.[11] Most of these findings were observed in this case, as the knotted cord was seen to be tightened, edematous, constricted, and congested.

Concerning management, vaginal delivery is not usually encouraged. The diagnosis of knots at term or at labor onset may require a trial of labor since the majority of knots seem to be protected against occlusion by the greater thickness of Wharton's jelly and the large cord radius at this gestational age.[6] However, at the time of fetal descent through the birth canal, the knot could be tightened, thus occluding fetal circulation and resulting in the demise of the fetus. In this patient, the case was missed at the antenatal visit. We would have apparently counseled the patient for early-term cesarean at 37 completed weeks other than waiting for 39 weeks, but we lack the capacity for diagnosis, close and rigorous fetal monitoring. The decision to deliver her by cesarean section was because she had two previous cesarean sections, and it was not changed despite the fetal demise simply because of poor Bishop's scores and the fear of uterine rupture following the induction of labor with uterotonics.

  Conclusion Top

The diagnosis of true umbilical cord knots during the antenatal period remains a serious challenge, as there is no robust presentation for making the diagnosis. It is important to inform pregnant women attending for antenatal care should be conscious of the fact that even in the midst of being strictly adherent to antenatal follow-up and being aware of the danger signs of pregnancy for which prompt hospital visit is needed, there could still be sudden and prenatally unexplained death of the fetus that the cause could only be made in the postpartum period.

We recommend that the scientific community needs to do more in finding a more precise way for the prenatal diagnosis of true knotting of the umbilical cord.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Sørnes T. Umbilical cord knots. Acta Obstet Gynecol Scand 2000;79:157-9.  Back to cited text no. 1
Spellacy WN, Gravem H, Fisch RO. The umbilical cord complications of true knots, nuchal coils, and cords around the body. Report from the collaborative study of cerebral palsy. Am J Obstet Gynecol 1966;94:1136-42.  Back to cited text no. 2
Soliriya V, Goyal M, Kachhawaha C. Perinatal mortality and umbilical cord parameters: Is there any association? J Preg Child Health 2017;4:340. Available from: https://www.omicsonline.org/open-access/perinatal-mortality-and-umbilical-cord-parameters-is-there-any-association-2376-127X-1000340.php?aid=91570. [Last accessed on 2020 Jun 20].  Back to cited text no. 3
Maher JT, Conti JA. A comparison of umbilical cord blood gas values between newborns with and without true knots. Obstet Gynecol 1996;88:863-6.  Back to cited text no. 4
Airas U, Heinonen S. Clinical significance of true umbilical knots: A population-based analysis. Am J Perinatol 2002;19:127-32.  Back to cited text no. 5
Ikechebelu J, Eleje G, Ofojebe C. True umbilical cord knot leading to fetal demise. Ann Med Health Sci Res 2014;4:S155-8.  Back to cited text no. 6
Sepulveda W, Shennan AH, Bower S, Nicolaidis P, Fisk NM. True knot of the umbilical cord: A difficult prenatal ultrasonographic diagnosis. Ultrasound Obstet Gynecol 1995;5:106-8.  Back to cited text no. 7
Ramón y Cajal CL, Martínez RO. Four-dimensional ultrasonography of a true knot of the umbilical cord. Am J Obstet Gynecol 2006;195:896-8.  Back to cited text no. 8
Krzyżanowski A, Kwiatek M, Gęca T, Stupak A, Kwaśniewska A. Modern ultrasonography of the umbilical cord: Prenatal diagnosis of umbilical cord abnormalities and assessment of fetal wellbeing. Med Sci Monit 2019;25:3170-80.  Back to cited text no. 9
Hershkovitz R, Silberstein T, Sheiner E, Shoham-Vardi I, Holcberg G, Katz M, et al. Risk factors associated with true knots of the umbilical cord. Eur J Obstet Gynecol Reprod Biol 2001;98:36-9.  Back to cited text no. 10
Kowalski PJ. Placenta Umbilical Cord Knots. Available from: https://www.pathologyoutlines.com/topic/placentaknots.html. [Last accessed on 2019 Sep 08].  Back to cited text no. 11


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