Umbilical cord entanglement is a feature which can mean either one of more loops of cord being encircled around any part of the any part of body 3 or two umbilical cord getting entangled with each other. In the latter situation it is a classical feature of a monochorionic-monoamniotic twin pregnancy. Very rarely it can occur in with a diamniotic twinning with disrpution of the dividing membrane either naturally or secondary to a procedure such as amniocentesis.
It is often considered a part of normal early fetal development and can be a common finding in the 1st trimester. It has been described in over 70% of MCMA twin pregnancies and it is less of a problem in very early pregnancy.
If an associated tightening / knot is a concern Doppler assessment can be carried out.
If there is problamatic flow due to cord entanglement there may be evidence of abnormal RI's and S:D ratios, presence of diastolic notching and reduction in end diastolic flow in umbilical arterial Doppler assessment and pulsatile waveforms in umbilical venous flow assessment.
Cord entanglement itself is rarely a problem but an associated tightening leading to an umbilical cord knot is a concern where arterial compromise can cause catastrophic complications.
Considerations in ultrasound include
- 1. Larson JD, Rayburn WF, Crosby S et-al. Multiple nuchal cord entanglements and intrapartum complications. Am. J. Obstet. Gynecol. 1995;173 (4): 1228-31. Am. J. Obstet. Gynecol. (link) - Pubmed citation
- 2. Arabin B, Laurini RN, Van eyck J. Early prenatal diagnosis of cord entanglement in monoamniotic multiple pregnancies. Ultrasound Obstet Gynecol. 1999;13 (3): 181-6. doi:10.1046/j.1469-0705.1999.13030181.x - Pubmed citation
- 3. Dias T, Mahsud-dornan S, Bhide A et-al. Cord entanglement and perinatal outcome in monoamniotic twin pregnancies. Ultrasound Obstet Gynecol. 2010;35 (2): 201-4. doi:10.1002/uog.7501 - Pubmed citation
- 4. Rodeck CH, Whittle MJ. Fetal medicine, basic science and clinical practice. Elsevier Health Sciences. (2008) ISBN:0443104085. Read it at Google Books - Find it at Amazon
- 5. Baergen RN, Benirschke K(. Manual of Pathology of the Human Placenta. Springer Verlag. (2010) ISBN:1441974938. Read it at Google Books - Find it at Amazon
- 6. Tepper R, Kidron D, Aviram R et-al. High incidence of cord entanglement during early pregnancy detected by three-dimensional sonography. Am J Perinatol. 2009;26 (5): 379-82. doi:10.1055/s-0028-1110090 - Pubmed citation
- 7. Overton TG, Denbow ML, Duncan KR et-al. First-trimester cord entanglement in monoamniotic twins. Ultrasound Obstet Gynecol. 1999;13 (2): 140-2. doi:10.1046/j.1469-0705.1999.13020140.x - Pubmed citation