Author
Information
Dwivedi JS*, Gupta AS**.
(* Third Year Resident **Professor, Department of Obstetrics & Gynecology, Seth G.S.Medical
College & KEM Hospital, Mumbai, India.)
Abstract
The
incidence of true knot of the umbilical cord which compromises the blood flow
is 0.04%-3% [1]. Umbilical cord with one loop around the neck is
found in about 20%-34% of cases but the incidence of two or three loops is 2.5%
to 5% and 0.2% to 0.5% respectively[2]. The following image shows a
rare incidence of two loops of umbilical cord around the neck with a true knot
being the probable cause of intra-uterine fetal demise.
This is the first case reported in world literature with a true knot in a twice
wound nuchal cord.
Introduction
There are
many maternal and fetal causes for intra uterine fetal demise. Presence of tight
loop of cord around the neck or presence of knot in the cord is one amongst
those multiple causes. When these two conditions are simultaneously present the
chances of fetal compromise increase tremendously. We hereby present a rare
case of intrauterine fetal demise due to two tight loops of cord around the
fetal neck with a co existing true knot.
Case
Report
A 34 years
old woman married since 8years G3P2L1IUFD1 with previous lower segment caesarean
section with 35 weeks of gestation came with a ultrasound (USG) scan suggestive
of intrauterine fetal demise. The cause of her previous
intrauterine fetal demise was undetermined. Her
serological and biochemical tests were within normal range. Pre-induction ripening of
the cervix with Foley’s catheter was done followed by oxytocin augmentation.
Patient delivered vaginally after 18 hours of induction. She delivered a female
fetus of
2.5kg with two tight loops of cord around the neck and also the presence of a
true knot in the nuchal umbilical cord as shown in figure
1.
Figure1:
Fresh still birth with the true knot (blue arrow) of umbilical cord and the two
loops of cord around the neck (green arrow).
Discussion
Umbilical
cord (Funis) is the connecting link between the fetus and placenta through
which fetal blood flows to and fro from the placenta. In general the
cord diameter is about 1.5cm and its length varies from 30-100 cm[3].
An average umbilical cord is 55cm long and approximately 1-2 cm in diameter. When this umbilical cord passes around the
neck 360 degrees it is called nuchal cord[4]. Umbilical cord has
nodes or swelling like structure at places. These swellings may be due to
accumulation of Wharton’s jelly (false knots) or may be due to actual twisting
of the cord upon itself (true knots). True knot is the type B pattern of nuchal
cord which is described as a hitch, which can’t be removed. True knots are most
likely to develop in early pregnancy when there is more liquor and are common
in cases of mono-amniotic twins, advanced maternal age, long umbilical cord and
fetal movements[5]. Due to the true knot, the blood flow to the fetus
is
compromised as the knot tightens due to either fetal movements or
during labor at the time of descent. Decreased venous return from the placenta
leads to asphyxia and sometimes intra uterine fetal demise. Perinatal
morbidity and mortality in the form of stillbirth is increased four to ten
times in case of true knot of umbilical cord[2].
Prenatal
detection of cord knot is very challenging and not always possible. However
detection of true knot antenatally by ultrasonography and four dimensional
color doppler and its vigilant management in the form of elective caesarean
section if required, can reduce the perinatal loss[6].
A medline, google, MD consult, Pubmed search did not yield any case reports
documenting a nuchal cord having a true knot. Case reports with true knots or
nuchal cords are well documented but this unfortunate dual tragedy is not yet
reported.
References
- Srinivasan A, Graves L, Mortimer B. Four true umbilical cord knots-JOGC http://www.jogc.com/abstracts/200601_Obstetrics_3.pdf
- Cunningham FG, Leveno KJ, Bloom SL, Spong CY , Dashe JS, HoffmanBL, et al, Placental abnormalities. Williams Obstetrics.24th ed, New York, Mc Graw Hill education books; 2014, pg123-124.
- Dutta DC, The placenta and fetal membranes. In Konnar HL, editor, Textbook of obstetrics including perinatology and contraception.7th ed, Delhi, New Central Agency(P) limited; 2011, pg40.
- Schaffer L, Zimmermann R. Nuchal cords. Available from http://www.uptodate.com/contents/nuchal-cords
- Beall MH, Ross MG. Umbilical cord complications. Available from http://emedicine.medscape.com/article/262470-overview#aw2aab6b6
- Ramon Y, Cajal CL, Martinez RO. Four dimensional ultrasonography of a true knot of the umbilical cord.Am J Obstet Gynecol.10/2006; 195:896-8.