Introduction:
Histology:
3 umbilical vessels — 2 arteries and 1 vein in loose myxoid tissue (Whartons jelly). Ensheathed by amnion.
Pictures
False knot:
False umbilical knot, Macro, autopsy (73229)
Introduction:
Cord length is determined by mechanical stretching of the cord by fetal movements. The cord grows in 1st and 2nd trimestr in particular and approaches most of its ultimate length by 28 weeks.
Introduction:
Umbilical cord is shorter than 35 cm at term.
Etiology:
Congenital neuromuscular disorders, skeletal disorders, multiple malformations and similar conditions characterized by decreased fetal movements in utero.
Clinical signs:
Extremely short or absent umbilical cord is found in limb body wall complex. It is a severe malformation complex with large abdominal/thoracic wall defect, limb anomalies, severe scoliosis and internal anomalies. Limb body wall complex is uniformly lethal.
Clinical signs:
Velamentous (membranous) insertion: Occurs in 1% of singletons and in almost 15% of twins. The cord inserts into the membranes far away from the placental margin. Umbilical vessels run unprotected by Whartons jelly and are vulnerable to injury. Velamentous vessels run over the internal os are called vasa previa. These vessels are at risk of rupture during delivery. The mortality of vasa previa hemorrhage is very high, the fetus exsanguinates within minutes. Velamentous insertion can be detected before the delivery using color Doppler ultrasound. The fetus is delivered by elective cesarean section.
Marginal insertion: Insertion at the placental margin (battledore placenta) occurs in 5 – 7% pregnancies.
Pictures
Velamentous insertion of the umbilical cord:
Velamentous insertion, Macro, autopsy (73236)Velamentous insertion, Macro, autopsy (73237)
Vasa praevia rupta:
Vasa praevia, rupture, Macro, autopsy (74450)Vasa praevia, rupture, Macro, autopsy (74451)
Clinical signs:
Hypocoiled umbilical cord, achirality (absence of coiling) has adverse fetal outcome (intrauterine distress, intrauterine demise).
Hypercoiled cord, torsion Umbilical cord torsion (hypercoiling) is a freqent cause of abortion in the 2nd trimestr. Characteristic findings include long hypercoiled cord, stricture of the cord usually at the fetal end (focal depletion of Whartons jelly) or multiple strictures. The fetus is macerated.
Introduction:
SUA — single umbilical artery.
Clinical signs:
Classification:
Clinical signs:
The incidence of true knots is 0,5% – 1%. Nuchal cord with one loop is found in 20% of deliveries, two or three loops in 2.5% and 0.5% respectively. Cord prolapse is estimated to occur in 0.4% of deliveries.
Blood flow is compromised if the knot or nuchal cord tightens. The tightening occurs most often during delivery. Decreased venous return from the placenta leads to asphyxia. Cord compression may cause neurologic damage, intrauterine or intrapartum death. Perinatal mortality is approximately 10% in the presence of prolapsed cord or true knot.Strangulation by amniotic bands causes fetal demise.
Pictures
True knot:
True umbilical knot, Macro, autopsy (73230)True umbilical knot, Macro, autopsy (73231)
True umbilical knot, maceration:
True umbilical knot, maceration, Macro, autopsy (73712)
Etiology:
Clinical signs:
Venous thrombi are more common than arterial thrombi. Fetal outcome is poor.
Etiology:
Macroscopic appearance:
The umbilical cord looks normal. White, tan or yellow plaques are seen with Candida infection.
Histology:
Inflammatory cells migrate from the umbilical vessels towards the amniotic surface.
Introduction:
Subacute or chronic inflammation of the umbilical cord associated with high perinatal mortality.
Etiology:
Treponema pallidum, herpes simplex virus, other organisms with low virulence such as Mycoplasma are also suspected.
Macroscopic appearance:
Thickened whitish umbilical vessels resembling macaroni.
Histology:
Necrotizing basophilic exudate accumulates in concentric perivascular rings or crescents. The exudate may become calcified.
Classification: