Velamentous insertion of the umbilical cord is an abnormal insertion of umbilical cord into the placenta. Normally the umbilical cord gets attached to the placenta in its central part. But in velamentous insertion the umbilical cord inserts itself in the membranes covering the fetus instead of the placental disc. These membranes are chorionic and amnionic membranes. Thus the umbilical vessels have to travel through the amnion and chorion before it reaches the placenta.
Since the blood vessels are not covered by the cord when in membranes, they are at risk of getting ruptured during the time of labor.It may cause severe bleeding in the pregnant woman and reduced oxygen supply to the fetus.
The exact etiology is not known, but certain risk factors include advance age during pregnancy, twin pregnancy, smoking, etc. Velamentous insertion of the umbilical cord does not require any specific treatment during pregnancy, but usually elective cesarean section is performed when the condition is known in advance with the help of sonogram. It reduces risk of complications.
Risk Factors For Velamentous Cord Insertion
The incidence of velamentous insertion of the umbilical cord is 1 in 100. This means out of every hundred pregnancies, one woman may be having velamentous insertion of the umbilical cord.There is no specific etiology found for this condition to develop. However, researchers believe the condition occurs due to abnormality in the placenta during its developmental stage.
Although the exact cause still remains obscure, there are several predisposing factors that increase the risk for its occurrence. They are as follows:
- Women who has undergone in vitro fertilization procedure.
- The age of pregnant woman is more than 35 years.
- History of velamentous insertion of the umbilical cord during earlier pregnancy.
- Woman carrying twins, especially if one is boy and other is girl.
- Smoking during pregnancy.
- History of previous cesarean section.
- Severe hypertension and proteinuria during second and third trimester.
- Diabetes during pregnancy also known as gestational diabetes.
Complications Of Velamentous Cord Insertion
Velamentous insertion of the umbilical cord does not pose any risk when the fetus is in the uterus. During this period both oxygen and nutrients from blood easily reaches the fetus properly. Risk and complication increases during the time of childbirth because there is significant chance of rupture of cord and bleeding from the umbilical vessels. It increases fetal mortality.
Sometimes velamentous insertion of the umbilical cord can compress the vessels and decrease blood flow. This can lead to growth retardation of the fetus. The risk of spontaneous abortion also increases, especially in second and third trimester. Rupture of blood vessels may occur if they are neat the cervix during the time of labor. It can lead to stillbirth.
Management Of Velamentous Cord Insertion
There is no treatment that can correct velamentous insertion of the umbilical cord. Thus once detected and confirmed with the help of sonogram, close and repeated monitoring of the woman during the whole course of pregnancy is needed. Patient is advised for regular ultrasound examination by her gynecologist.
In majority cases of known velamentous insertion of the umbilical cord elective cesarean section is preferred as it reduces the risk of complications. Woman with velamentous insertion of the umbilical cord must avoid certain activities such as climbing staircases, running and jogging, dancing, picking heavy objects during the last trimester. In majority of cases the prognosis of this condition is good if there is no associated complication.