At how many weeks is velamentous placenta dangerous?

Vela placenta is a relatively common symptom. The phenomenon of vela placenta is particularly harmful to the fetus. Pregnant women are advised to pay attention to regular prenatal checkups during pregnancy and observe the development of the fetus. Generally, it is better for pregnant women to do fetal heart monitoring once a week after 36 weeks of pregnancy. Many people do not understand at which weeks vela placenta will become dangerous. At which weeks vela placenta is dangerous? Let’s take a look at it next.

1. At how many weeks is velamentous placenta dangerous?

There is no set number of weeks after which a velamentous placenta becomes dangerous. However, if a velamentous placenta shows signs of labor, such as abdominal pain and uterine contractions, it is relatively dangerous and requires prompt hospitalization, pregnancy maintenance, or surgery.

Because the vascular branches around the velamentous placenta have lost the normal umbilical cord structure and lack the support of Wharton's jelly (embryonic connective tissue), vascular rupture is very likely to occur. Especially when these vascular branches are located below the fetal presenting part, crossing over or approaching the internal cervical os, it is medically called vasa previa. When blood vessels are compressed or the fetal membranes rupture, blood vessels tear, causing fetal hypoxia or acute blood loss. Since the blood volume of a full-term fetus is about 250 ml, if the blood loss exceeds 20% to 25% (i.e. 50 to 60 ml), fetal hemorrhagic shock may occur, and the fetal mortality rate is extremely high.

2. Typical symptoms of velamentous placenta

If the blood vessels on the fetal membrane cross the internal cervical os and are located in front of the fetal presenting part, it is called vasa previa. Vaginal delivery may aggravate the pressure on the vasa previa due to the dilation of the cervix and the descent of the presenting part, resulting in obstruction of umbilical cord blood circulation, fetal distress or death. If the vasa previa ruptures and bleeds, fetal distress may occur within a short period of time, leading to stillbirth or neonatal death.

3. Daily care

1. Evaluate the growth and development of the fetus every 4 to 6 weeks during pregnancy to detect fetal growth restriction and inconsistent fetal growth in a timely manner.

2. After 36 weeks of pregnancy, fetal heart monitoring should be performed at least once a week to determine whether there are changes in fetal heart rate due to vascular kink or compression.