Placenta previa: covering, accreta… What are the risks for pregnancy?

THE placenta previa is part of pregnancy complications. Typically, the placenta is located on the upper uterine wall of the uterus. But in the case of placenta previa, it is placed in the lower part of the uteruswhat can lead to symptoms and risks for pregnancy. What causes placenta previa? What are the symptoms ? Can we give birth safely? Answers with Dr. Cécile Pénager, gynecologist-obstetrician.

What is placenta previa?

“We speak of placenta previa when the placenta is inserted too low in the uterus, that is to say less than 5 cm from the cervix., explains Dr Pénager. In this illustration, the placenta is shown in dark red.

Placenta previa concerns about 1 in 800 deliveriesindicates Antonette T. Dulay, gynecologist-obstetrician, in her article published in the review MSD Manuals.

What is overlying placenta previa?

The phrase “placenta previa covering” is also used, because placenta previa covers the opening of the cervix, the entrance to the vaginal canal. As a result, if the woman has already delivered by caesarean section, it may also increase the risk of a placenta accreta.

What does placenta previa accreta mean?

This is a placenta that is “abnormally attached to the uterus”a other serious pathology of pregnancyindicates another specialist, Julie S. Moldenhauer, gynecologist-obstetrician in her article published in the review MSD Manuals.

What can cause placenta previa?

There are several risk factors that can lead to placenta previa:

• In vitro fertilization
• A uterine malformation (fibroma)
• A history of low placed placenta
• A history of multiple pregnancies
• A history of cesarean delivery
• Smoking
• Advanced age

What are the risks of placenta previa?

Placenta previa may present with risks for pregnancy and the health of the future baby. “The placenta being very close to the cervix, there are more risk of small detachments and bleedingfrom the second trimester of pregnancy, explains Dr Pénager. If the bleeding is light, it may only require short-term hospitalization.

On the other hand“if the bleeding is accompanied by uterine contractionswe are faced with a real table of threat of premature delivery. The pregnant woman is then hospitalized to monitor the bleeding, make sure the baby is fine and stop the contractions., adds the specialist. The mother-to-be remains hospitalized until the bleeding stops and then goes out with sick leave.

“There are risks of small detachments and bleeding, uterine contractions. In severe cases, threat of premature labor and severe bleeding.”

What are the symptoms of placenta previa?

Several symptoms accompany placenta previa, whether for the pregnant woman or the fetus. The mother-to-be may have bright red vaginal bleeding, normally painless. As for the fetus, it can adopt a abnormal position in his mother’s womb, to have intrauterine growth retardationor it may cause a premature rupture of membranes.

If the mother-to-be has no symptoms, placenta previa is usually detected. during second trimester ultrasound.

Can the placenta come up during pregnancy?

“It happens that the low inserted placenta goes up and inserts normally at the end of pregnancy, especially because the uterus lengthens“, specifies our speaker. On the other hand, it is much rarer in the case of a covering placenta, which generally does not go up enough to discover the cervix.

What are the recommendations on placenta previa during pregnancy?

“If the diagnosis is made without any symptoms, the woman is told to live her life normally and to consult if she has any bleeding,” explains the gynecologist. However, the latter insists on the need to be careful during sex which, if not prohibited, must be mild.

It is also important that the mother-to-be communicates about placenta previa to the professionals who may have to examine it so that they are very careful during examinations (vaginal examination is prohibited). The doctor will then use endovaginal ultrasound to measure the cervix.

CNGOF recommendations:

The CNGOF (National College of French Gynecologists and Obstetricians) recommends that pregnant women with placenta previa:

• strict rest
• Close monitoring
• “Before 34 WA, prenatal corticosteroid therapy for prevention”
• “Before 33 WA, administration of magnesium sulphate in order to reduce the risk of cerebral palsy in the event of prematurity”
• A tocolytic treatment for contractions
• “A search for a factor triggering uterine contractions”
• “A Kleihauer test on speculum-collected blood to assess fetal involvement in hemorrhage”

What are the consequences of placenta previa for childbirth?

The decision to give birth will depend on the position of the placenta at the end of pregnancy. “If the placenta is low inserted, but more than 1.5 cm from the cervix (to be reassessed on the day of labor), vaginal delivery can be authorized. But there is a greater risk of bleeding and postpartum hemorrhage after childbirth. However, this requires more careful monitoring.“, explains Dr. Pénager.

If the placenta is really low, cesarean section is inevitable. “We do an ultrasound to locate the placenta at 37 SA. If it is really covering, we program the cesarean from 38 weeks to avoid spontaneous labor“, she details.

Thanks to Dr Cécile Pénager, gynecologist-obstetrician.