Placenta previa is when the placenta completely or partially covers the internal opening of the cervix, rather than the top or side of the uterus, and is most often detected in the second or third trimester during obstetric ultrasound examination, or when the A woman presents with symptoms of bright red vaginal bleeding, which usually does not cause pain.
At the beginning of pregnancy, it is normal for the placenta to be lower in the uterus, and as the pregnancy progresses and the uterus grows, the placenta moves to the upper or side of the inner wall of the uterus, away from the cervix, allowing your opening to be free for birth. When this does not happen, the placenta may remain obstructing the cervix.
The treatment of placenta previa is carried out by the obstetrician, who, in cases of little bleeding, may be advised to rest and avoid sexual intercourse. However, when placenta previa presents severe bleeding, hospitalization may be necessary to monitor and evaluate the baby and the pregnant woman. Furthermore, in more serious cases, an emergency cesarean section may be recommended.
Placenta previa symptoms
The main symptoms of placenta previa are:
- Vaginal bleeding, normally painless, bright red in color;
- Light or heavy bleeding that starts suddenly;
- Bleeding after intimate contact;
- Bleeding with contractions or sharp pain in the belly.
Symptoms of placenta previa are more common from the 20th week of pregnancy onwards, and breakthrough bleeding or spotting may also appear before the most intense bleeding.
Furthermore, placenta previa can increase a woman’s risk of developing placenta accreta, which is the attachment of the placenta to the myometrium, which is the middle layer of the uterus, which can lead to intense and massive bleeding. Understand better what placenta accreta is.
If symptoms of placenta previa are present, the pregnant woman should immediately go to the hospital to be examined by the obstetrician and the obstetrician will request an ultrasound to check the location of the placenta, as these symptoms are similar to placental abruption. Find out how placental abruption happens and what to do in these cases.
How to confirm the diagnosis
The diagnosis of placenta previa is made by the obstetrician through evaluation of symptoms, health history, gynecological examination and abdominal ultrasound examination. To confirm the diagnosis, the doctor must request a transvaginal ultrasound, which is safe to do and provides more accurate images of the placenta, making it possible to determine the type of placenta previa.
In pregnant women who do not present symptoms, placenta previa can be diagnosed by the obstetrician through routine prenatal ultrasound examination in the first or second trimester of pregnancy, with follow-up ultrasounds being necessary between weeks 28 and 32 of pregnancy to assess the condition. persistence of placenta previa.
Types of placenta previa
According to its location in the uterus, placenta previa can be classified into different types:
- Total placenta previa: the placenta completely covers the internal opening of the cervix;
- Partial placenta previa: the placenta partially covers the internal opening of the cervix;
- Marginal or lateral placenta previa: the placenta reaches the internal opening of the cervix, but does not cover it;
- Low implantation placenta previa: the placenta is located in the lower part of the uterus, but does not reach the internal opening of the cervix.
Although it does not always cause symptoms, placenta previa can cause vaginal bleeding, risk of premature birth or complications during childbirth. This problem is more common in women who are pregnant with twins, multiparous, who have previous uterine scars, who are over 35 years old or who have had previous placenta previa. Understand what the placenta is for and what problems you can develop during pregnancy.
Possible causes
The exact cause of placenta previa is not fully known, however, it appears to be related to injuries to the endometrium, which is the tissue that internally lines the uterus, or uterine scars.
Some factors can increase the risk of developing placenta previa, such as:
- History of placenta previa in previous pregnancy;
- Pregnancy after age 35;
- Having previously had a cesarean section;
- Scars on the uterus due to surgery;
- Having previously performed curettage;
- Twin pregnancy;
- Smoking;
- Use of drugs of abuse, such as cocaine.
Furthermore, having undergone assisted reproduction treatment for infertility can also increase the risk of developing placenta previa. See the main assisted reproduction treatments.
How the treatment is carried out
The treatment of placenta previa must be guided by the obstetrician and can be carried out in the hospital or at home, depending on the gestational age and the vaginal bleeding that the pregnant woman experiences. Generally, treatment involves rest and the adoption of some precautions, such as:
- Avoid making efforts and standing for a long time, remaining most of the day sitting or lying down, preferably with your legs elevated;
- Stop working, having to stay at home;
- Avoid having intimate contact.
Furthermore, selective cesarean delivery is recommended between the 36th and 37th weeks of pregnancy, when bleeding is controlled. However, an emergency cesarean section can be performed regardless of gestational age, when the baby and/or pregnant woman are at risk.
When the bleeding is intense, treatment involves hospitalization, with monitoring of the pregnant woman and the baby, and blood transfusions or an emergency cesarean section may be necessary.
In more serious cases, the doctor may also prescribe medicines to accelerate the development of the baby’s organs, as well as medicines to prevent premature birth and so that the pregnancy continues until at least 36 weeks of gestation. Check out the main consequences of premature birth.
Risks of placenta previa
The main risk of placenta previa for women is severe vaginal bleeding during pregnancy, childbirth or in the first few hours postpartum, which can put the woman’s life at risk.
In addition, placenta previa can also increase the risk of placenta accreta, which is when the placenta becomes attached to the wall of the uterus, making it difficult to exit at the time of birth, and causing hemorrhages requiring blood transfusion and, in the most serious cases, , total removal of the uterus, need for longer hospital stays, and risk of generalized infection, which can put the woman’s life at risk.
For the baby, the risks are premature birth, low birth weight, low APGAR scale, longer hospital stay in the neonatal care unit, and, in some cases, the need for a blood transfusion.
How is childbirth in case of placenta previa?
Cesarean section is indicated for any woman diagnosed with placenta previa, and is performed selectively in the 36th or 37th week of pregnancy, as the coverage of the cervix prevents the baby from passing, which can cause hemorrhage in the mother during a natural birth. .
However, normal birth is safe and can be performed when the placenta is located at least 2 cm away from the opening of the cervix, which will depend on the woman’s health conditions and the obstetrician’s assessment.
In addition, it may be necessary for the baby to be born prematurely, as the placenta may detach too early and harm the baby’s oxygen supply.
