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Previous placenta

It is known by the name of placenta previa the total or partial insertion of the placenta in the lower segment of the uterus, so that it can occlude the cervical os. Its frequency is approximately one in every 200 deliveries.

According to the relationship that exists between the lower border of the placenta and the internal orifice of the cervix (considering the cervix without dilatation, that is, before the start of labor), it is classified as:

  • Lateral placenta or low insertion: when the lower border of the placenta does not reach the uterine cervical os and is separated from it by less than 10 cm.
  • Marginal placenta: when the edge of the placenta contacts the internal orifice, but does not exceed it.
  • Occlusive placenta: when the placenta partially or totally occludes the internal cervical os. In the first case it is called a partial occlusive placenta, and in the second, a total occlusive placenta.

During childbirth, as a consequence of cervical dilation, the relationships between the placenta and the cervix can change, and can change from one variety to another.

Why is it produced?

The specific cause is not entirely known, but a series of factors that favor its appearance are known. Among these factors we find:

  • multiparity, which is one of the most important factors (appearing in 80% of multiparous women)
  • uterine scars (due to previous operations such as caesarean sections or myomectomies)
  • repeat abortions
  • uterine fibroids
  • uterine synechiae
  • the endometriosis
Lately it has been proven that there is a higher frequency of placenta previa in women who smoke.

Due to the factors that we have mentioned before, on the surface of the uterus there are altered areas that lead to the fact that, first, the placenta cannot implant in them, so it will be located in a lower area than normal and; second, these areas prevent adequate nutrition of the fetus, so the placenta will grow more than normal, being located closer to the cervical os.

Symptoms of placenta previa

The fundamental and most important symptom of placenta previa is vaginal bleeding, which usually appears in the 7th-8th month of pregnancy, in such a way that it is said that “all vaginal bleeding in the third trimester of pregnancy is a placenta previa until the contrary is proven.

This hemorrhage appears abruptly and unexpectedly, without being accompanied by any type of pain; it is liquid, red and not very abundant; It has a tendency to spontaneously subside, but it usually recurs by increasing the intensity of the bleeding and decreasing the time interval in which it appears.

How is it diagnosed?

As we have said before, a placenta previa should be suspected before any vaginal bleeding, during the third trimester of pregnancy. The existence of alterations in the fetal position (for example: transverse, oblique, breech situation) will also make us suspect this pathology.

If a placenta previa is suspected, a vaginal examination should never be done, since there is a risk of causing very intense bleeding or aggravating an existing bleeding, so the diagnosis will be confirmed by performing an ultrasound, which is the technique of choice for these cases.

You may also be interested in:   First symptoms of pregnancy

In the ultrasound, it is possible to observe the position of the placenta inside the uterus, determine if it is located in its lower segment, and the relationship it has with the cervical os.

Treatment of placenta previa

Treatment of the placenta previa is reduced to two possibilities:

  1. the abdominal route through a caesarean section, the objective of which is to inhibit bleeding by rapid uterine emptying.
  2. the vaginal route through artificial amniorrhexis, the objective of which is to try to inhibit bleeding due to descent of the fetal head, thus compressing the placenta against the wall of the uterus.

Behavior during pregnancy

The patient must be admitted to hospital at the first hemorrhage.

If the bleeding is massive and persistent, an urgent cesarean section is indicated.
In other cases, the measures will be the following:

  • Bed rest and administration of myometrial sedatives.
  • Assessment of blood loss and eventual replacement of losses, through transfusion.
  • Verification of vitality and fetal status.
  • Do not practice vaginal exams.
  • Location of the placenta by ultrasound.
  • Before the 34th week of pregnancy, watchful waiting should be observed, and only the administration of corticosteroids is indicated to accelerate fetal maturity. Cesarean section will only be indicated in case of severe and persistent bleeding.
  • From the 37th week of pregnancy, caesarean section is indicated for any bleeding, since the fetus is considered to have reached sufficient maturity to survive outside the uterus.
  • Between weeks 34 and 37, each case must be analyzed individually, assessing fetal maturity, the intensity of bleeding, the type of placenta previa, and the possible alteration of the fetal position.

Behavior during labor

A cesarean section is indicated in the following cases: occlusive placenta previa, intense bleeding at the beginning, patients with poor general condition, associated fetal position alterations; and when the woman is elderly and this is her first childbirth, or if she has undergone treatment for infertility. In all other cases, amniorrhexis will be carried out. If the bleeding is inhibited, labor should be allowed to evolve by its natural routes; in all other cases, the case must be resolved by cesarean section.

How can I avoid it?

Of all the factors that can influence the appearance of a placenta previa, the only one that can be avoided is smoking.

In other cases, you will have to take good control of the pregnancy with your gynecologist, especially if there are some of the factors that can lead to this pathology.

Every pregnant woman should go to her gynecologist before the appearance of any vaginal bleeding during pregnancy, so that it can be evaluated by the doctor.

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Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of ​​Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.

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