Symptoms, signs and complications
For further information: Placenta Previa Symptoms
The only characteristic symptom of placenta previa is vaginal bleeding (haemorrhage), which begins in the second half of pregnancy.
In fact, other symptoms and signs may also occur, but these, unlike vaginal bleeding, occur in a small minority of cases and are episodic.
Therefore, the following can be added to the bleeding:
- Ache
- Uterine contractions
- Fetus in transverse or oblique position
THE BLOODING
The bleeding from the vagina is deep red and painless. It begins in the second half of pregnancy, usually after the 28th week. The onset is sudden and, in some cases, intermittent, or it stops for a few days before resuming. The quantities of blood lost are variable, sometimes large and sometimes modest.
Hemorrhage can be considered the only sign of placenta previa, as it is the only one ever present in patients.
OTHER SYMPTOMS
Pain occurs when placenta abruption is associated with placenta previa. This combination occurs in about 10% of cases. Pain is a characteristic sign of placental abruption.
Uterine contractions occur in about 25% of cases. They resemble those of labor and last for a few days.
The badly positioned fetus, transverse or oblique, is typical of a good 15% of cases.
THE FETUS
As long as the conditions are stable, the fetus does not present any particular disorders. In fact, fetal distress appears at the onset of complications.
What is fetal distress?
Fetal distress is a vague term that identifies a number of different disorders, including heart abnormalities, impaired intrauterine growth, and oligohydramnios.
COMPLICATIONS
Women with placenta previa need to be followed closely, as there is a possibility that the blood loss will increase to the point of being life threatening.
But on what occasions can this worsening occur?
An enormous increase in bleeding can occur during labor, at the time of delivery or a few hours after delivery. In these situations, the medical staff must be prepared, since the pregnant woman is at high risk of hemorrhagic shock (or hypovolemic shock) and requires immediate blood transfusion.
Furthermore, conspicuous blood loss can occur even when the pregnancy is not at full term. The consequences, in these cases, also affect the health of the fetus, not just the mother. In fact, the so-called condition of fetal distress can arise and the need to deliver the baby prematurely, by Caesarean section.
WHEN TO SEE THE DOCTOR?
A pregnant woman, who is prone to blood loss in the second half of pregnancy, is advised to contact her gynecologist. If the bleeding is significant, do not delay in doing so, as it is an emergency.
Diagnosis
The diagnosis of placenta previa is based, first of all, on a gynecological clinical examination and, secondly, on instrumental examinations (ultrasound and nuclear magnetic resonance).
GYNECOLOGICAL CLINICAL EXAMINATION
The doctor investigates the origins of the bleeding:
- What week did it happen?
- What color is the blood?
- Is it conspicuous? Is it intermittent?
These are the cornerstones of the investigation.
Abdominal examinations are also performed to check the consistency of the uterus, and vaginal examinations are avoided, since they could worsen the bleeding.
Finally, it is possible that the specialist performs the so-called Leopold's maneuver, to understand the orientation assumed by the fetus in the womb. As will be recalled, a small percentage of cases of placenta previa present with a fetus in a transverse or oblique position.
ULTRASOUND
Ultrasound is the diagnostic test of choice to confirm suspicions of placenta previa. However, for some pregnant women, the revelation is random, following a normal routine check-up.
Even clearer information is obtained if, to the classic abdominal ultrasound, transvaginal ultrasound is added, in which a very small probe inserted into the vagina is used. In these situations, the specialist pays the utmost attention not to cause blood loss from the vagina.
The test is reliable if it is carried out between the second and third trimesters of pregnancy (see the discussion on false positives).
False positives
There are situations where, based on ultrasound results, a case of placenta previa is mistaken.
For example, early ultrasound checks (those performed in the first half of pregnancy) may show that the placenta is positioned at the cervix. In reality, these are not reliable and definitive images, as, from the second trimester onwards, the fetus and uterus grow and the placenta moves accordingly.
Another circumstance, much less common than the previous one, is linked to the bladder and the possibility that this, if filled with urine, compresses the uterus, changing (only apparently) its anatomy. The placenta, therefore, appears to be misplaced, but, in fact, it is not.
NUCLEAR MAGNETIC RESONANCE
It occurs rarely and also helps to understand the exact position of the placenta.
Therapy
When we talk about therapy for placenta previa, we refer to those countermeasures that aim, in less serious cases, to carry the pregnancy to term without complications and, in the most serious cases, to save the life of the mother and fetus.
In light of this, the therapeutic path must consider the following factors:
- The location of the placenta in the cervix
- The severity of the bleeding and its modalities (for example, if it is intermittent or continuous)
- Week of pregnancy
- Mother's health
- Health of the fetus
Based on these fundamental points, we act accordingly.
THE POSITION OF THE PLACENTA
If the placenta previa is classified as Grade I or Grade II, vaginal delivery is performed.
This is the course of action, in general, in such situations. However, each patient represents a separate case and should be treated accordingly. For example, a non-serious condition of placenta previa may present with "intense blood loss, requiring a cesarean delivery.
If, on the other hand, the placenta previa is grade III or grade IV, a caesarean section is always opted for. In this regard, the following rule applies: if the placenta is located less than 2 cm away from the opening of the cervix, a caesarean section is performed.
WHEN BLOOD LOSS IS MINIMAL OR ABSENT
If the bleeding is low or absent, the patient does not need hospital care or even hospitalization. The only recommendation, which is made, is to rest and avoid sexual intercourse and most physical activities. If things remain this way, the pregnancy is expected to end: vaginal delivery, for grades I and II; Caesarean section, for grades III and IV.
WHEN BLOOD LOSS IS CONSISTENT
In the face of consistent blood loss, urgent action must be taken and the possibility of a premature birth as well as a hysterectomy (removal of the uterus) must also be considered.
They are fundamental:
- The hospitalization, to monitor the patient
- A blood transfusion, even a large one, if the bleeding is significant
If we do not act in a timely manner, the situation, as we have seen, can become further complicated: shocks appear, to the detriment of the pregnant woman, and fetal distress, to the detriment of the baby.
Premature birth by caesarean type
Condition
How do you act?
Prognosis and prevention
The prognosis for a woman with placenta previa differs according to the case considered and depends on at least two factors.
- The first factor concerns the degree of severity with which the disorder presents itself. Grade I or II placenta previa has less negative impact on the health of mother and baby than grade III and IV placenta previa. What makes the difference are the methods of delivery: risks and consequences (for example, hysterectomy), related to a caesarean section, are more than those of a vaginal birth.
- The second factor concerns the quality of the care received by the mother. If the diagnosis is early and the treatment timely and suitable (immediate transfusion, correct birth, etc.), the prognosis tends to be positive, at least for the pregnant woman.
IS IT POSSIBLE TO HAVE OTHER PREGNANCIES?
As long as she has not had a hysterectomy, a woman who has had placenta previa can have other pregnancies. However, it is highly recommended that you contact your gynecologist, who will assess the situation and tell you how to behave
THE PROGNOSIS FOR A PREMATURE FETUS
It has been observed that the baby, born to a woman with placenta previa, is more prone to develop:
- Sudden Infant Death Syndrome
- Growth delays
- Malformations
- Delays in neurodevelopment
N.B: we are talking about a higher than normal risk, not a certain and natural consequence.
PREVENTION
Although there is no specific preventive measure, limiting risk factors (for example, not smoking and not using cocaine) is the best behavior to reduce the chances of developing placenta previa.
