Placenta Praevia: Why Does It Happen During Pregnancy?

Pregnancy is full of surprises, and sometimes, it throws a curveball. One such curveball is placenta praevia. It's when the placenta, the organ that nourishes the baby, attaches to the lower part of the uterus instead of the upper part. While this may sound complex, it's a fairly common condition that can be managed with careful monitoring and doctor-guided treatment.

Studies have reported that the incidence of placenta praevia in India ranges from 0.3% to 2%. A history of previous uterine procedures can increase the risk of placenta praevia due to the presence of scar tissue on the uterine lining, which can interfere with the normal implantation of the placenta.

We need more research to get a better picture. Large studies that examine many women across India can help us better understand the link between age and placenta praevia. 

What exactly is placenta praevia?

Placenta praevia is a pregnancy issue in which the placenta, which feeds the foetus, partially or completely covers the cervix. The cervix is the bottom portion of the uterus that leads into the vagina. This condition inhibits a safe vaginal delivery. 

The placenta usually attaches to the upper part of the uterus. Placenta praevia happens when the placenta is located in the lower part of the uterus or covers the cervix. If it grows into the uterus's muscle, it can become very firmly attached, resulting in placenta accreta.

What are the types of placenta praevia?

It's worth noting that placenta praevia might change throughout the pregnancy. As the uterus expands, a marginal placenta praevia might become partial or entire. The condition is classified into three kinds, each with a different degree of severity and associated consequences.

1. Total placenta praevia: This is the most risky form, in which the placenta covers the cervix and blocks the baby's birth canal. This position greatly raises the risk of serious bleeding during the antenatal period, particularly during labour and delivery.

2. Partial placenta praevia: The placenta partially covers the cervix, blocking a piece of the delivery canal. While not as severe as total placenta praevia, it can nevertheless cause substantial bleeding, especially during labour and delivery.

3. Marginal placenta praevia: In this least severe kind, the placenta's edge reaches but does not completely cover the cervix. While normally less dangerous, it can still result in bleeding, particularly during the third trimester.

What is the difference between placenta praevia and placental abruption?

Placenta praevia and placental abruption are two distinct pregnancy complications that can cause vaginal bleeding, but they differ significantly in their underlying causes and mechanisms. Here’s the difference between placenta praevia and placental abruption. 

Symptoms of placenta praevia you should watch out for

The most common sign of placenta praevia is painless vaginal bleeding. This bleeding can vary from little spotting to heavy bleeding and can occur at any time during the second or third trimester of pregnancy. While vaginal bleeding is the most prevalent sign, some women with placenta praevia may not exhibit any symptoms at all. The problem may be detected only during a routine ultrasound.

In some cases, women with placenta praevia may also experience:

• Pelvic pressure: A feeling of heaviness or fullness in the pelvis

• Backache: A dull, persistent ache, particularly in the lower back

It's crucial to remember that any amount of vaginal bleeding during pregnancy should be reported to your healthcare provider immediately.

What can cause placenta praevia?

While the exact cause of placenta praevia is often unknown, several factors can increase the risk:

1) Uterine scarring: Previous uterine procedures can scar the uterine lining, making it more likely for the placenta to attach abnormally.

2) Uterine anomalies: Abnormalities in the shape or structure of the uterus can contribute to placenta praevia.

3) Previous placenta praevia: Women who have had placenta praevia in a previous pregnancy are at higher risk of experiencing it again.

4) Multiple gestations: Carrying twins, triplets, or more multiples can increase the risk.

5) Advanced maternal age: Women of advanced maternal age are at slightly higher risk.

Many of the above factors may increase the risk of developing placenta praevia. However, it's important to note that many women with these risk factors will not develop the condition.

What are the possible complications?

Placenta praevia, if not managed carefully, can lead to complications. Premature birth is a common concern, as the low-lying placenta can make the uterus more sensitive to contractions, leading to early labour. Antepartum and postpartum haemorrhage are another potential risk, especially if the placenta doesn't fully separate from the uterine wall after delivery. In severe cases, an emergency surgery may be necessary to address heavy bleeding or foetal distress.

However, with regular prenatal check-ups and careful monitoring, most moms with placenta praevia have healthy pregnancies and deliveries. The key is early detection and appropriate management to minimise risks.

Can you have placenta praevia without bleeding? 

Yes, it's possible to have placenta praevia without experiencing vaginal bleeding. Although bleeding is a common sign, it does not always occur. In certain circumstances, the problem may only be identified during a routine ultrasound.

That is why regular prenatal check-ups, especially ultrasounds, are critical for the early discovery and treatment of placenta praevia. Even if you don't have any symptoms, these routine checkups can help diagnose the disease and guarantee a healthy pregnancy and birth.

Why does placenta praevia cause bleeding?

The reasons for bleeding in placenta praevia could be the following:

• Cervical os exposure: When the placenta covers the cervix, any activity that stretches or irritates it, like intercourse or a vaginal exam, can cause bleeding by disrupting the placenta's fragile blood veins.

• Placental separation: In some situations, the placenta may separate from the uterine wall, particularly during labour. This separation might result in bleeding because the blood arteries that nourish the placenta are disturbed.

How is placenta praevia diagnosed and treated?

Placenta praevia is diagnosed through an ultrasound, either during a routine scan or if a woman experiences symptoms like painless vaginal bleeding in the second or third trimester. In some cases, a transvaginal ultrasound provides a clearer view of the placenta’s position. Treatment depends on the severity—minor cases may require rest and monitoring, while complete placenta praevia often necessitates a planned Caesarean section to ensure a safe delivery. Hospitalisation may be needed if heavy bleeding occurs, and blood transfusions or medications can help manage complications.

How can I prevent this in future pregnancies?

Unfortunately, there is no proven technique to avoid placenta praevia in future pregnancies. Understanding the risk factors and implementing preventive steps, on the other hand, can help lower the likelihood. Here are a few tips:

• Avoid smoking: Smoking during pregnancy is a major risk factor for placenta praevia.

• Maintain a healthy weight: Being overweight or obese raises the risk of several pregnancy problems, including placenta praevia.

• Maintain healthy haemoglobin levels: As blood loss is more than normal in such pregnancies, ensure your haemoglobin level is over 11gm/dl when you are in the ninth month.

• Early prenatal care: Regular prenatal check-ups can aid in detecting and managing any issues early on.

• Follow medical advice: Follow your doctor's suggestions for lifestyle modifications and other treatments. 

Stay calm and care 

With regular check-ups and expert guidance, most moms-to-be with placenta praevia deliver healthy babies. If you notice any unusual bleeding, especially in the second or third trimester, don't hesitate to reach out to your doctor. Early detection is crucial for a smooth pregnancy and a healthy delivery.

Frequently asked questions

Anchor Text: FAQs

1. Can I have sex if I have placenta praevia?

It's best to consult your doctor. They may advise against sexual activity, especially if you've experienced bleeding.

2. Can I exercise with placenta praevia?

Consult your doctor. Gentle exercises like walking may be okay, but strenuous activities should be avoided, especially if you've had bleeding.

3. How common is placenta praevia?

Placenta praevia affects about 0.3%-2% of pregnancies.

4. Can placenta praevia cause a miscarriage?

While placenta praevia doesn't directly cause miscarriage, it can lead to preterm labour and birth, which can increase the risk of complications, including miscarriage.