Placenta Previa – Causes, Symptoms, Treatment, And More

Placenta previa is a serious pregnancy complication where the placenta, the organ that nourishes the baby, partially or entirely covers the cervix —the opening to the uterus. This can create significant risks for both the mother and baby, especially as the pregnancy progresses and during delivery. 

It’s important to understand the causes of placenta previa, recognize the symptoms of placenta previa, and know the treatment options available to manage it effectively.

What Is Placenta Previa?

Placenta previa occurs when the placenta is abnormally positioned in the uterus, covering all or part of the cervix. The cervix is the lower part of the uterus that opens into the vagina and serves as the birth canal during delivery. 

Normally, the placenta attaches to the upper part of the uterus, away from the cervix. However, in placenta previa, this attachment is lower, leading to potential complications as the pregnancy advances.

Types Of Placenta Previa

This pregnancy complication can be categorized based on how much of the cervix it covers:

1. Complete (Total) placenta previa: The placenta completely covers the cervical opening.
2. Partial placenta previa: The placenta covers part of the cervical opening.
3. Marginal placenta previa: The placenta is located near the edge of the cervix but doesn’t cover it.
4. Low-lying placenta: The placenta is positioned lower in the uterus and might move away from the cervix as the pregnancy continues.

Causes Of Placenta Previa

The exact reasons for placenta previa aren’t completely understood, but several factors can increase the risk:

• Previous cesarean section: Women who have had one or more C-sections are at higher risk. Scar tissue from the surgery may affect where the placenta implants.
• Multiple pregnancies: Carrying twins, triplets, or more increases the risk due to the larger placental area needed.
• Advanced maternal age: Women over 35 are more likely to experience placenta previa.
• History of this complication: If you’ve had placental position complications in a previous pregnancy, there’s a higher chance it will happen again.
• Uterine surgery: Previous surgeries on the uterus, like D&C (dilation and curettage) or myomectomy (removal of fibroids), can increase the likelihood.
• Smoking and substance abuse: Smoking and drug use during pregnancy are associated with a higher risk of placenta previa.
• In Vitro Fertilization (IVF): Pregnancies conceived through IVF have a higher incidence of placental position complications.

Symptoms Of Placenta Previa

The most common symptom of placenta previa is painless vaginal bleeding during the second or third trimester. This bleeding can be light or heavy and might occur without any warning. Key characteristics include:

• Timing: Usually starts after the 20th week of pregnancy.
• Pain: Typically, there’s no pain, but some women might experience mild cramping or contractions.
• Recurrent episodes: Bleeding may stop on its own but can happen again in the following days or weeks.

In some cases, women with placenta previa might not have any symptoms, and the condition is only discovered during a routine ultrasound.

How To Diagnose Placental Position Complications?

Placental position complications are usually diagnosed through an ultrasound, which can be either transabdominal or transvaginal:

• Transabdominal ultrasound: The most common method, where the ultrasound probe is placed on the abdomen to see the position of the placenta.
• Transvaginal ultrasound: In some cases, this method, where the probe is inserted into the vagina, provides a clearer view of the cervix and placenta.

Most of the time, placenta previa is diagnosed during the mid-pregnancy anatomy scan, typically performed between 18 and 20 weeks. Sometimes, a low-lying placenta detected early in pregnancy might move upward as the uterus grows, resolving the issue without needing any intervention.

Treatment Of Placenta Previa

How this pregnancy complication is treated depends on the severity of the condition, how far along the pregnancy is, how much bleeding there is, and the health of both the mother and baby.

1. Conservative Management

For many women, if placental position complications are detected early and there’s minimal or no bleeding, treatment is often conservative. This means taking steps like avoiding activities that could cause bleeding, such as sex or inserting anything into the vagina. Resting more and reducing physical activity is also advised, especially if any bleeding occurs. Regular ultrasounds will be done to keep an eye on the placenta’s position and the baby’s growth.

2. Hospitalization

If the bleeding is significant or keeps coming back, hospitalization might be necessary. In such cases, the mother and baby are closely monitored, with frequent checks on vital signs, fetal heart rate, and the amount of bleeding. If preterm delivery is expected, doctors may give corticosteroids to speed up the baby’s lung development. In cases of severe bleeding, blood transfusions might be needed to manage maternal anemia and stabilize the mother’s condition.

Delivery Planning – Timing And Method

Deciding when and how to deliver the baby is critical in managing placental position complications. Most women will need a C-section to avoid dangerous bleeding during labor. Typically, delivery is scheduled around 36-37 weeks if everything is stable. But if severe bleeding occurs earlier, an emergency C-section might be necessary, regardless of how far along the pregnancy is.

If the bleeding can’t be controlled, delivering the baby early might be the safest option, even though it means dealing with the risks of prematurity.

4 Severe Risks Associated With Placenta Previa

Placenta previa can lead to several complications, including:

1. Preterm birth: If early delivery is needed because of uncontrolled bleeding, the baby may face the risks associated with prematurity, such as respiratory distress and developmental delays.
2. Maternal hemorrhage: Severe bleeding is the biggest risk for the mother and can lead to shock, anemia, and the need for blood transfusions.
3. Placenta accreta: In some cases, the placenta can grow too deeply into the uterine wall (placenta accreta), causing severe bleeding during delivery. This may require a hysterectomy (removal of the uterus) to control the bleeding.
4. Fetal growth restriction: Reduced blood flow to the placenta can lead to intrauterine growth restriction (IUGR), resulting in a smaller-than-average baby at birth.

Prevention Of Placental Position Complications

While there’s no guaranteed way to prevent this pregnancy complication, there are steps you can take to lower the risk. Quitting smoking and avoiding substance abuse during pregnancy is important. Regular prenatal check-ups are also vital for monitoring your and your baby’s health, which helps in catching any issues early. Additionally, being cautious about unnecessary uterine surgeries can help reduce the chances of placenta previa in future pregnancies.

Final Thoughts

Managing placental position complications effectively hinges on staying informed and working closely with your healthcare provider. Advances in prenatal care offer improved detection and treatment, enhancing outcomes. Staying proactive with prenatal visits, recognizing symptoms, and preparing for possible complications are essential. Open communication with your healthcare team is crucial for navigating this condition and ensuring a safe delivery.