Placenta previa affects 1 in 200 pregnancies. It occurs when the placenta attaches to the uterine wall low in the womb and covers the cervix, blocking the baby’s exit from the womb.
While there is no set position as to where the placenta may attach itself to the uterine wall — and it can move upward as the baby grows — placenta previa can lead to bleeding during pregnancy and especially at delivery, where there is a serious risk of hemorrhage. While in cases of partial placenta previa a vaginal birth might be possible, in most cases it requires the mother to deliver via Cesarean section.
Here are some common questions about placenta previa including how to tell if you have it, risk factors for getting it, and placenta previa self-care for women diagnosed with it.
How Can I Tell if I Have Placenta Previa?
Placenta previa typically manifests itself with some painless spotting or bright red bleeding after 20 weeks gestation. An ultrasound, transvaginal scan, or MRI in the second trimester can confirm the diagnosis, but keep in mind that the problem can sometimes correct itself as the fetus grows and the placenta travels upward.
In cases of marginal placenta previa (placenta is at the edge of the cervix but not covering it) or partial placenta previa (covering a portion of the cervix), the problem is more likely to correct itself than when it is totally covering the cervix.
Sometimes the bleeding occurs randomly and other times, it may be triggered by sex or a medical exam. In some cases, the mother may not experience bleeding until labor, so it’s important to have at least one ultrasound and exam from your care provider before delivery.
In addition to spotting or bleeding, the mother might experience mild cramping or contractions in the abdomen, belly, or back.
What Causes Placenta Previa?
Researchers aren’t sure what causes placenta previa, but they do know the risk factors. A 2021 study notes the biggest risk factors as follows [*]:
- Previous uterine scars, from an earlier C-section (69.1%) or D&C (13.5%)
- Maternal age over 35 (53.8%)
- Having had 3 or more babies (63.5%)
- Assisted reproduction (IVF) (5.8%)
Other risk factors include:
- Smoking or use of cocaine during pregnancy
- Carrying multiples
- Maternal health (Diabetes or high blood pressure)
- A history of uterine fibroids
- Being pregnant with a boy
Is Placenta Previa Dangerous to the Mother or Baby?
Maternal complications associated with placenta previa include hemorrhage requiring blood transfusion, hysterectomy, placenta accreta or abruption, slowed growth of the fetus, birth defects, and bladder injury. Miscarriage is not typically associated with placenta previa because it occurs before placenta previa is typically diagnosed, at 20 weeks or thereafter. However, early delivery of the baby may be required.
More than half of the fetuses in the 2021 study experienced adverse outcomes such as prematurity, admission to a neonatal intensive care unit, and higher rates of perinatal mortality. Low birth weight and respiratory issues are also noted [*] [*].
How to Treat Placenta Previa
Unfortunately, there is no changing the position of the placenta in the womb. Care providers therefore try to get the mother as close to the due date as possible, but much depends on how bad the bleeding is, the gestational age of the fetus, its position in the womb, and the overall health of mother and baby.
Placenta Previa Dos and Don’ts
If your condition does not require immediate intervention, your care team may suggest a placenta previa care plan to minimize your risk of early delivery or bleeding with guidelines such as these:
- Seek medical care to diagnose, monitor, and manage the condition. This isn't something you can manage alone.
- Take it easy or rest in bed. In severe cases, bed rest in the hospital may be indicated.
- Have additional ultrasounds and prenatal monitoring. The placenta may move up and away from the cervix with the growth of the fetus.
- Consult with your care team to see what light exercise you can do. Walking might be one option, for instance.
- Avoid vaginal exams or penetration. This is to minimize bleeding.
- Take medication prescribed by your care team. This would be to avoid early labor or help the baby’s lungs develop faster. In cases of extreme bleeding, blood transfusions may be needed.
- Plan for delivery. To minimize the risks of having placenta previa in a future pregnancy, the March of Dimes cautions women to have a c-section only if it’s medically necessary [*].
- Ignore symptoms like cramping or bleeding, even if minor. These often signal placenta previa but can also be symptoms of other serious problems. There is a strong association between placenta previa and placenta accreta spectrum, where the placenta attaches too deeply to the uterine wall [*].
- Smoke cigarettes or use drugs. These have a deleterious effect on your health, your baby’s development, and your pregnancy.
- Run. This is likely to cause bleeding.
- Lift anything over 20 lbs. Try to avoid lifting small children, groceries, or packages.
- Exercise moderately or strenuously, especially after 20 weeks. Talk to your care team about what exercise you can do.
- Have sexual intercourse. You also want to avoid sexual activity that can lead to orgasm, the rationale being that transient uterine contractions may provoke bleeding [*].
- Use tampons or douche. Use a pad if you’re bleeding.
- Stand for more than a few hours. Occupational activities such as standing, lifting weight and strenuous exercise have been shown to contribute to preterm birth [*].
Can I Bank My Baby’s Cord Blood with Placenta Previa?
We recommend that you consult with your physician to see if they feel cord blood banking is possible with your delivery plan. Note: In most cases, cord tissue can be collected and stored, even when cord blood cannot be collected.
For more information on cord blood or cord tissue collection, processing, and benefits, request MiracleCord’s Free Info Kit.
The Bottom Line
Placenta previa is a serious condition that can lead to maternal death from hemorrhage and fetal complications as well. Be sure to talk to your care provider about any spotting, bleeding, or cramps you may be experiencing during your pregnancy, especially in the second and third trimester.
If you’ve been diagnosed with placenta previa, the condition may resolve on its own, but it must be monitored by your care team in order to carry your baby as close to term as possible and to determine whether the baby can be delivered vaginally.