Placenta previa, also known as low-lying placenta, is a condition that can occur in the womb before the baby is born. It occurs in roughly one out of 200 pregnancies. Placenta previa develops when the placenta attaches to the lower part of the uterine wall and partly or fully covers the cervix. When the cervix starts to open in preparation for labor, the placenta is detached, which can trigger severe vaginal bleeding. Most women with placenta previa deliver by Caesarian section. In the most serious cases, it can lead to mortality both for the mother and baby.
Abnormal Vaginal Bleeding
The most common symptom of placenta previa is abnormal vaginal bleeding. The bleeding associated with this condition usually occurs during the end of the second trimester or during the third trimester. The bleeding can vary from light to heavy and the color might be bright red. It usually stops, but reoccurs a few days or weeks later.
If you experience painless vaginal bleeding in the second or third trimester, it is important that you contact your doctor immediately as this could be a sign of placenta abruption. This is a serious condition where the placenta is coming off the uterine wall.
Some women do not experience any abnormal vaginal bleeding, In these cases, placenta previa is usually diagnosed by a routine ultrasound examination. In parts of the world where ultrasound is not available, it is not uncommon to confirm the diagnosis through surgery.
Cramping and Placenta Previa
Some women who have developed placenta previa also experience uterine cramping together with the vaginal bleeding. The cramping can cause painful and uncomfortable contractions. Cramping and placenta previa are linked together, but cramping during late pregnancy can also be caused by many other factors. It could be a sign of the ligaments stretching, premature labor or practice contractions. Because it is so difficult to tell what the cramps are caused by, it is always best to seek medical advice.
Placenta previa is more common among women who:
- Are over the age of 35
- Have had at least one baby
- Have had a C-section
- Are Asian
- Are carrying multiples
- Have had uterine surgery
- Have previously had placenta previa
Treatment for Placenta Previa
If the placenta covers a part or the entire cervix, the woman might be put on bed rest. If there is bleeding, admission to the hospital for careful monitoring is common. Sometimes blood transfusions are administered to replace maternal blood loss.
If the bleeding cannot be controlled, the baby is usually delivered regardless of the length of the pregnancy. Only a few women with marginal placenta previa will be able to deliver vaginally and most women will have a Caesarian section after 36 weeks gestation.
When to see the doctor
Consult your doctor if you experience any bleeding or cramping during your pregnancy.
Medicine Plus: Placenta Previa - https://www.nlm.nih.gov/medlineplus/ency/article/000900.htm
Penn Medicine: Placenta Previa - https://www.pennmedicine.org/health_info/pregnancy/000146.htm
Babycentre: Placenta Previa - https://www.babycentre.co.uk/pregnancy/complications/placentapraevia/