What is the placenta?
The placenta is an organ that grows on the inside, upper part of your uterus (womb) when you're pregnant
It has many large blood vessels to carry oxygen and nutrients from you to the fetus (baby)
The placenta's blood vessels form the umbilical cord to connect the placenta to the fetus
About 15 minutes after you deliver your baby, the placenta comes off your uterus and goes out your vagina
That's why it's also called the "afterbirth"
What is placenta previa?
Placenta previa is when the placenta attaches too low in your uterus, over or near your cervix
Your cervix is the lower part of your uterus. It has an opening that normally stays closed while you're pregnant. When your baby is ready to be born, the cervix opens (dilates) to let your baby out. If you have placenta previa, the placenta gets in the way.
Placenta previa often gets better on its own before delivery
If it doesn’t get better before delivery, your baby could tear the placenta as your baby moves through the cervix into the birth canal (vagina), causing very bad bleeding
If you have placenta previa, wait to have sex until after your baby is born—having sex while you have placenta previa can cause bleeding
Problems With the Placenta
Normally, the placenta is located in the upper part of the uterus, firmly attached to the uterine wall until after delivery of the baby. The placenta carries oxygen and nutrients from the mother to the fetus.
In placental abruption (abruptio placentae), the placenta detaches from the uterine wall prematurely, causing the uterus to bleed and reducing the fetus’s supply of oxygen and nutrients. Women who have this complication are hospitalized, and the baby may be delivered early.
In placenta previa, the placenta is located over the cervix, in the lower part of the uterus. Placenta previa may cause painless bleeding that suddenly begins after 20 weeks of pregnancy. The bleeding may become profuse. The baby is usually delivered by cesarean.
What are the symptoms of placenta previa?
Sudden, painless, bright red bleeding late in pregnancy
Call your doctor right away if you're pregnant and have vaginal bleeding—your life and your baby’s life could be in danger
How can doctors tell if I have placenta previa?
Doctors suspect placenta previa if you have vaginal bleeding that starts after 20 weeks of pregnancy
They’ll do an ultrasound Ultrasonography Ultrasonography is a safe imaging test that uses sound waves to create a moving picture of the insides of your body. Ultrasonography doesn't use radiation (x-rays). Ultrasonography is also called... read more to tell for sure—this test uses sound waves to create moving pictures of the insides of your uterus
During the ultrasound, they’ll also check to make sure your placenta hasn’t pulled away from your uterus early (placental abruption Placental Abruption The placenta is an organ that grows on the inside, upper part of your uterus (womb) when you're pregnant It has many large blood vessels to carry oxygen and nutrients from you to the fetus ... read more )
How do doctors treat placenta previa?
If doctors think your baby's lungs are developed enough to be delivered safely (usually after 36 weeks of pregnancy), they'll do:
Surgery to deliver your baby, called a cesarean section (C-section Cesarean Delivery (C-Section) A C-section is surgery to deliver your baby through a cut made in your belly and uterus. For a cesarean delivery, an incision is made in the abdomen and into the uterus. This incision is usually... read more )
Doctors try to do the C-section before you go into labor. Going into labor may trigger bleeding.
If you’re bleeding before 36 weeks of pregnancy:
Doctors will usually have you stay in the hospital on bed rest to see if the bleeding stops
Doctors will monitor your baby's heart rate
If the bleeding stops, you may be able to go home, but you’ll have to be ready to go back to the hospital quickly if you start bleeding again
If the bleeding doesn't stop or your baby's heart rate is abnormal, they'll do a C-section
If doctors think you need to deliver early, they may take a sample of the fluid around your baby (amniotic fluid). Doctors can run tests on the fluid to tell if your baby's lungs have grown enough for you to deliver.