The placenta is the organ that develops during pregnancy to nourish the baby. It grows inside the uterine wall, connecting to the baby through the umbilical cord. Throughout your pregnancy, the placenta is responsible for getting nutrients and oxygen into your baby’s bloodstream, as well as removing its waste products.
In rare cases, a pregnancy might take on some additional risks, due to abnormalities in the placenta.
The placenta grows from the point at which the fertilized egg implanted in the uterus. Normally, this happens on the inside wall or ceiling of the uterus. In a condition called placenta previa, the placenta grows from the lower side of the uterus. The placenta then grows to cover the cervix, causing problems for delivery.
Symptoms and diagnosis
Placenta previa is often diagnosed in the third trimester, following an occurrence of bright red vaginal bleeding. The bleeding can be heavy or light, and it usually stops on its own, only to return again within a few days or weeks. Most women don’t experience any pain.
Your OB-GYN can diagnose placenta previa with a routine ultrasound during a prenatal appointment.
Placenta Previa Complications
Placenta previa can cause severe, even life-threatening bleeding during labor, vaginal birth, or even immediately after delivery. In some cases, there is an increased risk of preterm birth and/or Cesarean delivery.
Your doctor will evaluate the severity of your condition and make a recommendation based on your individual case. For mild bleeding, your doctor will likely recommend bed rest, and advise you to avoid both sex and exercise. For heavier bleeding, you may need to remain on strict bed rest in the hospital.
Placenta Accreta, Increta, and Percreta
Normally, the placenta easily detaches from the uterine wall, so that it can be expelled after the baby is born. This is known as the “afterbirth.” However, in rare cases, the placenta remains attached because its blood vessels have grown too deeply into the uterine wall. This is called placenta accreta.
Placenta accreta can worsen if the blood vessels have impacted into the uterine muscles (called placenta increta), or if they have penetrated through the walls of the uterus (placenta percreta).
Placenta previa, accrete, and percreta typically have no outward symptoms. Your doctor can catch the condition during a regular ultrasound, MRI, or blood test.
Placenta previa and its variants can cause excessive blood loss after birth. Your blood may have difficulty clotting normally, and this could lead to lung and kidney failure. Placenta previa also increases the risk of preterm labor and premature birth.
Treating severe blood loss in labor usually involves a blood transfusion. When the outcome is difficult to control, your doctor may recommend an early delivery to try to prevent you from going into labor naturally.
Vasa previa is a complication in which fetal blood vessels, either in the placenta or in the umbilical cord, are trapped between the baby and the cervix. This can happen in a number of ways. One of the most common is when the placenta develops a minor (succenturiate) lobe, joined to the main placental disc only by threads of blood vessels, which cross the cervical opening.
Symptoms and diagnosis
There are usually no symptoms to signal vasa previa, but the condition can be detected with a sonogram and a Doppler ultrasound after the 16th week.
Vesa previa typically causes no problems for either the mother or baby, until the water breaks. This can tear the blood vessels, resulting in the baby losing a life-threatening amount of blood.
Vesa Previa Management
To prevent a fatal outcome for the baby, it is crucially important is to detect vasa previa before going into labor. Your OB-GYN will probably recommend a C-section a few weeks before your due date to avoid the dangers of natural labor.