This condition is called placenta previa and is a main cause for vaginal bleeding in the second and third trimester of pregnancy. If undiagnosed, the condition could lead to uncontrolled bleeding and death of both the baby and mother.

However, the condition is fairly uncommon, occurring at a rate of 1 out of 200 deliveries in the United States.

Healthy Placenta vs. Placenta Previa

The placenta is a flat oval in shape and located on the outside wall the uterus. As you probably know, the placenta is in charge of delivering nutrients to your baby via the umbilical cord. It can be low-lying in the beginning of pregnancy. By the time a normal uterus is ready to deliver the baby the placenta has shifted to the top of the uterus.

In some pregnancies, the placenta is located on the side or bottom of the uterus. If the opening or os of the cervix is completely blocked, it’s termed total placenta previa. Partial placenta previa is when the placenta partially covers of the cervix, and marginal placenta previa means the placenta is near the edge of the cervix, but not covering the opening. 
If you’re diagnosed during this ultrasound, you don’t have to become frantic quite yet. Some cases of placenta previa correct during the growth and expansion of the uterus during the third trimester. How, you wonder? The placenta is anchored to the uterine wall, and as the uterus expands, the placenta may be shifted away from the cervix.

Who Is At Risk? 
There is a definite population of women who tend to be more at risk for placenta previa:

• Women with multiple pregnancies such as twins, triplets
• Having a uterus that is abnormal in shape
• Women with fibroid tumors past or present
• Women over 30
• Women with previous scarring of the uterus caused by surgery, past pregnancies or abortion

Symptoms and Treatment of Placenta Previa 
The only symptom is painless bleeding later in the second or third trimester. The bleeding may range from spotting to a heavy flow of bright red blood. The spotting may or may not stop without intervention, so make sure you alert your doctor.

How your case is treated will depend on many factors. However, you can assume sexual intercourse will be out of the picture until your baby is delivered. Your doctor will probably not do any more pelvic exams to limit the intrusion into your vagina, which can cause more bleeding. However, as long as you follow your doctors orders, you and your baby should remain healthy and happy.