Placenta Previa Bleeding in Pregnancy

1. Total placenta previa – This occurs when the placenta completely covers the opening of the uterus.
2. Partial placenta previa – This condition occurs when the placenta  attaches partially over the cervix
3. Marginal placenta previa – This occurs when the placenta  attaches near the edge of the cervix

Why is Placenta Previa a Concern?

As mentioned previously, placenta previa could cause bleeding in the latter part of the pregnancy, and this is one of its biggest risks. As the baby grows bigger and you progress into the third trimester, the lower uterine wall begins to thin out. This happens in preparation for labor.

During this phase, the area of the placenta that is closer to the lower uterine wall and the uterine OS (cervical opening of the uterus) bleeds. The amount of placenta that covers the cervix determines the amount of bleeding that could take place. Hence, it is in the best interest of the mother that the placenta is away from the cervix to avoid bleeding associated with placenta previa.

Is it Dangerous to Have Placenta Previa?

Placenta previa comes with its set of risks and complications. Apart from bleeding during the second and third trimester, placenta previa could lead to the following:

1. The placenta may not implant well into the uterus as it ideally should.
2. Preterm birth – the baby could be born before the completion of 37 weeks of pregnancy.
3. The slow growth of the fetus
4. Birth defects

What Are the Causes of Placenta Previa?

Placenta previa generally occurs in late pregnancy, that is, after the 20th week of pregnancy. The exact causes of placenta previa cannot be ascertained, but the condition can be attributed to the following reasons:

• Uterine scarring during previous pregnancies and childbirth
• Fibroids in the uterus are benign, but resemble tumors
• Advanced maternal age, that is women who are above the age of 35 years
• Pregnant women who have had a previous cesarean section, uterine surgeries, or miscarriages
• Women belonging to minority races
• Women who have other uterine abnormalities
• Smoking cigarettes
• Women who have experienced placenta previa in their previous pregnancies
• Being pregnant with twins or multiples
• An abnormally sized and shaped uterus

Does it Lead to Placental Abruption?

Placenta previa does not directly lead to placental abruption. Direct trauma to the uterus, such as a bad fall, a motor vehicle accident, and the like could lead to placental abruption. However, one or more of the following factors can trigger placental abruption:

• Cigarette smoking
• Sickle cell anemia
• Multiple pregnancies
• Previous delivery from placental abruption and
• Hypertension

How is Placenta Previa Diagnosed?

If you spot vaginal bleeding during and after the second trimester, you must visit your gynecologist to ascertain the true causes of the bleed.  The doctor diagnoses placenta previa after a thorough physical examination and transabdominal ultrasound test. The ultrasound can find the location of the placenta in relation to the cervix.

If the results are inconclusive, a transvaginal ultrasound can be performed to confirm the amount of the placenta that is covering the cervix. Magnetic resonance imaging (MRI) can also determine the location of the placenta.

It is important to note that the ultrasound can detect a low-lying placenta early in your pregnancy. However, it could move away from the cervix with upwards movements, as you progress through your pregnancy. This process is placental migration.

How is Placenta Previa Treated?

While it is important to determine the location of the placenta in relation to the cervix, it is noteworthy to mention that the position of the placenta cannot be changed or altered. Hence, placenta previa needs treatment with utmost care to ensure proper growth and delivery of the baby. Your doctor might advise bed rest or hospitalization. Your doctor will treat your condition with the necessary medications, depending on your tolerance for medications, and other therapies

Since most placenta previa patients need a cesarean section, your doctor will take a call on when to perform the surgery.  The doctor will consider the gestational age of the baby, their condition, and the amount of bleeding. In severe cases, where blood loss has been significant, the doctor will go ahead with blood transfusion.