What Is Placenta Previa?

What Is Placenta Previa?
Nelton Ramos

Reviewed and approved by the doctor Nelton Ramos.

Last update: 27 December, 2022

Placenta previa is a disorder that occurs during pregnancy. Placenta previa means the placenta becomes implanted in a lower position than normal in the uterus. In some cases, the placenta may cover one side of the cervix or the complete cervical opening.

Placenta previa has many different symptoms, the most common however is painless bleeding during the third trimester of pregnancy.

This disorder mainly affects the placenta which is an oval-shaped organ. It is usually located near the top of the uterus. The placenta’s main function is to nourish the baby through the umbilical cord.

According to specialists, placenta previa is an issue during the first trimesters of pregnancy. As the pregnancy progresses, the placenta grows and gets closer to the cervix. T his can cause many complications including hemorrhaging.

These complications may require an advanced delivery or cesarean section.

Different types of placenta previa

Doctors divide placenta previa into 4 categories:

  • If the placenta completely covers the cervix, it is known as complete or total placenta previa.
  • If the placenta is near the edge of the cervix it is known as marginal placenta previa.
  • Partial placenta previa refers to when the placenta only covers part of the cervical opening. This only occurs when the cervix begins to dilate.
  • If the edge of the placenta doesn’t come in with the cervix it is known as low placenta previa.

Doctors can find the location of the placenta through an ultrasound. This test is usually carried out between the 16th and 20th week of pregnancy.

What Is Placenta Previa?

What should you do if you’re diagnosed with placenta previa?

The treatment of placenta previa depends on how advanced the pregnancy is. Avoid being alarmed if the second trimester ultrasound indicates a placenta previa since, as your pregnancy progresses, the placenta may move away from the cervix and, therefore, it ceases to be a problem.

Although the placenta takes hold in the uterus and remains there, it can slowly move away from the cervix as the uterus expands. As the placenta grows, it is most likely to go to the upper part of the uterus where the blood flow is greater

As the pregnancy progresses, the placenta grows and gets closer to the cervix and this can cause many complications including hemorrhaging.


One of the most effective recommendations when it comes to placenta previa is to be relaxed and calm. While you’re pregnant, you should be calm and joyful. Avoid activities that require lifting heavy weights or unnecessary effort in general. These activities increase the risk of hemorrhages.

Keep in mind that there are no specific causes of placenta previa. Some experts believe however, that it has to do with vascular issues that occur in the endometrium. The endometrium is the inner layer of the uterus.

Experts have been able to confirm however, that there are various factors that can contribute to the occurrence of placenta previa.

What Is Placenta Previa?

Risk factors:

  • Frequent pregnancies with spontaneous abortions.
  • Smoking or drug addiction.
  • Getting pregnant at an older age.
  • Uterine lesions from previous pregnancies.
  • Multiple cesarean sections.
  • Twin pregnancies.

Although there is no specific medication to treat it, in some cases, where there isn’t a lot of bleeding, doctors administer tocolytics. In addition, patients with a diagnosis of placenta previa should always have a good intake of iron and folic acid in order to prevent bleeding.

Women with placenta previa may experience more than one episode of bleeding during their pregnancy. Doctors sometimes consider the option of hospitalizing the mother until the moment of delivery in order to avoid placental detachment.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Dulay, A. Placenta previa. Manual MSD- Versión para profesionales. [En línea].
  • Gordon: Obstetrics Gynecology & Infertility. 5th Edition. Scrub Hill Press Inc. 2001.
  • Lambrou: The Johns Hopkins Manual of Gynecology and Obstetrics. Lippincott Williams & Wilkins, Philadelphia. 1999.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.