Placenta previa

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Placenta previa is when you placenta is lying low in your uterus next to or covering your cervix- the doorway between the uterus and the vagina.  The placenta is usually located near the top of the uterus.. It supplies the fetus with nutrients through the umbilical cord and removes its waste.Placenta previa can cause severe bleeding before or during delivery.When found early placenta previa is usually not considered to be a problem because as the uterus grows, the placenta usually moves higher in the uterus, away from the cervix. But later in pregnancy if the placenta is still covering the cervix , then it becomes a problem.You may be restricted to bed rest for a portion of your pregnancy. If you have placenta previa at the time of delivery, you will need a c- section.

The placenta may lie near the cervix and not cover it and this is low-lying placenta. It usually moves up as pregnancy progresses. Placenta may also partially cover the cervix as in partial previa or fully cover and block the cervical opening as in the case of complete previa.



The actual cause of placenta previa in unknown. The placenta grows wherever the embryo implants itself in the uterus. If the embryo implants itself  in the lower portion of the uterus, the placenta will grow there and might cover the cervix. Placenta previa is usually diagnosed during the second trimester ultrasound. Other conditions like abnormally shaped uterus, scars in the lining of the uterus and a large placenta can also cause placenta previa.



Certain factors that can put a woman at risk of getting placenta previa include

  • having had a previous placenta previa in previous pregnancy
  • had some uterine surgery (such as a D&C or fibroid removal).
  • pregnant with multiples
  • a previous c – section
  • older than 35 years
  • cigarette smoker
  • asian



The main symptoms of placenta previa is bright red vaginal bleeding which is usually painless during the second trimester. The bleeding may be light or heavy and may resolve on its own without any medication. Bleeding may however recur days or weeks later. Other women may also experience contractions.



An ultrasound is usually used to diagnose placenta previa.  An abdominal and vaginal ultrasound will reveal placenta previa. Rarely a magnetic resonance imaging (MRI) may be used to determine the location of the placenta.



Treatment for placenta previa may depend on the individual’s condition such as how far along you are in pregnancy, amount of bleeding, position of placenta, your health and baby’s health.

If you have little or no bleeding, you may be put on bed rest for the rest of your pregnancy . Standing for long periods and physical exercise is off limits.You may also be told to avoid sex. For partial previa , you may be allowed to attempt vaginal delivery but if heavy bleeding occur, you will need an emergency c C-section.

In the case of heavy bleeding, you may need hospitalization. You will be put on bed rest, get blood transfusion to replace lost blood and medication to avoid premature labor may be administered. The latest you will deliver will be 37 weeks but may be earlier if necessary.

If bleeding however doesn’t stop and your baby is in distress, you will be given delivered through emergency c section even if baby is premature.



Placenta previa may present  complications such as

  • bleeding
  • preterm birth



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