This obstetric complication involves painless vaginal bleeding during third-trimester of pregnancy (20th week) secondary to an abnormal placentation near or extending the inner cervical opening. It temporarily joins the mother with the fetus to provide oxygen and essential nutrients. Placenta previa can be life threatening to both the fetus and the mother due to the underlying hemorrhage risk.
- Low lying placenta
- Partial placenta
- Marginal placenta
- Complete placenta
Low lying placenta- When placenta covers the lower uterine segment and does not extend through the internal opening of the cervix.
Partial placenta- When the placenta partially extends through the cervical opening.
Marginal placenta- Here placenta does not cover the cervical opening but is located adjacent to it.
Complete placenta- When the placenta totally extends through the opening from the uterus to the cervix.
Generally, Placenta previa is found in 1 out of 200 pregnant women.
There are more chances in women who have;
- History of multiple pregnancies twins or triplets
- Frequently many episodes of pregnancies
- Old age pregnancy
- Smoking or use of cocaine.
- Abnormal shape or size of uterus
- Scarring of uterus lining due to C-section, D&C, fibroid removal or abortion
- In vitro fertilization
Symptoms and Complications
Placenta previa usually occurs during 2nd or 3rd trimester with a painless bright red vaginal bleeding that ranges from light to heavy and may also be accompanied with light contractions.
Major complications involved are;
Severe Bleeding: This can be life threatening which leads to hemorrhage, shock or even death.
Pre-term Delivery: Severe bleeding may lead to the complications of pre-term delivery. Therefore, an emergency C-section can be performed before full term.
Placenta accrete: This major complication may arise when the placenta deeply attaches itself to the uterine wall and sometimes it becomes a serious issue that leads to surgical removal of the uterus (hysterectomy).
Diagnosis and Treatment
Placenta previa is commonly diagnosed during the second trimester with a routine ultrasound or an occurrence of vaginal bleeding.
Mostly the treatment option depends upon the stage of pregnancy and condition of mother and fetus health.
No treatment is required when it is diagnosed in the second trimester. As general approach during this time the treatment aims to prolong pregnancy and easing symptoms.
In an emergency when the mother is suffering from heavy bleeding or risk of fetus life, a C-section may be performed at any stage.
Placenta previa can be life-threatening to both mother and baby.
Therefore, a patient should contact the doctor immediately when vaginal bleeding occurs during pregnancy.