Placenta previa is a pregnancy complication that occurs in 1 out of every 200 pregnancies according to CureResearch.com. Placenta previa is serious because it can cause excessive bleeding before or during delivery of the baby.
What is the placenta?
The placenta is a very important organ of pregnancy. It provides the baby with oxygen, and nutrients and removes waste products from the baby’s blood. The placenta is attached to the wall of the uterus, and to the baby’s umbilical cord.
Placenta previa occurs when the placenta attaches to the lower part of the uterine wall and either partially or totally covers the cervix. During labor the cervix opens so the baby can be born. When the cervix dilates the placenta detaches because it is over the cervix. Severe vaginal bleeding can result. Thankfully most women receive good prenatal care in which this condition can be detected before labor starts.
How is placenta previa detected?
During the second half of pregnancy, bright red vaginal bleeding may signal placenta previa.
Placenta previa can also be detected by ultrasound.
Contractions can also occur with the bleeding during the end of the second trimester. The bleeding can start and stop and may be light or heavy.
Placenta previa can be total (covers the entire cervix), partial (covers part of the cervix) or it can be marginal (covers only the edge of the cervix).
A doctor may determine that a placenta is low-lying but not close enough to qualify as marginal placenta previa. A woman with low-lying placenta will not have bleeding during the pregnancy but may experience bleeding after delivery.
Women diagnosed with placenta previa are told not to have sex for the remainder of the pregnancy as having sex can cause bleeding. Examining the cervix during pregnancy can also cause bleeding.
Women are at increased risk for placenta previa if they have scarring in the lining of the uterus known as endometrium, a large placenta such as when there is a multiple pregnancy, or if they have an abnormally shaped uterus. Women who have had previous c-sections are also at increased risk for placenta previa. Women who have had placenta previa in a previous pregnancy are more likely to have it again. Pregnant women over the age of 35 are at greater risk for placenta previa. Asian women and those who smoke are also at increased risk as well as women pregnant with more than one baby. Women who have had uterine surgery such as a dilation and curettage (D and C) or a myomectomy to remove uterine fibroids are at increased risk for placenta previa.
Women with placenta previa run the risk of severe vaginal bleeding which can put her life and her baby’s life in jeopardy if she hemorrhages before delivery. She could also bleed during labor or up to several hours after delivering the baby. If the woman starts to hemorrhage severely during pregnancy she may have to have an emergency C-section that may result in premature birth of the baby if it occurs before the 38th week of pregnancy. Premature birth puts the baby at risk for health issues. Sometimes the placenta implants too deeply into the uterine wall or attaches to the bladder, which is an uncommon condition known as placenta accreta. Severe bleeding may result when the placenta does not detach normally during delivery causing severe bleeding.
Close monitoring of the pregnancy and a hospital birth is necessary when placenta previa is detected.
Mayo Clinic Placenta Previa http://www.mayoclinic.com/health/placenta-previa/DS00588/DSECTION=complications
CureResearch.com Basic Summary for Placenta previa http://www.cureresearch.com/p/placenta_previa/basics.htm