Pregnancy Information Complications Bleeding

Vaginal bleeding during pregnancy should always be reported to your doctor. While spotting or bleeding does not always indicate a serious pregnancy complication, bleeding during pregnancy is not normal, and may be a sign of a number of serious pregnancy complications.

Causes of Spotting and Bleeding During Pregnancy

Early spotting and bleeding during pregnancy may be signs of a miscarriage or an ectopic pregnancy-one that occurs outside the cavity of the uterus. Bleeding and spotting later in a pregnancy may indicate placenta previa (or low lying placenta), or placental abruption.

Other causes of vaginal bleeding during pregnancy include trauma to the cervix or vagina (possibly due to intercourse), bleeding disorders, vaginal infections or cancer.

Placentia PreviaPlacenta Previa (Low Lying Placenta)

Spotting or bleeding during pregnancy may be a sign of placenta previa, or a low lying placenta. Placenta previa occurs when the placenta is connected to the uterus in a location that completely or partially blocks the cervical canal (the birth canal). A partial blockage of the cervical canal is more often called a low lying placenta.

Placenta previa affects one out of every two hundred pregnancies, and causes bleeding during pregnancy that can threaten both mother and child. Placenta previa and low lying placenta cases account for twenty percent of vaginal bleeding cases during late pregnancies.

Risks and Causes of Placenta Previa

The risk of placenta previa increases when a previous pregnancy ended with a cesarean section. A multiple pregnancy (twins, triplets, etc.) also increases the risk of a low lying placenta and bleeding during pregnancy. Older women are more likely to experience placenta previa than younger women. The risk also increases with each pregnancy: after six births, the chance of placenta previa is approximately five percent.

Other causes of placenta previa and low lying placenta include scars on the endometrial lining of the uterus (caused by surgery, cancer or other trauma), abnormal placenta formation or an unusually large placenta.

Bleeding During Pregnancy and Placenta Previa

Bleeding as a result of placenta previa usually occurs in the third trimester. Some spotting may be reported earlier in the pregnancy. Bleeding occurs suddenly, is severe, and is usually painless. Bleeding caused by placenta previa is a medical emergency that can cause major blood loss, shock or death if left untreated, and requires immediate treatment.

Placenta previa is diagnosed using ultrasound to determine the location of the placenta and the source of bleeding. Treatment of a low lying placenta depends on the severity of the bleeding and how close to term the pregnancy is. Depending on circumstances, treatment may focus on stabilizing the mother’s condition and stopping bleeding, or delivery by cesarean section.

Placental Abruption and Bleeding During Pregnancy

Placental abruption occurs when the placenta breaks free from the uterus, causing bleeding during pregnancy. The blood gathers in the uterus and often leaks out of the cervix, causing spotting and vaginal bleeding. The woman experiences severe pain and uterine contractions, increasing the risk of premature birth. Placental abruption bleeding occurs in one percent of pregnancies. Placental abruption occurs in a third of late pregnancies-those that continue past term.

Placenta Abruption Causes and Risks

Placental abruption bleeding and spotting is most often caused by maternal hypertension, high blood pressure during pregnancy. Smoking, alcohol and cocaine use can increase the risk of placental abruption. In addition, trauma or advanced maternal age may contribute to placental abruption and bleeding. In up to five percent of cases, no cause can be found.

Placental Abruption Treatment

Placental abruption treatment includes blood transfusions, intravenous fluid replacement and careful monitoring. Delivery may be early due to uterine contractions. A cesarean section may be required if there is evidence of fetal or maternal distress.

Complications of Placental Abruption

Placental abruption bleeding is usually mild, and bleeding is usually not a threat unless the condition continues to deteriorate. Maternal death due to placental abruption is uncommon in North America, although death rates may range as high as five percent in some parts of the world.

Fetal death rates are higher, ranging from 20 to 35 percent. Placental abruption prevents oxygen and nutrients from reaching the fetus, and in fifteen percent of cases no fetal heartbeat is detectable at hospital admission. Children who survive placental abruption experience health complications in approximately half of all cases.


Beers, M. H.,