Late Pregnancy Bleeding

Common problems that cause light bleeding include an inflamed cervix or growths on the cervix. These may be treated with medication. Heavy bleeding usually involves a problem with the placenta.

The two most common causes at this time are placental abruption and placenta previa.

Preterm labor also can cause such bleeding.

Placenta Abruption

The placenta is attached to the uterine wall. It may detach from the wall before or during labor. This may cause vaginal bleeding. It often causes pain, even if bleeding is light or not seen. When the placenta becomes detached, the fetus may get less oxygen.

Blood flow to the pregnant uterus is significantly increased and severe abruption is a true medical emergency that requires prompt attention and delivery.

A complication of pregnancy, wherein the placental lining has separated from the uterus of the mother prior to delivery. It is the most common pathological cause of late pregnancy bleeding. In humans, it refers to the abnormal separation after 20 weeks of gestation and prior to birth.

It occurs on average in 0.5%, or 1 in 200, deliveries. Placental abruption is a significant contributor to maternal mortality worldwide; early and skilled medical intervention is needed to ensure a good outcome. Treatment depends on how serious the abruption is and how far along the woman is in her pregnancy.

Placental abruption has effects on both mother and fetus. The effects on the mother depend primarily on the severity of the abruption, while the effects on the fetus depend on both its severity and the gestational age at which it occurs. The heart rate of the fetus can be associated with the severity.


The exact cause of a placental abruption may be hard to determine. Direct causes are rare, but include:

–     Injury to the belly area (abdomen) from a fall, hit to the abdomen, or automobile accident.

–     Sudden loss of uterine volume (can occur with rapid loss of amniotic fluid or after a first twin is delivered).

Risk Factors

–     Blood clotting disorders (thrombophilias).

–     Cigarette smoking.

–     Cocaine use.

–     Diabetes.

–     Drinking more than 14 alcoholic drinks per week during pregnancy.

–     High blood pressure during pregnancy (about half of placental abruptions that lead to the baby’s death are linked to high blood pressure).

–     History of placenta abruption.

–     Increased uterine distention (may occur with multiple pregnancies or very large volume of amniotic fluid).

–     Large number of past deliveries.

–     Older mother.

–     Premature rupture of membranes (the bag of water breaks before 37 weeks into the pregnancy).

–     Uterine fibroids.

Placental abruption, which includes any amount of placental separation before delivery, occurs in about 1 out of 150 deliveries. The severe form, which can cause the baby to die, occurs only in about 1 out of 800 to 1,600 deliveries.


–     Abdominal pain.

–     Back pain.

–     Frequent uterine contractions.

–     Uterine contractions with no relaxation in between.

–     Vaginal bleeding.

Exams and Tests

Tests may include:

–     Abdominal ultrasound.

–     Complete blood count.

–     Fetal monitoring.

–     Fibrinogen level.

–     Partial thromboplastin time.

–     Pelvic exam.

–     Platelet count.

–     Prothrombin time.

–     Vaginal ultrasound.


Treatment may include fluids through a vein (IV) and blood transfusions. The mother will be carefully monitored for symptoms of shock. The unborn baby will be watched for signs of distress, which includes an abnormal heart rate.

An emergency cesarean section may be needed. If the baby is very premature and there is only a small placental separation, the mother may be kept in the hospital for close observation. She may be released after several days if the condition does not get worse and any bleeding stops.

If the fetus is developed enough, vaginal delivery may be done if it is safe for the mother and child. Otherwise, a cesarean section will be done.

Outlook (Prognosis)

The mother does not usually die of this condition. But any of the following increases the risk of death for both the mother and baby:

–     Closed cervix.

–     Delayed diagnosis and treatment of placental abruption.

–     Excessive blood loss, leading to shock.

–     Hidden (concealed) uterine bleeding in pregnancy.

–     No labor.

Fetal distress occurs early in the condition in about half of all cases. Infants who live have a 40-50% chance of complications, which range from mild to severe.

Possible Complications

Excess blood loss can lead to shock and possible death of the mother or baby. If bleeding occurs after the delivery and blood loss cannot be controlled in other ways, the mother may need a hysterectomy (removal of the uterus).


–     Do not drink any alcohol, such as beer and wine.

–     Do not smoke or use recreational drugs during pregnancy. Get early and regular prenatal care.

–     Recognizing and managing conditions in the mother such as diabetes and high blood pressure also decrease the risk of placental abruption.

Placenta Previa

Occurs when a baby’s placenta partially or totally covers the opening of the cervix, which is the lower end of the uterus that connects to the top of the vagina.

Signs & Symptoms

Women with placenta previa often present with painless, bright red vaginal bleeding. This commonly occurs around 32 weeks of gestation, but can be as early as late mid-trimester. This bleeding often starts mildly and may increase as the area of placental separation increases. Previa should be suspected if there is bleeding after 24 weeks of gestation. Women may also present as a case of failure of engagement of fetal head.


Exact cause of placenta previa is unknown. It is hypothesized to be related to abnormal vascularisation of the endometrium caused by scarring or atrophy from previous trauma, surgery, or infection. These factors may reduce differential growth of lower segment, resulting in less upward shift in placental position as pregnancy advances.

Risk Factors

–     Maternal age ≥ 40 (vs. < 20).

–     Previous placenta previa (recurrence rate 4-8%), caesarean delivery, myomectomy or endometrium damage caused by D&C.

–     Alcohol use during pregnancy was previous listed as a risk factor, but is discredited by this article.

–     Women who have had previous pregnancies, especially a large number of closely spaced pregnancies, are at higher risk due to uterine damage.

–     Smoking during pregnancy.

–     Illicit drugs – cocaine use during pregnancy.

–     Women who are younger than 20 are at higher risk and women older than 35 are at increasing risk as they get older.

–     Women with a large placenta from twins or erythroblastosis are at higher risk.

–     Race is a controversial risk factor, with some studies finding that people from Asia and Africa are at higher risk and others finding no difference.

–     Placental pathology (vellamentous insertion, succinturiate lobes, bipartite, i.e. bilobed placenta etc.).


An initial assessment to determine the status of the mother and fetus is required. Although mothers used to be treated in the hospital from the first bleeding episode until birth, it is now considered safe to treat placenta previa on an outpatient basis if the fetus is at less than 30 weeks of gestation, and neither the mother nor the fetus are in distress. Immediate delivery of the fetus may be indicated if the fetus is mature or if the fetus or mother is in distress. Blood volume replacement (to maintain blood pressure) and blood plasma replacement (to maintain fibrinogen levels) may be necessary.

The corticosteroids are indicated at 24–34 weeks gestation if the patient has bleeding, given the higher risk of premature birth.

Mode of Delivery

The mode of delivery is determined by clinical state of the mother, fetus and ultrasound findings. In minor degrees (traditional grade I and II), vaginal delivery is possible. RCOG recommends that the placenta should be at least 2 cm away from internal os for an attempted vaginal delivery. When a vaginal delivery is attempted, consultant obstetrician and anesthetists are present in delivery suite. In cases of fetal distress and major degrees (traditional grade III and IV) a caesarean section is indicated. Caesarian section is contraindicated in cases of disseminated intravascular coagulation. An obstetrician may need to divide the anterior lying placenta. In such cases, blood loss is expected to be high and thus blood and blood products are always kept ready. In rare cases, hysterectomy may be required.