Bleeding in Pregnancy / Placenta Previa / Placental Abruption
Bleeding in Pregnancy /
Placenta Previa / Placental Abruption
Bleeding may occur at various times in pregnancy. Although
bleeding is alarming, it may or may not be a serious complication. The time of
bleeding in the pregnancy, the amount, and whether or not there is pain may
vary depending on the cause.
Bleeding in the first trimester
of pregnancy is quite common and may be due to the following:
- miscarriage (pregnancy loss)
- ectopic pregnancy (pregnancy in the fallopian tube)
- gestational trophoblastic disease (a
rare condition that may be cancerous in which a grape-like mass of fetal
and placental tissues develops)
- implantation of the placenta in the uterus
- infection
Bleeding in late pregnancy
(after about 20 weeks) may be due to the following:
- placenta
previa
(placenta is near or covers the cervical opening)
- placental
abruption
(placenta detaches prematurely from the uterus)
- unknown
cause
What is placenta previa?
Placenta previa is a
condition in which the placenta is attached close to or covering the cervix (opening of the uterus). Placenta previa occurs in about one in
every 200 live births. There are three types of placenta previa:
- total
placenta previa - the placenta completely covers the cervix.
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- partial
placenta previa - the placenta is partially over the cervix.
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- marginal
placenta previa - the placenta is near the edge of the cervix.
What causes placenta
previa?
The cause of placenta previa is unknown, but it is associated with
certain conditions including the following:
- women who have scarring of the uterine wall from
previous pregnancies
- women who have fibroids or other abnormalities of the
uterus
- women who have had previous uterine surgeries or
cesarean deliveries
- older
mothers
(over age 35)
- African-American or other minority
race mothers
- cigarette
smoking
- placenta
previa in a previous pregnancy
Why is placenta previa a
concern?
The greatest risk of placenta previa is bleeding (or hemorrhage). Bleeding often
occurs as the lower part of the uterus thins during the third trimester of
pregnancy in preparation for labor. This causes the area of the placenta over
the cervix to bleed. The more of the placenta that covers the cervical os, the
greater the risk for bleeding. Other risks include the following:
- abnormal
implantation of the placenta
- slowed
fetal growth
- preterm
birth
- birth
defects
- infection
after delivery
What are the symptoms of
placenta previa?
The most common symptom of placenta previa is vaginal bleeding that is bright red and not associated with abdominal
tenderness or pain, especially in the third trimester of pregnancy.
However, each woman may exhibit different symptoms of the condition or symptoms
may resemble other conditions or medical problems. Always consult your
physician for a diagnosis.
How is placenta previa
diagnosed?
In addition to a complete medical history and physical examination, an ultrasound (a test using sound waves to
create a picture of internal structures) may be used to diagnose placenta
previa. An ultrasound can show the location of the placenta and how much is
covering the cervix. A vaginal ultrasound may be more accurate in diagnosis.
Although ultrasound may show a low-lying placenta in early
pregnancy, only a few women will develop true placenta previa. It is common for the placenta to
move upwards and away from the cervix as the uterus grows, called placental
migration
.
Treatment for placenta
previa:
Specific treatment for placenta previa will be determined by your
physician based on:
- your pregnancy, overall health, and
medical history
- extent of the condition
- your tolerance for specific
medications, procedures, or therapies
- expectations for the course of the
condition
- your opinion or preference
There is no treatment to change the position of the placenta. Once
placenta previa is diagnosed, additional ultrasound examinations are often
performed to track its location. It may be necessary to deliver the baby,
depending on the amount of bleeding, the gestational age, and condition of the
fetus. Cesarean delivery is necessary for most cases of placenta previa. Severe
blood loss may require a blood transfusion.
What is placental
abruption?
Placental abruption is the
premature separation of a placenta from its implantation in the uterus. Within the placenta are many blood vessels that allow the
transfer of nutrients to the fetus from the mother. If the placenta begins to
detach during pregnancy, there is bleeding from these vessels. The larger the
area that detaches, the greater the amount of bleeding. Placental abruption
occurs about once in every 120 births. It is also called abruptio placenta.
What causes placental
abruption?
Other than direct
trauma to the uterus such as in a motor vehicle accident, the cause of
placental abruption is unknown. It is, however, associated with certain
conditions, including the following:
- previous
pregnancy with placental abruption
- hypertension
(high blood pressure)
- cigarette
smoking
- multiple
pregnancy
Why is placental
abruption a concern?
Placental abruption is dangerous because of the risk of
uncontrolled bleeding (hemorrhage). Although severe placental abruption is
rare, other complications may include the following:
- hemorrhage
and shock
- disseminated
vascular coagulation (DIC) - a serious blood clotting
complication.
- poor
blood flow and damage to kidneys or brain
- stillbirth
- postpartum
(after delivery) hemorrhage
What are the symptoms of
placental abruption?
The most common symptom of placental abruption is dark red vaginal bleeding
with pain during the third trimester of pregnancy. It also can occur during labor.
However, each woman may experience symptoms differently. Symptoms may include:
- vaginal
bleeding
- abdominal
pain
- uterine
contractions that do not relax
- blood
in amniotic fluid
- nausea
- thirst
- faint
feeling
- decreased
fetal movements
The symptoms of placental abruption may resemble other medical
conditions. Always consult your physician for a diagnosis.
How is placental
abruption diagnosed?
The diagnosis of placental abruption is usually made by the symptoms, and the amount of bleeding and pain.
Ultrasound may also
be used to show the location of the bleeding and to check the fetus. There are three grades of placental
abruption, including the following:
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- Grade 1 - small
amount of vaginal bleeding and some uterine contractions, no signs of
fetal distress or low blood pressure in the mother.
- Grade 2 - mild
to moderate amount of bleeding, uterine contractions, the fetal heart rate
may shows signs of distress.
- Grade 3 - moderate
to severe bleeding or concealed (hidden) bleeding, uterine contractions
that do not relax (called tetany), abdominal pain, low blood pressure,
fetal death.
Sometimes placental abruption is not diagnosed until after
delivery, when an area of clotted blood is found behind the placenta.
Treatment for placental
abruption:
Specific treatment for placental abruption will be determined by
your physician based on:
- your pregnancy, overall health, and
medical history
- extent of the disease
- tolerance for specific medications,
procedures, or therapies
- expectations for the course of the
disease
- your opinion or preference
There is no treatment to stop placental abruption or reattach the
placenta. Once placental abruption is diagnosed, a woman's care depends on the
amount of bleeding, the gestational age, and condition of the fetus. Cesarean
delivery is performed for most cases of placental abruption and emergency
delivery may be needed if hemorrhage occurs. Severe blood loss may require a
blood transfusion
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