Vaginal Bleeding During Early Pregnancy
During the first 20 weeks of pregnancy, 20 to 30% of women have vaginal bleeding. In about half of these women, the pregnancy ends in a miscarriage. If miscarriage does not occur immediately, problems later in the pregnancy are more likely. For example, the baby's birth weight may be low, or the baby may be born early (preterm birth), be born dead (stillbirth), or die during or shortly after birth. If bleeding is profuse, blood pressure may become dangerously low, resulting in shock.
The amount of bleeding can range from spots of blood to a massive amount. Passing large amounts of blood is always a concern, but spotting or mild bleeding may also indicate a serious disorder.
Vaginal bleeding during early pregnancy may result from disorders related to the pregnancy (obstetric) or not (see Table: Some Causes and Features of Vaginal Bleeding During Early Pregnancy).
The most common cause is
There are different degrees of miscarriage (also called spontaneous abortion—see Miscarriage). A miscarriage may be possible (threatened abortion) or certain to occur (inevitable abortion). All of the contents of the uterus (fetus and placenta) may be expelled (complete abortion) or not (incomplete abortion). The contents of the uterus may be infected before, during, or after the miscarriage (septic abortion). The fetus may die in the uterus and remain there (missed abortion). Any type of miscarriage can cause vaginal bleeding during early pregnancy.
The most dangerous cause of vaginal bleeding is
Another possibly dangerous but less common cause is rupture of a corpus luteum cyst. After an egg is released, the structure that released it (the corpus luteum) may fill with fluid or blood instead of breaking down and disappearing as it usually does. If an ectopic pregnancy or a corpus luteum cyst ruptures, bleeding may be profuse, leading to shock.
Doctors first determine whether the cause is an ectopic pregnancy.
In pregnant women with vaginal bleeding during early pregnancy, the following symptoms are cause for concern:
Fainting, light-headedness, or a racing heart—symptoms that suggest very low blood pressure
Loss of large amounts of blood or blood that contains tissue or large clots
Severe abdominal pain that worsens when the woman moves or changes positions
Fever, chills, and a vaginal discharge that contains pus mixed with the blood
Doctors ask about the symptoms and medical history (including past pregnancies, miscarriages, and abortions). Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause and the tests that may need to be done (see Table: Some Causes and Features of Vaginal Bleeding During Early Pregnancy ).
Doctors ask about the bleeding:
If pain is present, doctors ask when and how it started, where it occurs, how long it lasts, whether it is sharp or dull, and whether it is constant or comes and goes.
During the physical examination, doctors first check for fever and signs of substantial blood loss, such as a racing heart and low blood pressure. They then do a pelvic examination, checking to see whether the cervix (the lower part of the uterus) has started to open (dilate) to enable the fetus to pass through. If any tissue (possibly from a miscarriage) is detected, it is removed and sent to a laboratory to be analyzed.
Doctors also gently press on the abdomen to see whether it is tender when touched.
Some Causes and Features of Vaginal Bleeding During Early Pregnancy
During the examination, doctors may use a handheld Doppler ultrasound device, placed on the woman's abdomen, to check for a heartbeat in the fetus.
If pregnancy has not been confirmed by a health care practitioner, a pregnancy test using a urine sample is done. Once pregnancy is confirmed, several tests are done:
Rh status is determined because a pregnant woman with Rh-negative blood must be treated with Rh0(D) immune globulin if she has any vaginal bleeding. Treatment is needed to prevent her from producing antibodies that may attack the fetus's red blood cells in subsequent pregnancies (see Rh Incompatibility). If bleeding is substantial (more than about a cup), doctors also do a complete blood cell count (CBC) and tests to check for abnormal antibodies or to cross-match blood (to determine whether the woman’s blood type is compatible with a donor’s). If blood loss is substantial or shock develops, tests are done to determine whether blood can clot normally.
Typically, ultrasonography is done using an ultrasound device inserted into the vagina unless the examination indicated that a complete miscarriage occurred. Ultrasonography can detect a pregnancy in the uterus and can detect a heartbeat after about 6 weeks of pregnancy. If no heartbeat is detected after this time, miscarriage is inevitable. If a heartbeat is detected, miscarriage is much less likely but may still occur. Ultrasonography can also help identify a miscarriage that is incomplete, is infected, or has been missed. It can detect any parts of the placenta or other pregnancy-related tissues that remain in the uterus. Ultrasonography can help identify a ruptured corpus luteum cyst and a hydatidiform mole or other forms of gestational trophoblastic disease. Sometimes ultrasonography can detect an ectopic pregnancy, depending on where it is located and how big it is.
Measuring hCG levels helps doctors interpret ultrasonography results and distinguish a normal pregnancy from an ectopic pregnancy. If the likelihood of an ectopic pregnancy is low, hCG levels are measured periodically. If the likelihood is moderate or high, doctors may make a small incision just below the navel and insert a viewing tube (laparoscope) to directly view the uterus and surrounding structures (laparoscopy) and thus determine whether an ectopic pregnancy is present.
If bleeding is profuse, if shock develops, or if a ruptured ectopic pregnancy is likely, one of the first things doctors do is to place a large catheter in a vein so that blood can be quickly given intravenously.
When bleeding results from a disorder, that disorder is treated if possible. For example, surgery is done when an ectopic pregnancy has ruptured.
Although doctors have typically recommended bed rest when a miscarriage seems possible, there is no evidence that bed rest helps prevent miscarriage. Refraining from sexual intercourse is advised, although intercourse has not been definitely connected with miscarriages.
The most common cause of bleeding during early pregnancy is a miscarriage.
The most serious cause of vaginal bleeding is an ectopic pregnancy.
A pregnant woman should see a doctor immediately if she has a racing heart, faints, or feels faint.
Blood tests to determine whether blood is Rh-negative or Rh-positive are done because if a pregnant woman with Rh-negative blood has vaginal bleeding, she must be given Rh0(D) immune globulin to prevent her from producing antibodies that may attack the fetus's red blood cells in subsequent pregnancies.