During the first 20 weeks of pregnancy, 20 to 30% of women have vaginal bleeding. For many of these women, there is a problem with the pregnancy, but some women have light bleeding or spotting and have a normal, healthy pregnancy. In about half of women with bleeding, the pregnancy ends in a miscarriage. If miscarriage does not occur immediately, problems later in the pregnancy are possible. For example, the baby's birth weight may be low, the pregnancy may result in a stillbirth (death of a fetus after 20 weeks of pregnancy), or the baby may be born early (preterm birth) or die during or shortly after birth. If there is heavy bleeding, blood pressure may become dangerously low, resulting in shock. However, many women with light bleeding in early pregnancy go on to have a healthy pregnancy and delivery.
The amount of bleeding can range from spots of blood to heavy bleeding. Passing large amounts of blood is always a concern, but spotting or mild bleeding may also indicate a serious disorder. Women with any vaginal bleeding should contact their doctor.
Causes of Vaginal Bleeding in Early Pregnancy
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 of vaginal bleeding during early pregnancy is
A miscarriage (also called spontaneous abortion)
Vaginal bleeding may mean that a miscarriage is possible, but sometimes the bleeding stops and the pregnancy continues without any problems. When a miscarriage does occur, it usually happens in a few stages. First, there is bleeding. Then cramping develops, which may be severe and the bleeding may become heavy. The woman then usually passes the pregnancy, and she may see pregnancy tissue pass out of the vagina.
Sometimes, a miscarriage does not cause any symptoms and is found when the fetus is assessed during a regular medical visit (called a missed abortion). If a woman suspects she is having a miscarriage, she should contact her doctor. Sometimes women can go through a miscarriage at home, but if the pain or bleeding is severe, or if the pregnancy tissue is not passed completely, they need treatment with medications or a procedure to make sure they are safe and the pregnancy passes completely.
The contents of the uterus may be infected before, during, or after the miscarriage (called a septic abortion).
The most dangerous cause of vaginal bleeding during early pregnancy is
An abnormally located pregnancy (ectopic pregnancy)—one that is not in its usual place in the uterus—for example, one that is in a fallopian tube
An ectopic pregnancy is life threatening. A pregnancy implanted outside the uterus will not develop normally. As the pregnancy grows in a fallopian tube or other body part (such as the ovary, cervix, old cesarean scar in the uterus, or abdomen), it may cause that part to burst. This leads to severe pain and heavy bleeding, which can result in severe harm or even death to the pregnant woman. When an ectopic pregnancy is diagnosed, the treatment is to end the pregnancy with medications or remove it with surgery.
Another possibly dangerous but less common cause is rupture of a corpus luteum cyst. After an egg is released from the ovary, the structure that released it (the corpus luteum) may fill with fluid or blood instead of breaking down and disappearing as it usually does.
Risk factors
For miscarriage, risk factors include the following:
Age over 35
One or more miscarriages in previous pregnancies
Use of illicit drugs, such as , or possibly other substances, such as alcohol
Abnormalities in the uterus, such as fibroids, scarring, or an abnormal shape of the uterus
For ectopic pregnancy, risk factors include
A previous ectopic pregnancy (the most important risk factor)
Previous abdominal surgery, especially for permanent sterilization (tubal ligation)
Fallopian tube abnormalities
Current use of an intrauterine device (IUD)
In vitro fertilization to conceive the current pregnancy
Additional risk factors for ectopic pregnancy include history of sexually transmitted infection or pelvic inflammatory disease, current use of estrogen/progestin oral contraceptives, cigarette smoking, infertility, and prior miscarriage or abortion.
Evaluation of Vaginal Bleeding in Early Pregnancy
Doctors first determine whether the cause of vaginal bleeding is an ectopic pregnancy.
Warning signs
In pregnant women with vaginal bleeding during early pregnancy, the following symptoms are cause for concern:
Fainting, light-headedness, or a rapid heart rate—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
When to see a doctor
Women with warning signs should see a doctor immediately.
Women without warning signs should see a doctor within 48 to 72 hours.
What the doctor does
Doctors ask about the symptoms and medical history (including past pregnancies, miscarriages, abortions, and risk factors for ectopic pregnancy and miscarriage). 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:
How severe it is (for example, how many pads are used or soaked in an hour)
Whether clots or tissue were passed
Whether pain accompanies the bleeding
If the woman has pain in addition to vaginal bleeding, 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 rapid heart rate 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), which may allow the pregnancy 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.
Testing
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 a home pregnancy test indicates pregnancy but pregnancy has not been confirmed by a health care practitioner, doctors do a pregnancy test using a urine sample.
Once pregnancy is confirmed, several tests are done:
Blood type and Rh status (positive or negative)
Usually ultrasonography
Usually blood tests to measure a hormone (human chorionic gonadotropin, or hCG) produced by the placenta during early pregnancy
Rh status is determined because a pregnant woman with Rh-negative blood must be treated with Rho(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) or other tests to check if there is problem with the ability of the blood to clot normally or in case a blood transfusion is needed.
Typically, ultrasonography is done using an ultrasound device inserted into the vagina. 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, a miscarriage is diagnosed. If a heartbeat is detected, miscarriage is much less likely but may still occur.
Ultrasonography can also help identify the following:
Any parts of the placenta or other pregnancy-related tissues that remain in the uterus even after a miscarriage
Sometimes an ectopic pregnancy, depending on where it is located and how big it is
An abnormal pregnancy, such as a molar pregnancy
Measuring hCG levels helps doctors interpret ultrasonography results and distinguish a normal pregnancy from an ectopic pregnancy. If there is a concern that a woman has an ectopic pregnancy, hCG levels are measured frequently and ultrasonography is repeated as needed.
A ruptured ectopic pregnancy is an emergency. If the likelihood of a ruptured ectopic pregnancy is moderate or high,doctors may need to do surgery. In life-threatening situations, they may need to do emergency surgery even before they do blood tests or ultrasonography. Usually, they 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. Sometimes they make a large incision in the lower part of the abdomen (laparotomy).
Treatment of Vaginal Bleeding in Early Pregnancy
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.
If the bleeding is heavy, 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. Surgery is done immediately when an ectopic pregnancy has ruptured
When bleeding results from a specific disorder, that disorder is treated, if possible.
Key Points
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 rapid heart rate, 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 Rho(D) immune globulin to prevent her from producing antibodies that may attack the fetus's red blood cells in subsequent pregnancies.
