Early pregnancy bleeding


Early pregnancy bleeding refers to vaginal bleeding before 24 weeks of gestational age. If the bleeding is significant, hemorrhagic shock may occur. Concern for shock is increased in those who have loss of consciousness, chest pain, shortness of breath, or shoulder pain.
Common causes of early pregnancy bleeding include ectopic pregnancy, threatened miscarriage, and pregnancy loss. Most miscarriages occur before 12 weeks gestation age. Other causes include implantation bleeding, gestational trophoblastic disease, polyps, and cervical cancer. Tests to determine the underlying cause usually include a speculum examination, ultrasound, and hCG.
Treatment depends on the underlying cause. If tissue is seen at the cervical opening it should be removed. In those in who the pregnancy is in the uterus and who have fetal heart sounds, watchful waiting is generally appropriate. Anti-D immune globulin is usually recommended in those who are Rh-negative. Occasionally surgery is required.
About 30% of women have bleeding in the first trimester. Bleeding in the second trimester is less common. About 15% of women who realize they are pregnant have a miscarriage. Ectopic pregnancy occurs in under 2% of pregnancies.

Differential diagnosis

The differential diagnosis depends on whether the bleeding occurs in the first trimester or in the second/third trimesters.
Obstetric causes of first trimester bleeding include the following:
Obstetric causes of second/third trimester bleeding include the following:
Other causes of early pregnancy bleeding include the following:
Early pregnancy bleeding is usually from a maternal source, rather than a fetal, one. The maternal source may be a disruption in the vessels of the decidua or a lesion in the cervix or vagina. Vasa praevia is a rare condition that can result in bleeding from the fetoplacental circulation.

Diagnostic approach

The initial evaluation of early pregnancy bleeding involves a history and physical examination. The relevant history includes determining the gestational age of fetus and characterizing the bleeding. Bleeding that is at least as heavy as menstrual bleeding or associated with clots, tissue, lightheadedness, or pelvic discomfort is associated with increased risks of ectopic pregnancy and spontaneous abortion. Discomfort in the middle of the abdomen is more closely associated with spontaneous abortion; discomfort on a side of the abdomen is more closely associated with ectopic pregnancy. Risk factors for ectopic pregnancy or spontaneous abortion should also be considered.
The physical examination includes assessing vital signs and performing an abdominal and pelvic examination. Signs of hemodynamic instability or peritonitis require emergent intervention. A pelvic examination may reveal non-obstetric causes of bleeding such as bleeding from the vagina or cervix. It may also show visible products of conception suggestive of an incomplete abortion.
If the person is stable and a pelvic exam is unrevealing, ultrasonography and/or serial measurement of hCG is generally recommended to assess fetal location and viability. Before 10 weeks gestation, a slower than normal increase in hCG suggests early pregnancy loss or ectopic pregnancy. By approximately 10 weeks, hCG plateaus and ultrasound is preferred to determine the location of the pregnancy. In the presence of prior pelvic imaging, fetal heart tracing with Doppler sonography is sufficient to assess fetal viability beginning at 10–12 weeks of gestation. Bleeding associated with an intrauterine, viable pregnancy suggests threatened early pregnancy loss. Bleeding associated with an intrauterine, nonviable pregnancy suggests early pregnancy loss. If the viability of an intrauterine pregnancy is uncertain, repeat ultrasonography coupled with laboratory measurement of progesterone and/or serial hCG can be helpful. The absence of either intrauterine or ectopic pregnancy on imaging is suggestive of a complete early pregnancy loss or a pregnancy of unknown location.

Management

The management of early pregnancy bleeding depends on its severity and cause. People with significant blood loss who become hemodynamically unstable require rapid intervention. Laboratory studies that may be helpful include hemoglobin/hematocrit, coagulation studies, and type and crossmatch. Regardless of hemodynamic stability, a red blood cell antibody screen is usually checked. Patients who are Rh-negative are usually given anti-D immune globulin to prevent RhD isoimmunization. The fetal heart rate can also be checked to assess the need for delivery.
Ectopic pregnancy is treated with methotrexate therapy or surgery. Surgery is required for patients who have failed or have contraindications to methotrexate therapy, are experiencing significant blood loss, or have signs of ectopic rupture. Threatened early pregnancy loss is often treated with watchful waiting. Bed rest and progesterone therapy have not been shown to increase the likelihood of a viable outcome. Early pregnancy loss can be treated with watchful waiting, medication, or uterine aspiration based on shared decision-making between the patient and provider.

Epidemiology

First trimester bleeding is more common than second or third trimester bleeding. First trimester bleeding may be associated with smaller estimated fetal weight late in pregnancy.