From the Guidelines
The protocol for vaginal bleeding in the first trimester should begin with a thorough assessment using transvaginal and transabdominal ultrasound, as well as serum hCG measurement, to determine the cause and severity of the bleeding. This approach is supported by the American College of Radiology Appropriateness Criteria 1, which recommend the use of ultrasound as the primary imaging modality in the evaluation of first trimester vaginal bleeding.
Key Diagnostic Steps
- A pelvic examination to assess for any visible bleeding or cervical dilation
- Transvaginal ultrasound to evaluate the uterus and adnexa for any signs of pregnancy or other pathology
- Serum hCG measurement to confirm pregnancy and assess for any abnormalities
- Quantification of bleeding and assessment of vital sign stability
Management Options
- For threatened abortion with a viable intrauterine pregnancy, management is typically expectant with pelvic rest and follow-up
- For incomplete abortion, options include expectant management, medical management with misoprostol, or surgical evacuation
- For ectopic pregnancy, treatment depends on stability and may include methotrexate or surgical intervention
- Rh-negative women should receive Rh immunoglobulin (RhoGAM) 50 mcg if less than 12 weeks gestation
Follow-up and Support
- Patients should be advised to return immediately for heavy bleeding, severe pain, fever, or dizziness
- Close follow-up is necessary to ensure resolution of symptoms and to provide emotional support, as bleeding can cause significant anxiety even when the pregnancy remains viable. According to 1, pulsed methods of Doppler US should generally be avoided in the first trimester when there is a normal, or a potentially normal, IUP.
From the Research
Protocol for Vaginal Bleeding in First Trimester
The protocol for vaginal bleeding in the first trimester involves several steps, including:
- Evaluation of the patient's symptoms and medical history 2, 3, 4
- Performance of transvaginal ultrasonography to detect fetal heart sounds and assess the gestational sac 3, 4
- Measurement of beta subunit of human chorionic gonadotropin (β-hCG) levels to distinguish between normal and abnormal early pregnancy 3, 4
- Assessment for signs of ectopic pregnancy, such as adnexal mass or free pelvic fluid 3, 4
Differential Diagnoses
The differential diagnoses for vaginal bleeding in the first trimester include:
- Spontaneous abortion 2, 3, 4
- Ectopic pregnancy 2, 3, 4
- Gestational trophoblastic disease 2, 3
- Subchorionic hemorrhage 3
- Embryonic demise 3
- Anembryonic pregnancy 3
- Incomplete abortion 3
Treatment Options
Treatment options for vaginal bleeding in the first trimester depend on the underlying cause and may include:
- Expectant management 3, 4, 5
- Medical management with misoprostol or methotrexate 3, 4
- Surgical intervention 3, 4
- Vaginal micronized progesterone to prevent miscarriage in women with a history of recurrent miscarriage or threatened miscarriage 6, 5
Progesterone Supplementation
Progesterone supplementation with vaginal micronized progesterone 400 mg twice daily may be beneficial for women with a history of miscarriage and current pregnancy bleeding, particularly those with three or more previous miscarriages 6, 5.