From the Guidelines
For a pregnant woman at 8 weeks with spotting, a thorough evaluation is essential, starting with a detailed history, physical examination, and transvaginal ultrasound to confirm intrauterine pregnancy and rule out ectopic pregnancy, as recommended by the American College of Radiology Appropriateness Criteria 1. The evaluation should include:
- A detailed history including the amount of bleeding, associated pain, and risk factors for miscarriage
- A physical examination focusing on vital signs, abdominal examination, and a speculum exam to visualize the cervix
- Laboratory tests, such as quantitative beta-hCG levels, complete blood count, blood type and Rh status, and possibly progesterone levels
- Transvaginal ultrasound, which is the primary imaging modality in the evaluation of patients presenting with vaginal bleeding in the first trimester of pregnancy, to confirm intrauterine pregnancy, assess fetal viability, and rule out ectopic pregnancy 1 If the pregnancy is viable with a closed cervix, provide reassurance as spotting can be normal in early pregnancy, and recommend pelvic rest (no intercourse or tampons) until bleeding resolves. If Rh-negative, administer RhoGAM 50 mcg IM. Follow up with serial beta-hCG measurements every 48-72 hours to ensure appropriate doubling, and repeat ultrasound in 1-2 weeks to confirm ongoing viability. This comprehensive approach is necessary because spotting may indicate threatened abortion, ectopic pregnancy, or other complications requiring prompt intervention, though approximately 50% of women with first-trimester bleeding continue with viable pregnancies. It is also important to guard against injury to normal pregnancies due to inappropriate treatment with methotrexate or surgical intervention 1.
From the Research
Diagnostic Approach
When working up a female who is eight weeks pregnant with spotting, the following steps can be taken:
- Obtain a thorough medical history and perform a physical examination to identify any signs of ectopic pregnancy or other complications 2.
- Perform a pregnancy test using a sensitive beta hCG qualitative test to confirm pregnancy 2.
- If the patient is stable, perform sonography, first transabdominally and then transvaginally, to evaluate for intrauterine pregnancy 2.
- If the patient is unstable, provide immediate resuscitation and consult with a gynecologist; invasive diagnostic methods may be necessary 2.
Laboratory Tests
The following laboratory tests can be used to aid in diagnosis:
- Quantitative beta hCG measurements to evaluate for ectopic pregnancy 3.
- Progesterone assays to evaluate for ectopic pregnancy 2.
- Serial beta hCG measurements to evaluate for changes in hCG levels over time 4.
Imaging Studies
The following imaging studies can be used to aid in diagnosis:
- Transvaginal ultrasound to evaluate for intrauterine pregnancy and ectopic pregnancy [(2,5)].
- Doppler ultrasound to evaluate for blood flow to the pregnancy 2.
Special Considerations
In cases where the patient has a molar pregnancy, qualitative beta-hCG urine assays may be misleading due to markedly elevated hCG levels 6. In cases where the patient has indeterminate transvaginal ultrasound findings, the rate of change of serial beta-hCG values can be used to predict ectopic pregnancy 4.