How ectopic pregnancy is tested on Step 1
Risk factors damage tubal cilia and transport.
Treatment
Choose by stability and size.
Early pregnancy loss
The cervix and products of conception define the type.
| Type | Cervical os | Products of conception | Key feature |
|---|---|---|---|
| Threatened | Closed | All retained | Bleeding with a viable pregnancy |
| Inevitable | Open | Still in uterus | Loss cannot be prevented |
| Incomplete | Open | Some passed, some retained | Ongoing bleeding and cramping |
| Complete | Closed | All passed | Bleeding and pain settle |
| Missed | Closed | Retained nonviable pregnancy | No symptoms or mild spotting |
Most first-trimester losses are caused by chromosomal abnormalities, most often trisomies.
Differential diagnosis
Other causes of pelvic pain in early pregnancy.
- Ovarian torsion: sudden one-sided pain with nausea; enlarged ovary with reduced flow on Doppler.
- Ruptured corpus luteum cyst: pain and free fluid with an intrauterine pregnancy.
- Appendicitis: periumbilical pain moving to the right lower quadrant, fever.
- Molar pregnancy: very high hCG and a "snowstorm" uterus.
Worked example
Combine hCG and ultrasound.
functions Worked example — pain at 7 weeks
A 29-year-old with a history of chlamydia has 7 weeks of amenorrhea, left lower abdominal pain, and spotting. Vital signs are normal. Serum β-hCG is 2,800 mIU/mL. Transvaginal ultrasound shows an empty uterus and a small left adnexal mass without fetal cardiac activity. What is the diagnosis and the best treatment?
- Prior chlamydia damages tubal cilia and raises ectopic risk.
- At this hCG level, an intrauterine pregnancy is usually visible on transvaginal ultrasound; the uterus is empty.
- The adnexal mass is the likely ectopic pregnancy.
- The patient is stable with a small unruptured mass and no heartbeat, so methotrexate is appropriate with serial hCG follow-up.
Answer. Tubal ectopic pregnancy; treat with methotrexate (and Rh immune globulin if Rh-negative).