First trimester abortion
See Vaginal bleeding in pregnancy (less than 20wks) for diagnostic approach to early vaginal bleeding in pregnancy.
Background
- Estimates are up to 15% of pregnancies end in a 1st trimester abortion, usually due to fetal chromosomal abnormalities
Abortion Types
Classification | Characteristics | OS | Fetal Tissue Passage | Misc |
---|---|---|---|---|
Threatened | Abdominal pain or bleeding; < 20 weeks gestation | Closed | No | If < 11 weeks (with fetal cardiac activity) 90% progress to term. If between 11 and 20 weeks 50% progress to term |
Inevitable | Abdominal pain or bleeding; < 20 weeks gestation | Open | No | |
Incomplete | Abdominal pain or bleeding; < 20 weeks gestation | Open | Yes, some | |
Complete | Abdominal pain or bleeding; < 20 weeks gestation | Closed | Yes, complete expulsion of products | Distinguish from ectopic based on decreasing hCG and/or decreased bleeding |
Missed | Fetal death at <20 weeks without passage of any fetal tissue for 4 weeks after fetal death | Closed | No | |
Septic | Infection of the uterus during a miscarriage. Most commonly caused by retained products of conception | Open | No, or may be incomplete | Uterine tenderness and purulent discharge from the OS may be present |
Clinical Features
- Visualize any clots or bleeding from external os
- Assess internal os as open or closed based on ability to pass finger through os
- Pregnancy ≤ 13 weeks
Differential Diagnosis
Vaginal Bleeding in Pregnancy (<20wks)
- Ectopic pregnancy
- Subchorionic hematoma
- First Trimester Abortion
- Complete Abortion
- Incomplete Abortion
- Inevitable Abortion
- Missed Abortion
- Septic abortion
- Threatened Abortion
- Gestational trophoblastic disease
- Consider when pregnancy-induced hypertension is seen before 24 wks of gestation
- Heterotopic pregnancy
- Implantation bleeding
- Molar pregnancy
- Non-pregnancy related bleeding
- Cervicitis
- Fibroids
- Implantation bleeding
Evaluation
Workup
- Pelvic or Trans-abdominal ultrasound to assess fetal dating and heart rate
- Type and Screen/ABO
- Hemoglobin
Evaluation
Management
- RhoGam if Rh Negative
- IVF and/or PRBCs if severe bleeding
- Misoprostol only for < 12 weeks gestation: give 800mcg vaginally, dose can be repeated once within 7 days if no response [1]
- If available, mifepristone 200mg PO should be given 24 hours prior to first dose of misoprostol (NNT = 6)
- Supportive care with anti-emetic and NSAIDs for misoprostol side effects
- D&C and OB/gyn consult may be necessary if medical management fails or continuous products/vaginal bleeding > 7-14 days
Disposition
- Discharge with close OB follow-up for repeat ultrasound
- Urgent OBGYN consult if active hemorrhage and need for Dilation and Curretage
See Also
References
- ↑ ACOG Practice Bulletin Update. Early Pregnancy Loss. November 2018. https://www.acog.org/-/media/Practice-Bulletins/Committee-on-Practice-Bulletins----Gynecology/Public/pb200.pdf?dmc=1&ts=20181207T1637252429