Gestational context
Trimester 1
booking
12w
anatomy
24w
28w
36w
term
Ultrasound criteria (definitive)
- Crown-rump length 7 mm or more with no cardiac activity.
- Mean sac diameter 25 mm or more with no embryo.
- No embryo with a heartbeat 2 weeks or more after a scan that showed a sac without a yolk sac, or 11 days or more after a scan that showed a sac with a yolk sac.
- Anything less is suspicious, not diagnostic: repeat in 7 to 14 days. The cost of a false diagnosis is a wanted pregnancy ended.
Anembryonic pregnancy (early pregnancy loss)
Transvaginal, 7+5 weeks by sac size. Gestational sac with a mean diameter of 28 mm.
Open in the Ultrasound LabEarly intrauterine pregnancy with a 3 mm embryo
Transvaginal, About 5 to 6 weeks (embryo 3 mm). An intrauterine sac.
Open in the Ultrasound LabIncomplete miscarriage with retained products in the cervical region
Transabdominal, sagittal, 15 weeks. Fundus and body of the uterus empty.
Open in the Ultrasound LabThe clinical vocabulary
| Term | Meaning |
|---|---|
| Threatened | Bleeding with a closed cervix and a live pregnancy; most continue |
| Inevitable | Bleeding with an open cervix |
| Incomplete | Some tissue passed, some retained; open cervix, bleeding |
| Complete | All tissue passed; empty uterus, bleeding settling |
| Missed (delayed) | A non-viable pregnancy retained without symptoms |
| Septic | Any of the above with infection; antibiotics and evacuation |
Management: three options
- Anti-D for Rh-negative patients (practice varies for very early loss; follow local guidance).
- Pain relief, a plan for bleeding that is too heavy, a follow-up test or scan, and the offer of support. The loss is grieved; say so.
- Recurrent loss (two or three or more) prompts investigation: antiphospholipid antibodies, parental karyotypes, uterine anatomy, thyroid.
| Expectant | Medical | Surgical |
|---|---|---|
| Wait up to 2 to 4 weeks; most complete | Misoprostol (with mifepristone pre-treatment where available, which improves success) | Suction aspiration under local or general anaesthesia |
| Avoid with heavy bleeding, infection or a large retained sac | Success 80 to 90 percent; heavy bleeding and cramping expected; a repeat dose if needed | Fastest and most certain; small risks of infection, perforation, adhesions |
On the modelEndometriumCervixBody and myometrium