Early pregnancyFree in the app
Miscarriage — diagnosis
Transvaginal scan criteria before calling a pregnancy non-viable.
Source: NICE NG126 (2026)TVS findings
| CRL <7 mm, no heartbeat | Rescan at least 7 days later. |
|---|---|
| CRL ≥7 mm, no heartbeat | Second opinion and/or rescan ≥7 days later before diagnosing. |
| MSD <25 mm, no fetal pole | Rescan at least 7 days later. |
| MSD ≥25 mm, no fetal pole | Second opinion and/or rescan ≥7 days later. |
| Transabdominal scan only | Record CRL/MSD; rescan at least 14 days later. |
Types
| Threatened | Bleeding, os closed, viable pregnancy. |
|---|---|
| Inevitable | Bleeding with open os. |
| Incomplete | Some tissue passed; retained products on scan. |
| Complete | All tissue passed; empty uterus, os closed. |
| Missed | Non-viable pregnancy, nothing passed yet. |
Threatened miscarriage with a previous miscarriage: vaginal micronised progesterone 400 mg twice daily to 16 completed weeks once heartbeat seen.
A summary for trained clinicians. Always check the full guideline, the patient in front of you and your hospital's protocol. Spotted an error? Tell us.