1. UOG Journal Club: November 2011 Ultrasound prediction of miscarriage
Accuracy of first-trimester ultrasound in the diagnosis of early embryonic demise: a systematic review Y. Jeve, R. Rana, A. Bhide, S. Thangaratinam
Limitations of current definitions of miscarriage using mean gestational sac diameter and crown–rump length measurements: a multicenter observational study
Y. Abdallah, A. Daemen, E. Kirk et al.
Gestational sac and embryonic growth are not useful as criteria to define miscarriage: a multicenter observational study
Y. Abdallah, A. Daemen, S. Guha et al.
Clinical implications of intra- and interobserver reproducibility of transvaginal sonographic measurements of gestational sac and crown–rump length at 6–9 weeks gestation
Pexsters, J. Luts, D. Van Schoubroeck et al.
Volume 38, Issue 5, Date: November 2011, pages 489–515 (all articles)
Journal Club slides prepared by Dr Tommaso Bignardi
(UOG Editor for Trainees)

2. Diagnosis of miscarriage on TVS
Royal College of Obstetricians and Gynaecologists
(RCOG) 2006
CRL ≥ 6mm with no visible cardiac activity
MSD ≥ 20mm without a visible embryo or yolk sac
American College of Radiologists (ACR) 2000
CRL > 5mm with no visible cardiac activity
MSD > 16mm without a visible embryo or yolk sac
Society of Obstetricians and Gynaecologists of Canada
(SOGC) 2005
CRL > 5mm with no visible cardiac activity
MSD > 8mm without a visible yolk sac
MSD > 16mm without a visible embryo
CRL, crown–rump length
MSD, mean sac diameter

3. The current criteria used to diagnose miscarriage at ultrasound show variation
Current guidelines are based on weak or moderate level of evidence (small studies or opinion)
The accurate diagnosis of miscarriage is fundamental, as any error may be associated with inadvertent termination of a viable pregnancy

4. 720 citations reviewed, 23 met search criteria
Accuracy of first-trimester ultrasound in the diagnosis of early embryonic demise: a systematic review
Jeve Y et al., UOG 2011
Search of:
MEDLINE (1951 to 2011)
Embase (1980 to 2011)
Cochrane Library
720 citations reviewed, 23 met search criteria
Eight articles involving a total of 872 women were included

5. Results Best criteria have 95% CI range of 0.96 to 1.00
Jeve Y et al., UOG 2011 Nov

6. Conclusions Conclusions
First systematic review of ultrasound diagnosis of miscarriage
Studies are 15–20 years old, small numbers of miscarriage, reference standards were poor (method of miscarriage confirmation)
Various cut-off values used (4–6mm for CRL, 13–25mm for MSD), making pooling of data impossible
Best (most specific) criteria appeared to be MSD > 25mm with a missing embryo or MSD > 20mm with a missing yolk sac
These criteria had a 95% CI of 0.96–1.00, therefore up to 4 out of 100 diagnoses of early fetal demise may be wrong
Jeve Y et al., UOG 2011 Nov

7. Limitations of current definitions of miscarriage using mean gestational sac diameter and crown–rump length measurements: a multicenter observational study
Abdallah Y et al., UOG 2011 (a)
Gestational sac and embryonic growth are not useful as criteria to define miscarriage: a multicenter observational study.
Abdallah Y et al., UOG 2011 (b)

8. Multicenter observational study of 1060 women in four London hospitals
Inclusion criteria:
- Intrauterine pregnancy of uncertain viability (IPUV) at sonography
- IPUV defined as an MSD < 20mm with no obvious yolk sac/embryo or CRL < 6mm with no fetal heart activity
Exclusion criteria:
- women clinically unstable
- women who subsequently underwent uterine evacuation
2D-transvaginal scans (6–12 MHz) at 0
and 7–14 days later
Abdallah Y et al., UOG 2011 (a)

9. Results: 1st scan cut-off values
1060 IPUV
473 (44.6%) viable at 11–13-week scan
587 (55.4%) non-viable at follow-up scans
1st scan
Yolk sac - NO
Embryo - NO
MSD > 16mm FPR 4.4%
MSD > 20mm FPR 0.5%
MSD ≥ 21mm FPR 0%
Yolk sac - YES
Embryo - NO
MSD > 16mm FPR 2.6%
MSD > 20mm FPR 0.4%
MSD ≥ 21mm FPR 0%
Yolk sac - YES
Embryo - YES
CRL > 4mm FPR 8.3%
CRL > 5mm FPR 8.3%
CRL ≥ 5.3mm FPR 0%
*FPR, false-positive rate for miscarriage at subsequent scans
Abdallah Y et al., UOG 2011 (a)

10. Results: 2nd scan growth rate
1060 IPUV
Subset of 359 patients where a gestational sac was seen on the second scan 7–14 days later
2nd scan
Significant overlap of MSD and CRL growth between viable and non-viable pregnancies
Failure to visualize a yolk sac or embryo on the follow-up scan was always associated with miscarriage
Abdallah Y et al., UOG 2011 (b)

11. Prospective cross-sectional study 54 women at 6–9 weeks
Clinical implications of intra- and interobserver reproducibility of transvaginal sonographic measurement of gestational sac and crown–rump length at 6–9 weeks' gestation
Pexsters A et al., UOG 2011
Prospective cross-sectional study
54 women at 6–9 weeks
Observers blinded
CRL measured from the outer ends
Gestational sac measured in three planes
CRL and MSD measured twice by each observer

12. Results
Based on 95% CI, for a given CRL of 6mm as measured by one observer, the second observer’s measurement may range from 5.4 to 6.7mm
Similarly, given an MSD of 20mm as measured by one observer, the measurement for the second observer may range from 16.8 to 24.5mm
Pexsters A et al., UOG 2011

13. Summary
Data from these studies show that current definitions used to diagnose miscarriage are potentially unsafe
Significant interobserver variability may be associated with a misdiagnosis of miscarriage
Current national guidelines should be reviewed to avoid inadvertent termination of wanted pregnancy
Large prospective studies with agreed reference standards are urgently required