Transcript Slide 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)
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
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
American College
of Radiologists
(ACR) 2000
• CRL > 5mm with no visible
cardiac activity
• MSD > 16mm without a
visible embryo or yolk sac
CRL, crown–rump length
MSD, mean sac diameter
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
Accuracy of first-trimester ultrasound in the diagnosis of early
embryonic demise: a systematic review
Jeve Y et al., UOG 2011
Search of:
1. MEDLINE (1951 to 2011)
2. Embase (1980 to 2011)
3. Cochrane Library
720 citations reviewed, 23 met search criteria
Eight articles involving a total of 872 women were included
Results
Best criteria
have 95% CI
range of
0.96 to 1.00
Jeve Y et al., UOG 2011 Nov
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
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)
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)
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
Yolk sac - YES
Embryo - NO
Yolk sac - YES
Embryo - YES
MSD > 16mm FPR 4.4%
MSD > 20mm FPR 0.5%
MSD ≥ 21mm FPR 0%
MSD > 16mm FPR 2.6%
MSD > 20mm FPR 0.4%
MSD ≥ 21mm FPR 0%
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)
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)
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
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
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