prediction of viability

1. prediction of early pregnancy
outcomes
Narendra Malhotra
Jaideep Malhotra
Neharika Malhotra Bora
Rishabh Bora
Keshav Malhotra
www.malhotrahospitals.com

2. Outline of this Presentation
Ultrasound diagnosis of early pregnancy failure
Definition/Terminologies
Sonographic criteria
Guidelines for diagnosis
Issues
Current Recommendations
Safe cut off level
Follow up

3. Definite signs of Early Pregnancy
Failure
• Absence of cardiac activity in an embryo
-Embryonic demise
• Absence of yolk sac/embryo in a large GS
-Blighted ovum
FAILED PREGNANCY

4. Definite signs of Early Pregnancy
Failure
What is the descriminatory size for safe diagnosis?
Mean Sac diameter
CRL

5. Definite signs of Early Pregnancy
Failure
What is the descriminatory size for safe diagnosis?
TAS TVS
Gestational
sac
(MSD)
> 20mm with out YS > 8mm without
YS
> 25mm without
cardiac activity
>16mm without
embryo cardiac
activity
Nyberg, 1986
Threatened Abortion: Sonographic distinction of normal and abnormal pregnancy

6. Definite signs of Early Pregnancy
Failure
What is the descriminatory size for safe diagnosis?
TAS TVS
Embryo
(CRL)
> 8mm1
> 4mm 2
> 5mm 1,3
1
Pennell, 1991
Prospective comparison of vaginal and abdominal sonography in normal early pregnancy
2
Levi, 1990
TVS: Demonstration of cardiac activity in embryos of less than 5mm in CRL
3
Brown, 1990
Diagnosis of early embryonic demise by TVS

7. GUIDELINES FOR DIAGNOSIS
OF EARLY PREGNANCY FAILURE
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, >9mm(TAS)
• MSD > 8mm without a visible
yolk sac, 20mm (TAS)
• MSD > 16mm without a
visible embryo, (25mm (TAS)
LEVEL 11-2 a
AIUM, 2007
• CRL > 5mm (TVS) with no
visible cardiac activity
American College
of Radiologists
(ACR) 2000
• CRL > 5mm with no
visible cardiac activity
• MSD > 16mm without a
visible embryo or yolk sac

8. GUIDELINES FOR DIAGNOSIS
OF EARLY PREGNANCY FAILURE
Practice in the
Philippines
• CRL > 5mm with no
visible cardiac activity
• MSD > 18mm without a
visible embryo or yolk sac
Australian Society
for Ulltrasound in
Medicine (ASUM)
• CRL > 6mm with no
visible cardiac activity
• MSD > 20mm without a
visible embryo or yolk sac
Hongkong College
of Obstetricians
and Gynaecologists
(HKCOG) 2004
• CRL > 5mm (TVS), >9mm
(TAS) with no visible
cardiac activity
• MSD ≥ 20mm without a
visible embryo or yolk sac
OB-GYN USG for practicing
Clinician 2nd
Ed
FOGSI GUIDELINES A FEW YEARS BACK
MSD >20without YS/E :CRL >6mm without cardiac activity
IFUMB/ICMU and ICOG

10. Author Type of Study Study Pop (n) Exam Sonographic criteria used
Nyberg (1986) Cohort,
Retrospective
168 TAS No embryo, MSD >25mm,
No yolk sac, MSD > 20mm
Nyberg (1987) Cohort
Prospective
83 TAS No embryo, MSD >25mm,
No yolk sac, MSD > 20mm
Scott (1987) Cohort
Prospective
102 TAS Empty GS > 26mm
Levi (1988) Cohort
Prospective
55 TVS No YS and MSD > 8mm
No embryo, cardiac > 16mm
Levi (1990) Cohort
retrospective
71 TVS No cardiac activity, CRL < 5mm

11. Best criteria
have 95% CI
range of
0.96 to 1.00

12. Best criteria:
An empty gestational sac > 25mm
Missing yolk sac with gestational sac > 20mm:
Specificity 1, 95% CI range of 0.96 to 1.00
***Up to 4 in every 100 diagnosis may be false positive

14. 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
2D-transvaginal scans (6–12 MHz)
at 0 and 7–14 days later

15. MSD 16mm: FPR (viable pregnancy): 4.4%
MSD 20mm: FPR is 0.5%
MSD 21mm: vFPR is 0

16. CRL 4mm and 5mm: FPR= 8.3%
CRL 5.3mm: FPR=0

17. ** There are still a number of cases at or around
the critical decision boundaries(descriminatory level)
used to define miscarriage.
** There is a need to increase the cut off level to
a safer level.

19. 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

20. Pexsters A et al., UOG 2011
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

21. • 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

22. RECOMMENDATIONS
Empty GS = an MSD of 25 mm with out yolk sac
or embryo
Embryonic demise= A CRL of 7mm with
no cardiac activity
Wait for 7-10 days before a repeat scan if results are
below the descriminatory level.

23. SUMMARY
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).
Diagnosis of Early Pregnancy Failure
The descriminatory size of 5mm for CRL
and 20mm for GS may be unsafe cut off levels and
may result to inadvertent termination of pregnancy.

24. SUMMARY
A new cut off level of MSD of 25mm empty sac and
CRL of 7mm without cardiac activity to make a
diagnosis of pregnancy level is being considered
Diagnosis of Early Pregnancy Failure
National guidelines should be reviewed, a diagnosis
of pregnancy failure should have no chance of error
(100% specificity).