Defining Early pregnancy loss

Douglas Dumbrill

MRCOG FCOG

Life Vincent Pallotti and Groote Schuur Hospitals

Pain and / or bleeding in early pregnancy

• viable intra- uterine pregnancy

• Failed or failing pregnancy

• Ectopic pregnancy

Is there a chance of a viable pregnancy ?

…. two clinical contexts

• Intrauterine pregnancy of unknown VIABILITY

• Pregnancy of unknown LOCATION

0 1 2 3 4 5 6 7 8 9 10

Gestational age (weeks)

ovulation

implantation

βhCG > 25 iu/l

βhCG > 1000 iu/lgestational sac

Landmarks

Yolk sac CRL and fetal heart activity

Four weeks gestation

Gestational sac diameter

Grisolia et al, 1993

Five weeks gestation

• ring-like structure

• echogenic rim

• eccentric

• visible by 5+2

Yolk sac

• First visible 4+6 – 6+4

• Mean gestational sac diameter 5 – 12mm

• hCG up to 7000 iu/l

• Corresponds to secondary yolk sac embryologically

• Functions:

early haematopoesis

transport of nutritive substances to embryo

primordial germ cells

Six weeks gestation

• Embryo first visible 5+4 – 6+4

• Mean gestational sac diameter 10 – 18mm

• Straight line adjacent to yolk sac, close to trophoblast

• Embryonic length 4 – 10mm

• Identified by cardiac activity

Fetal heart rate

Take care not to include the yolk sac

Six weeks gestation

Seven weeks gestation

vitelline ductamnion

0 1 2 3 4 5 6 7 8 9 10

Gestational age (weeks)

ovulation

implantation

βhCG > 25 iu/l

βhCG > 1000 iu/lgestational sac

Landmarks

Yolk sac

CRL 10 mm FH activity

CRL 15

CRL 21

CRL 30

Mean Gestational sac diameter 21mm CRL 6.5 mm and no FH

Mean Gestational sac diameter 21mm CRL 6.5 mm and no FH

• Non viable / Miscarriage

Mean Gestational sac diameter 21mm CRL 6.5 mm and no FH

• Non viable / Miscarriage

• Too early

– would re scan

Mean Gestational sac diameter 21mm CRL 6.5 mm and no FH

• Non viable / miscarriage

• Too early

– would re scan

• Unsure

– Do bloods

Pre 2012 : “ pregnancy of uncertain viability “

RCOG (2006 )

Gestational Sac > 20 mm

Embryo > 6mm

ACR ( 2000)

Gestational Sac >16 mm

Embryo > 5mm

Why the change ?

Why the change ? Nov 2011 Vol 38 Number 5

• “ clinicians cannot be certain that the current guidelines afford them a 100 % specificity in the diagnosis of miscarriage “

• “ that is to say that it is possible for some women with a viable pregnancy will be inappropriately labeled as having a miscarriage “

In brief : 1060 women attending EPAU’s LondonProspective observational TVSIndication : bleeding, pain , past historyEnd point 11-14 week viability

• Demonstrated that with MSD > 20 mm

– One viable pregnancy for 200 classified as a miscarriage

– False positive rate was 4.4 % if MSD > 16 mm

• Recommended that increasing the CRL/MSD definition of miscarriage , the false positive rates fall to zero

• “ slow or absent growth of MSD is not necessarily associated with a miscarriage “

• “ Failure to visualise a yolk sac or embryo on rpt scan was a defining feature of a failed pregnancy “

• A TVS should be performed in all cases where there is any doubt about the diagnosis and /or a woman requests a repeat scan and this should be performed at an interval of at least one week from the initial scan before medical or surgical measures are undertaken .

• No growth in gestational sac size or CRL is strongly suggestive of a non viable pregnancy in the absence of embryonic structures

New guidelines for the diagnosis of miscarriage

RCOG

Gestational Sac > 25 mm

Embryo > 7 mm

ACOG /ACR / AJUM/SRU

Gestational Sac > 25 mm

Embryo > 7mm

Mean Gestational sac diameter 21mm CRL 6.5 mm and no FH

• Miscarriage

• Too early

– would re scan

• Unsure

– Do bloods

Mean Gestational sac diameter 21mm CRL 6.5 mm and no FH

• Miscarriage

• Too early

– would re scan

• Unsure

– Do bloods

But ..... More Questions

• What about the failed pregnancy that never reaches this 7/25 cut off ?

• When should we repeat the scan ?

• What should we expect to find on repeat scan to diagnose miscarriage ?

• What about gestational age ?

Diagnosis of miscarriage trial ( DOM )

CRL 7.1 mm

MSD 27 mm with no visible emnryo

Scan 2 weeks apart intrauterine GS with YS but no embryo

Miscarriage management

• Appropriate training and equipment

• Be aware of new diagnostic criteria

• Stipulate ultrasound findings on repeat scan to define miscarriage

• Manage patient expectation on the repeat scan

• Remember expectant management is unlikely to be harmful but intervention certainly can be

Thank you for your attention