Current role of ultrasound in
detection and management of
pregnancies complicated by fetal
growth restriction
FGR : Magnitude of the problem
* Perinatal mortality 120/1000
* 2nd leading contributor to perinatal
mortality rate
* 40% of all stillbirths are IUGR
What is in a name ?
Intrauterine growth retardation
Intrauterine growth restriction
Fetal growth restriction
Small for gestational age
(IUGR)
(IUGR)
(FGR)
(SGA)
Definition : Fetal growth restriction
* Ultrasound estimated fetal weight or abdominal
circumference suboptimal for gestational age
* FGR = FETAL diagnosis ( not neonatal )
* Defining threshold :
< 10th centile for gestational age
< 5th centile for gestational age (worse outcome)
Definition : Small for gestational age
(SGA)
* Birth weight suboptimal for gestational
age
* SGA = NEONATAL diagnosis (not fetal)
* Defining threshold :
< 10th centile for gestational age
Birth ratio : Actual birth weight / Expected
birth weight
SMALL FETUS
CHECK DATING OF THE
PREGNANCYPREVIOUS DATING
SCAN
EXAMINE FOR:
-FETAL BIOMETRY
-FETAL
ABNORMALITIES/MARKERS
-FETAL MOVEMENTS
-AMNIOTIC FLUID INDEX
-DOPPLERS
-SYMMETRICALLY
SMALL
-NO ANOMALIES/
MARKERS
-NORMAL ACTIVITY
-NORMAL AMNIOTIC
FLUID
-NORMAL DOPPLERS
ASSYMMETRICALLY SMALL
-NO ANOMALIES / MARKERS
-REDUCED ACTIVITY
-REDUCED AMNIOTIC FLUID
-ABNORMAL UTERINE OR
FETOPLAC, DOPPLERS
-SYMMETRICALLY OR
ASSYMMETRICALLY SMALL
-FETAL ANOMALIES AND/OR
ABNORMAL MARKERS
-ACTIVITY NORMAL OR
REDUCED
-AMNIOTIC FLUID REDUCED,
NORMAL OR INCREASED
WRONG DATES OR
CONSTITUTIONALLY SMALL
FETUS
REPEAT SCAN IN 2-4 WEKS TO
ENSURE LINEAR FETAL
GROWTH
PLACENTAL
INSUFFICIENCY
-UTERINE/FETOPLAC
DOPPLER USUALLY NORMAL
FETAL
ABNORMALITY
SERIAL GROWTH
SCANS AND
DOPPLERS TO
TIME DELIVERY
OFFER INVASIVVE
ASSESSMENT
CONGENITAL INFECTION
SCREEN
SMALL FETUS
CHECK DATING OF THE
PREGNANCYPREVIOUS DATING
SCAN
EXAMINE FOR:
-FETAL BIOMETRY
-FETAL
ABNORMALITIES/MARKERS
-FETAL MOVEMENTS
-AMNIOTIC FLUID INDEX
-DOPPLERS
-SYMMETRICALLY
SMALL
-NO ANOMALIES/
MARKERS
-NORMAL ACTIVITY
-NORMAL AMNIOTIC
FLUID
-NORMAL DOPPLERS
-SYMMETRICALLY OR
ASSYMMETRICALLY SMALL
-NO ANOMALIES / MARKERS
-REDUCED ACTIVITY
-REDUCED AMNIOTIC FLUID
-ABNORMAL UTERINE OR
FETOPLAC, DOPPLERS
ASSYMMETRICALLY SMALL
-FETAL ANOMALIES AND/OR
ABNORMAL MARKERS
-ACTIVITY NORMAL OR
REDUCED
-AMNIOTIC FLUID REDUCED,
NORMAL OR INCREASED
WRONG DATES OR
CONSTITUTIONALLY SMALL
FETUS
REPEAT SCAN IN 2-4 WEKS TO
ENSURE LINEAR FETAL
GROWTH
PLACENTAL
INSUFFICIENCY
-UTERINE/FETOPLAC
DOPPLER USUALLY NORMAL
FETAL
ABNORMALITY
SERIAL GROWTH
SCANS AND
DOPPLERS TO
TIME DELIVERY
OFFER INVASIVVE
ASSESSMENT
CONGENITAL INFECTION
SCREEN
SMALL FETUS
CHECK DATING OF THE
PREGNANCYPREVIOUS DATING
SCAN
EXAMINE FOR:
-FETAL BIOMETRY
-FETAL
ABNORMALITIES/MARKERS
-FETAL MOVEMENTS
-AMNIOTIC FLUID INDEX
-DOPPLERS
-SYMMETRICALLY
SMALL
-NO ANOMALIES/
MARKERS
-NORMAL ACTIVITY
-NORMAL AMNIOTIC
FLUID
-NORMAL DOPPLERS
-SYMMETRICALLY OR
ASSYMMETRICALLY SMALL
-NO ANOMALIES / MARKERS
-REDUCED ACTIVITY
-REDUCED AMNIOTIC FLUID
-ABNORMAL UTERINE OR
FETOPLAC, DOPPLERS
ASSYMMETRICALLY SMALL
-FETAL ANOMALIES AND/OR
ABNORMAL MARKERS
-ACTIVITY NORMAL OR
REDUCED
-AMNIOTIC FLUID REDUCED,
NORMAL OR INCREASED
WRONG DATES OR
CONSTITUTIONALLY SMALL
FETUS
REPEAT SCAN IN 2-4 WEKS TO
ENSURE LINEAR FETAL
GROWTH
PLACENTAL
INSUFFICIENCY
-UTERINE/FETOPLAC
DOPPLER USUALLY NORMAL
FETAL
ABNORMALITY
SERIAL GROWTH
SCANS AND
DOPPLERS TO
TIME DELIVERY
OFFER INVASIVVE
ASSESSMENT
CONGENITAL INFECTION
SCREEN
“ I AM A FETUS IN THE WOMB
I FEAR IT MAY BECOME MY TOMB
IF ONLY I COULD GIVE A SHOUT
TO MAKE MY DOCTOR GET ME OUT!”
UNKNOWN MEDICAL STUDENT
DUBLIN, UK 1982
Dilemmas in FGR
How to monitor
cCTG
Arterial Dopplers
Venous Dopplers
Biophysical profile
When to deliver?
Dilemmas in management of FGR
* Severe FGR due to placenta dysfunction
- Progressive
- No treatment to reverse the process
* Timing of delivery
- Risks : prematurity vs continued intrauterine
life
* Objective
- Buy time to reduce prematurity risks, but
deliver prior to organ damage
* Question : Can this be accomplished ?
* Answer : DOPPLER
Hecher K et al : Monitoring of fetuses with IUGR :
a longitudinal study.
UOG 2001; 18:564-570
Baschat AA et al: The sequence of changes in
Doppler and BPP as severe FGR worsens.
UOG 2001; 18: 571-577
Ferrazzi E et al : Temporal sequence of abnormal
Doppler changes in severe IUGR.
UOG 2002; 19: 140-146
Phases of placental dysfunction causing FGR
Patterns of clinical progression in early FGR
STV and metabolic acidosis in IUGR
STV (msec )
<2.6
2.6-3.0
> 3.0
----------------------------------------------------------------------------------Gestation (wks )
25-38
26 – 38
27 – 37
Metabolic acidosis *
10.3%
4.3%
2.7%
IUFD
24.1%
4.3%
0.0%
----------------------------------------------------------------------------------* pH< 7.12 ; base deficit >12 mmol/l
Pardey J et al AJOG 2002; 186:1095-1103
IUGR : DV , STV and perinatal mortality
n
alive
IUFD
NND
----------------------------------------------------------------------------------Both abnormal 33
20
6
7
13/33 (39%)
Both normal/or
one abnormal
60
56
0
4
4/60 (7%)
----------------------------------------------------------------------------------Total
93 76
6
11
Hecher K et al, UOG 2001
Derks JB et al:
The effects of maternal betamethasone
administration on the fetus. BJOG 1995; 102:40-46
within 48 hours after initial betamethasone
administration :
* Reduction of fetal movements
* Reduction of fetal breathing movements
* Reduction of STV on NST
All changes disappeared after 4 days following
treatment
Thuring A et al: Effect of maternal betamethasone on
fetal and uteroplacental blood flow .UOG 2011; 37: 668672
within 48 hours after initial betamethasone
administration :
* decreased UMA diastolic flow
* decreased DV flow at time of atrial contraction
* no changes of MCA and UTA flows
All changes disappeared after 4 days following treatment
Patterns of clinical progression in late FGR
LATE-ONSET FGR AND NEURODEVELOPMENTAL DELAY
Late-onset FGR > 34 wks
Normal or UMAPI
MCAPI
Intracerebral Redistribution of Blood Flow
Frontal Lobes
Basal ganglia
Neurodevelopmental delay
Neonatal period
Early childhood
Socialinteractive
attention
Impaired
-Performance attention
-Communication
-Problem solving
-Emotions
-Social function
Cruz-Martinez R et al, AJOG 2009
Review of determinants of fetal
neurodevelopment.
FGR monitoring – key points
* UMA flow is useful parameter for assessment of high-risk population not a
screening test
* UMA flow unless it is severely abnormal does not tell us anything about fetal
condition
* MCA flow reflects the extent of fetal “brain sparing”=sign of arterial
redistribution as fetal response to hypoxemia
* One of drawbacks of existing fetal arterial redistribution is subsequent
development of oligohydramnios
*Computerized CTG is currently the best parameter to detect fetal acidosis by
decreased STV ( < 3 msec)
* Ductus venosus flow indirectly reflects the efficiency of the fetal heart and
seems to correlate with the presence or absence of metabolic acidosis
* Longitudinal monitoring ( at least 3 detailed studies) facilitates definition of
trends of evaluated parameters in FGR. Different fetuses are showing different
responses to impaired placental function i.e. all fetuses should be used as their
own control
FGR delivery timing – key points
* As IUGR fetus decompensates there are progressive
Doppler velocimetry changes
* These Doppler changes usually tend to follow a consistent
pattern and largely occur prior to abnormalities in BPP.
* Abnormal DVPI and STV values are important indicators
for the optimal timing of delivery before 32wks of gestation
* Metabolic acidosis, not necessarily hypoxia, correlates
with neurological outcome in the infant
* Gestational age overrides the effect of fetal cardiovascular
condition until 32-34 weeks
* Neurodevelopment is affected by severely abnormal
UMA and DV flows in early-onset FGR and by abnormal
MCA flow in late-onset FGR
FGR MANAGEMENT PROTOCOL
26-34 weeks
NST & Doppler studies
NST Reactive
34-36 weeks
NST & Doppler studies
NST Non-Reactive
UMA Doppler
Reassuring
UMA Doppler
Non-Reassuring
Repeat in 1W
Venous Doppler
BPP < 4
Reassuring
Non-reassuring
Repeat in 1W
Deliver
BPP 6
Both Tests
Reassuring
Either Test
Non-Reassuring
Repeat in 1W
Deliver
Deliver
Repeat in
6-24 hours
Callen 2010
LOOK TO THE FUTURE