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 (IUGR)Intrauterine growth restriction (IUGR)Fetal growth restriction (FGR)Small for gestational age (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 PREGNANCY- PREVIOUS

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

WRONG DATES OR

CONSTITUTIONALLY SMALL FETUS

REPEAT SCAN IN 2-4 WEKS TO ENSURE LINEAR FETAL

GROWTH

ASSYMMETRICALLY SMALL

-NO ANOMALIES / MARKERS

-REDUCED ACTIVITY

-REDUCED AMNIOTIC FLUID

-ABNORMAL UTERINE OR FETOPLAC, DOPPLERS

PLACENTAL INSUFFICIENCY

SERIAL GROWTH SCANS AND

DOPPLERS TO TIME DELIVERY

-SYMMETRICALLY OR ASSYMMETRICALLY SMALL

-FETAL ANOMALIES AND/OR ABNORMAL MARKERS

-ACTIVITY NORMAL OR REDUCED

-AMNIOTIC FLUID REDUCED, NORMAL OR INCREASED

-UTERINE/FETOPLAC DOPPLER USUALLY NORMAL

FETAL ABNORMALITY

OFFER INVASIVVE ASSESSMENT

CONGENITAL INFECTION SCREEN

SMALL FETUS

CHECK DATING OF THE PREGNANCY- PREVIOUS

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

WRONG DATES OR

CONSTITUTIONALLY SMALL FETUS

REPEAT SCAN IN 2-4 WEKS TO ENSURE LINEAR FETAL

GROWTH

ASSYMMETRICALLY SMALL

-NO ANOMALIES / MARKERS

-REDUCED ACTIVITY

-REDUCED AMNIOTIC FLUID

-ABNORMAL UTERINE OR FETOPLAC, DOPPLERS

PLACENTAL INSUFFICIENCY

SERIAL GROWTH SCANS AND

DOPPLERS TO TIME DELIVERY

-SYMMETRICALLY OR ASSYMMETRICALLY SMALL

-FETAL ANOMALIES AND/OR ABNORMAL MARKERS

-ACTIVITY NORMAL OR REDUCED

-AMNIOTIC FLUID REDUCED, NORMAL OR INCREASED

-UTERINE/FETOPLAC DOPPLER USUALLY NORMAL

FETAL ABNORMALITY

OFFER INVASIVVE ASSESSMENT

CONGENITAL INFECTION SCREEN

SMALL FETUS

CHECK DATING OF THE PREGNANCY- PREVIOUS

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

WRONG DATES OR

CONSTITUTIONALLY SMALL FETUS

REPEAT SCAN IN 2-4 WEKS TO ENSURE LINEAR FETAL

GROWTH

ASSYMMETRICALLY SMALL

-NO ANOMALIES / MARKERS

-REDUCED ACTIVITY

-REDUCED AMNIOTIC FLUID

-ABNORMAL UTERINE OR FETOPLAC, DOPPLERS

PLACENTAL INSUFFICIENCY

SERIAL GROWTH SCANS AND

DOPPLERS TO TIME DELIVERY

-SYMMETRICALLY OR ASSYMMETRICALLY SMALL

-FETAL ANOMALIES AND/OR ABNORMAL MARKERS

-ACTIVITY NORMAL OR REDUCED

-AMNIOTIC FLUID REDUCED, NORMAL OR INCREASED

-UTERINE/FETOPLAC DOPPLER USUALLY NORMAL

FETAL ABNORMALITY

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 When to deliver?cCTGArterial DopplersVenous DopplersBiophysical profile

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/orone 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: 668-672

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

Intracerebral Redistribution of Blood Flow

Impaired-Performance attention-Communication-Problem solving-Emotions-Social function

Basal ganglia Frontal Lobes

MCAPI

Neurodevelopmental delay

Social-interactive attention

Normal or UMAPI

Early childhoodNeonatal period

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

UMA DopplerNon-Reassuring

NST Non-ReactiveNST Reactive

26-34 weeks NST & Doppler studies

UMA DopplerReassuring

Either TestNon-Reassuring

Both TestsReassuring

34-36 weeks NST & Doppler studies

Repeat in 1W

Non-reassuring

Deliver

Reassuring

Venous Doppler

Repeat in 1W

Repeat in 1W Deliver

Callen 2010

BPP < 4

BPP 6 Repeat in 6-24 hours

Deliver

LOOK TO THE FUTURE