The SGA BabyManagement, the role of scanning and Doppler,and when to deliver
22 November 2019
Dr Ngaire Anderson Prof Lesley McCowan
SGA: identification
2
Gardosi J. Maternal and fetal risk factors for stillbirth: population based study. BMJ 2013
Impact of detection on stillbirth in SGA
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Lindqvist PG. Does antenatal identification of small-for-gestational age fetuses significantly improve their outcome? Ultrasound Obs Gynecol 2005Gardosi J. Maternal and fetal risk factors for stillbirth: population based study. BMJ 2013Nohuz E. Is prenatal identification of SGA useful? Ultrasound Obs Gynecol 2019
~60% reduction
Slide courtesy F Figueras
SGA: when?
4Groom et al BJOG 2007;114:478–484.
% by gestation at delivery 85% of SGA babies (n=17,885) born at term
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http://www.healthpoint.co.nz/public/new-zealand-maternal-fetal-medicine-network/?solo=otherList&index=5
NZMFM SGA Guideline (updated 2014)
GUIDELINE FOR THE MANAGEMENT OF SUSPECTED SMALL FOR GESTATIONAL AGE SINGLETON PREGNANCIES AND INFANTS AFTER 34 WEEKS’ GESTATION
This guideline has been developed to achieve a more consistent approach to management of small for gestational age (SGA) singleton pregnancies and infants in New Zealand.
Algorithm & SGA Risk Assessment Tool for New Zealand:Screening and assessment of fetal growth in singleton pregnancies
Adapted from NHS England stillbirth ‘care bundle’ and based on NZ MFM SGA Guideline
Serial growth scans until birth Plot estimated fetal weight (EFW) on customised chart Plot individual fetal measurements on population chart
Major Risk for SGARecommend specialist referralConsider low dose aspirin 100mg nocte
Maternal Risk Factors□ Maternal age >40 years□ Continued smoker after 16 weeks (>10/day) □ Recreational drugsPrevious Pregnancy History□ Previous SGA baby (<10th cust centile)□ Previous stillbirthMaternal Medical History□ Chronic hypertension□ Diabetes with vascular disease□ Renal impairment□ Anti-phospholipid syndrome Current Pregnancy ComplicationsEarly Pregnancy □ PAPP-A <0.4 MoM (if MSS1 performed) □ Heavy bleeding <20 weeks Late Pregnancy□ Pre-eclampsia /severe gestational hypertension □ Antepartum haemorrhage
Abnormal growth:• EFW<10th centile • Abdominal circumference (AC) ≤5th centile• Serial measurements not following curve >30% in AC or
EFW
Low Risk Care• Serial assessment of fundal height (FH) (not more frequently than 2 weekly) from
26-28 weeks until birth • FH plotted on customised chart.
Suspected reduced growth:• FH <10th centile • FH crossing centiles by >30%
Normal growth
Low Risk of SGA No known major risk factors
Referral for ultrasound: measure• Estimated fetal weight (EFW)• Individual fetal measurements• Umbilical artery Doppler if reduced growth or SGA suspected
Refer to SGA guideline pathway http://www.healthpoint.co.nz/public/new-zealand-maternal-fetal-medicine-network/?solo=otherList&index=5
Fundal height measurement likely to be unreliable: Large fibroids BMI 35+ Third trimester scanning based on local guidelines and resources
1 or more risk factors
No major risk factors
Updated April 2019
Suggested Schedule of Growth Scans Depending on Local Resources / Guidelines
High risk early onset SGA*e.g. severe medical, previous SGA birth <34wk or stillbirth,↓ PAPP-A
Monthly growth scans from 24 weeks’ to birth
Consider uterine artery Doppler at 20 or 24wks
High risk late onset SGA* e.g. previous SGA born > 34 wk,
mild chronic hypertension, age >40
Monthly growth scans from 28-30 weeks’ to birth e.g. 30, 34, 38 weeks
Mod risk late onset SGA* e.g. smoke >10/day or FH
measurement likely to be unreliable (BMI 35+, fibroids)
Scan 30-32 & 36-38 weeks’
Fortnightly scans until birth. Plot individual measurements and estimated fetal weight (EFW) on customised chart.
Manage as per NZMFM SGA Guidelinehttp://www.healthpoint.co.nz/public/new-zealand-maternal-fetal-medicine-network/?solo=otherList&index=5
SGA or poor interval growthEFW<10th centile
Abdominal circumference (AC) ≤ 5th centileSerial measurements (AC or EFW) cross centiles by > 30%
* Early onset SGA=SGA baby born <34 weeks, late onset SGA = SGA baby born >34 weeks Updated April 2019
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SGA vs FGR
Suspected suboptimal fetal growth
• SGA = EFW <10th centile on customised chart
• AC<5th centile on population chart
FGR*
• EFW or AC <3rd centile
OR any two of:
• EFW or AC <10th centile
• Cerebroplacental ratio (CPR) <5th centile OR Umbilical artery PI >95th centile
• EFW or AC crossing centiles (by ~30%)
x
* Gordijn et al. Consensus definition of fetal growth restriction: a Delphi procedure. Ultrasound Obstet Gynecol. 2016
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x
x
x
x
x
x
x
x
•All measurements crossing centiles
•AC <5th centile
EFW <10th
Suspected suboptimal fetal growth
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x
x
x
x
x
x
x
x
x
x
x
x
• Discordant AC• AC crossing
centiles
EFW crossing centiles
Suspected suboptimal fetal growth
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x
x
x
x
x
x
x
x
• All measurements crossing centiles
EFW in normal range
Suspected suboptimal fetal growth
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x
x
x
x
x
x
x
x
• All measurements increasing
• AC within normal range
EFW <10th centile
Suspected suboptimal fetal growth
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• Drop off @ 32/40• Subsequently all
measurements increasing
•EFW <10th centile•Growing
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
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Suspected suboptimal fetal growth
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Umbilical artery Doppler studies
• Reflects resistance to placental blood flow
• Use leads to:
• 30% reduction in perinatal deaths
• 30% reduction in antenatal hospital admissions
• ↓ LSCS (elective and emergency)
• Fewer IOL
Alfirevic, Stampalija, Dowswell, Cochrane Library 2017
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Normal vascularity
Very abnormal vascularity
http://slideplayer.com/slide/5910115/19/images/37/Acrylic+casts+of+the+umbilical+arterial+vascular+tree+within+a+placental+lobule..jpg
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Umbilical Doppler & neonatal outcome
Doppler Results Normaln=1650
95-99%n=193
>99%n=239
AEDVn=96
Gestation delivery 38.3 37.6 35.8 31.1
Birthweight (g) 3097 2713 2148 1198
SGA 18% 38% 60% 81%
Admitted NICU 18% 23% 47% 90%
Perinatal Mortality:1000 15.8 41.5 50.2 239
Trudinger et al BJOG 1991 98, 378-84
Suspected suboptimal fetal growth
• Abdominal circumference <10th centile• Measurements (especially AC) crossing centiles• Head circumference >> abdominal circumference• EFW on customised chart < 10th centile or crossing centiles → GROW chart with woman to scan so sonographer can plot EFW
Preeclampsia• Doppler abnormalities may occur before IUGR
When to perform Umbilical artery Doppler
17No current role for umbilical Doppler in low risk women
~30% obliteration of small placental vessels before ↑ umbilical artery Doppler indices
• abnormal Doppler = significant placental vascular disease
• normal umbilical Doppler can have placental vascular & other placental dysfunction
SGA with normal umbilical Doppler • 60% -70% of all SGA• ≈ 90% SGA >32-34 weeks• not just small normal babies
SGA with normal Umbilical artery Doppler
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UA Doppler by gestation in suspected FGR
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Normal UARaised UAAREDV
Savchev Fetal Diagn Ther 2014; 36:99-105
Perinatal outcomes SGA >34w normal Umb a Doppler
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Rochelson, B.L.. AJOG, 1987; Burke, G BMJ 1990; Bekedam, D.J. Early Hum Dev 1900;Trudinger, B.J. BJOG, 1991; James , D.K. AJOG, 1992; Gaziano, E.P. AJOG, 1994; Yoon, B.H. AJOG, 1994; McCowan. BJOG, 2000; Madazli M. Acta Obstet Gynecol Scand 2001; Soregaroli, M. J Matern Fetal Neonatal Med, 2002; Seyam, Y.S. Int J Gynaecol Obstet, 2002; Severi, F,M. UOG 2002; Figueras, F. 2007
% %
Placental findings: Late onset SGA with normal umbilical Doppler
21 Parra M, Placenta 201360% SGA had features of significant placental pathology
Can we identify at-risk sub-groups of late onset SGA?(normal umbilical artery Doppler)
• Cerebroplacental ratio• Middle cerebral artery (MCA) / umbilical a Doppler ratio
• Uterine artery Doppler studies• Severity of growth deviation (EFW<3rd centile)
High risk SGA / FGR?
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• Fetal response to hypoxia includes ↑ cerebral flow• Results in ↓ MCA resistance & ↓ CPR• ↓ CPR = ↑ cerebral flow indicative of hypoxia• ↓ CPR more sensitive than abnormal MCA
Cerebral Doppler in late-onset SGA
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Longitudinal changes in Doppler indices late-onset SGA.
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Doppler trends from diagnosis to delivery (n=171 SGA)
0
5
10
15
20
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UA PI UtA PI MCA PI CPR
Admission
Before delivery
p0.005
Oros D, Ultrasound Obstet Gynecol. 2011
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Abnormal CPR
Cerebral redistribution associated with ↑ perinatal morbidity• CS for fetal distress
• Neonatal acidosis
• Low 5min APGAR scores (<7)
• NICU admission
• Serious neonatal complications
• Stillbirth
Nassr J Perinat Med 2016Conde-Aqudelo Ultrasound Obstet Gynecol 2018
CS for fetal distress
NICU admission
Monteith et al Abnormal CPR and delayed neurodevelopment AJOG 2019
Abnormal CPR and neurodevelopment
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0 .1 1 1 0
O R
M o t o r
L a n g u a g e
C o g n it iv e
SGA normal UA (ref)FGR abnormal UA ( )FGR abnormal CPR ( )
3-y Bayley’s test
PORTO study
Slide courtesy F Figueras
Abnormal Uterine Doppler-suspected SGA
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Slide courtesy F Figueras
Martinez-Portilla RJ. Uterine artery Doppler & adverse outcomes in SGA: systematic review&meta-analysis (In preparation)
EFW <3rd centile
28 Savchev S, Ultrasound Obstet Gynecol 2011
132 SGA >37w: normal UA, MCA & UtA Doppler
0
5
10
15
20
25
30
CS for fetaldistress
Neonatalacidosis
perc
enta
ge
AGASGA ≥3rd centileSGA <3rd centile
Risk of SGA stillbirth by gestation
29Pillod Risk of intrauterine fetal death in SGA. AJOG 2012
• ↑ risk CS for fetal distress/ neonatal acidosis & NICU admission even when all Dopplers normal
• Higher risk of stillbirth, particularly at term • Lower threshold for delivery• Continuous fetal monitoring from onset of labour
Severe IUGR (EFW <3rd centile)
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509 SGA >37 weeks
Adverse outcome risk
26.4%
Normal CPR 23.6%
Normal UtA19.8%
EFW >p311.1%
EFW<p335%
UtA>p9540%
CPR <p542%
Late-FGR
SGA
60% of late-SGA - 86% of adverse outcomes in this group
40% of late-SGA - 14% adverse outcomes in this group
Figueras, F., et al.. Ultrasound Obstetrics & Gynecology, 2014 doi: 10.1002/uog.14714.
Late-onset FGR vs. SGA
Figueras, F., et al.. Ultrasound Obstetrics & Gynecology, 2014 doi: 10.1002/uog.14714.
Late onset SGA: When to deliver?
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RCT of management of suspected SGA >36 wks
• Abdominal circumference <10th centile
• Measurements (especially AC) crossing centiles
• EFW < 10th centile - normal & abnormal umbilical Doppler included
Randomised expectant management twice weekly surveillance vs induction within 48 hours
Outcome composite neonatal morbidity
Disproportionate Intrauterine Growth Intervention Trial DIGITAT
34 Boers et al BMJ 2010;341:c7087 doi:10.1136/bmj.c7087
Induction (n=321) Expectant (n=329)
Delivery gestation 38 w+ 0 days 39w +4 days
Birthweight (g) 2420 2550
Induction 95.6% 50.6%
Spontaneous labour 3.7% 46%
Planned CS 0.6% 3.3%
Boers et al BMJ 2010;341:c7087 doi:10.1136/bmj.c7087
DIGITAT Results
Induction (n=321) Expectant (n=329)
Preeclampsia 3.7% 7.9%*
Total CS 14% 13.7%
Neonatal morbidity 5.3% 6.1%
NICU admission 2.8% 4.0%
BWT <3rd centile 12.5 % 30.6%*
Boers et al BMJ 2010;341:c7087 doi:10.1136/bmj.c7087
DIGITAT Results
• No difference in primary outcomes with induction vs expectant management
• N.B. expectant = twice weekly BP, CTGs & liquor volume
• Induction no ↑ CS
• Induction ↓ BWT <3rd centile & ↓ preeclampsia
• Underpowered to assess perinatal death
“It is more rational to choose induction to prevent possible stillbirth on the grounds that CS not ↑”.
DIGITAT Conclusions
Boers et al BMJ 2010;341:c7087 doi:10.1136/bmj.c7087
N=292 24-months SGA >37 weeks
InductionGA at delivery
38w
Abnormalneurodevelopment*
25%
Abnormalneurobehavior
14%
ExpectantmanagementGA at delivery
39.4w
Abnormalneurodevelopment
29%
Abnormalneurobehavior
11%
SevereIUGR
AdmissionNeonatalUnit
Boers Am J Obstet Gynecol 2012; 206.
DIGITAT 2y neuro-development -behaviour
Compared with term, 33-37w babies have increased:• morbidity and mortality• costs in first year of life• special education & behavioural problems• ↑ BP, impaired lung function & infertility as adults
DIGITAT: late preterm SGA ↑ morbidity risk but also BWT <3rd centile
Late pre-term birth vs severe SGA
Late preterm risks SGA fetus in uteroSource: Lesley McCowan http://perinatal.co.za/patients/tests-and-
procedures/growth-and-doppler-ultrasound/
Morbidity score > with :
• induction <38 wks
• expectant >38 wks
• Supports delivery ~38 wks optimum
DIGITAT neonatal morbidity by gestation
Boers Am J Obstet Gynecol 2012; 206.
• No perinatal deaths in trial
• Eligible non-randomised women perinatal mortality of 4/452
~ 8/1000 compared with perinatal mortality at term 1-2/1000
• These women had higher socioeconomic status
• Suggests schedule of twice weekly surveillance in expectant management
was effective
• Induction at ~ 38 weeks cost effective
Further DIGITAT outcomes
41 Vijgen Eur J Obstet Gynecol Reprod Biol. 2013;170(2):358-363
*Scherjon S Data presented at Fetal Growth Conference 2015
RCOG standard of care = IOL for SGA at 37 wks• Oxford introduced protocol for high & low risk SGA 2014-2016• Outcomes compared to 2013-14
Veglia et al Ultrasound O&G 2018 doi: 10.1002/uog.17544
A risk stratification protocol for term SGA
Low risk SGA
• Normal umb a Doppler
• EFW <10th centile
• Normal PAPP-A
Deliver 40-41 weeks
High risk SGA (FGR)• EFW <3rd centile• CPR <5th centile• Abnormal UtA Doppler• PAPP-A <0.3 MoMs• HypertensionDeliver 37 weeks
RCOG vs Risk stratification approach
Delivery ≥39wks
Vaginal birth
Induction
CS
NICU admission
Adverse neonatal outcome
Veglia et al Ultrasound O&G 2018 doi: 10.1002/uog.17544
• FGR failure to achieve growth potential if:• AC >5th centile and ↓ by >30% between scans• EFW >10th and ↓ by >30% between scans
• Consistent with Melbourne evidencethat growth velocity ↓ of >30% from 28-36 weeks in AGA associated with• Abnormal CPR RR 2.5• Acidosis at birth RR 3.51 (>35% )
NZ Approach – growth velocity
Balloon vs. PGE2
RR (CI 95%)
Delivered in 24h 0.81 (0.3-1.11)Hyperstimulation + CTG abnormalities 0.16 (0.06-0.39)
0.12 0.250.5 1
1.1
Mechanical methods for induction of labourJozwiak M, Bloemenkamp KWM, Kelly AJ, et al 2012
Method of SGA labour induction
Late-onset SGA summary
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No MCA Dopplers
• Generate GROW chart at booking• Early pregnancy risk selection
• Low dose aspirin & specialist referral if ↑ risk
• Serial scans if ↑risk but no routine growth scans in low risk• Plot fundal height on GROW from 26 weeks• Growth scan- plot individual measurements ASUM chart & EFW
on GROW• Suspected SGA –umbilical Doppler & follow algorithm• Continue scans until delivery
NZMFM SGA Guidelines Recommendations
• Optimum gestation for delivery in SGA ≈ 38 weeks
• CS not increased by IOL
• ↓ neonatal morbidity vs earlier delivery
• ↓ preeclampsia vs expectant management
• ↓ likelihood of severe IUGR vs expectant management
• Cost effective
NZMFM SGA Guidelines Recommendations
• Balloon IOL
• Early admission in labour (don’t recommend early labour at
home)
• Continuous fetal monitoring in labour
• Recommended postnatal care of SGA infants especially
hypoglycaemia monitoring
NZMFM SGA Guidelines Recommendations
Early onset SGA
52 10/30/2019
• 503 singleton IUGR 26-32 wks + abn Umb Doppler
• Randomised to delivery according to:
• Abnormal computerised CTG (no ductus venosus Doppler studies)
• Early changes in ductus venosus - PI >95%
• Late changes in ductus a-wave at or below baseline
• Safety parameters: Reduced cCTG short term variability (STV)
• Or irrespective of STV, spontaneous repeated decelerations on CTG
• Primary outcome intact survival at 2 years
Lees et al Lancet 2015 http://dx.doi.org/10.1016/S0140-6736(14)62049-3
A waveDuctus venosus changes
PI >95%
Reversal of A wave
Normal
A wave
A wave
A wave
https://obgynkey.com/venous-doppler-sonography/
A wave
TRUFFLE outcomes by inclusion gestation
Lees et al Lancet 2015 http://dx.doi.org/10.1016/S0140-6736(14)62049-3
TRUFFLE 2 year outcomes
Early Onset FGR Survival (STRIDER UK)
57 Sharp et al. EurJObGyRepBio Oct 2019
• Admit for assessment if viable - tertiary centre (EFW>500g)• Daily cCTG• Fetal movement monitoring• 2-3 x weekly umbilical a Doppler (PI)• Venous Doppler studies• Maternal health → preeclampsia common
Management of early-onset SGA <32w AREDV (1-2% SGA)
• 26-31 weeks (viable EFW >500g)
• deliver based on abnormal DV a-wave or cCTG (TRUFFLE)
• AEDV deliver by 32-34 wks after steroids
• REDV deliver by 30-32 wks after steroids
• Deliver by CS
Early-onset SGA <32w - Delivery
• Late-onset SGA most common (~85%)• Risk factor identification and serial monitoring• Main-stay of management is serial growth scans with detailed
Doppler studies (UtA, MCA, CPR)• Optimum gestation for delivery is ~38 wks or 40 wks if low risk
• Early-onset SGA uncommon (~15%)• Close monitoring and delivery on cCTG or DV a wave• AREDV deliver 30-34 weeks after steroids• Deliver by CS
Summary
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