Dr. Mariam Al-Bloushi Consultant Fetomaternal Women s ... · 1. In case of maternal clinical...

Dr. Mariam Al-Bloushi

Consultant FetomaternalWomen’s Hospital Hamad Medical Corporation

DR. MARIAM ALBLOUSHI

I have no financial interests or relationship to disclose


Fetal Growth Restriction

Definition and prevalence

Aetiology – risk factors

Screening

Diagnosis

Monitoring

Timing of Delivery

Outline of Presentation


Is IUGR = SGA

Is SGA a pathological condition ?

? ? ? ?DR. MARIAM ALBLOUSHI

Is a major problem

in perinatal medicine


Fetal growth restriction remains a major cause of perinatal morbidity and mortality in modern obstetric practice.

Placental insufficiency is the most common association, but is often a diagnosis of exclusion.

Currently, no treatment can ameliorate or reverse established growth restriction.

However the potentially exciting use of maternal gene therapy is being investigated (USOG March 2016)


The clinical significance of FGR relates to the dramatically increased perinatal mortality:

with mortality being eight times higher when weight is below the 10th percentile .

nearly 20 times higher when weight is below the 3rd centile.

When associated with prematurity, outcomes are even worse with

survival figures of less than 50% for gestations less than 28 weeks.


Perinatal Mortality and Birthweight


increased mortality, both short- and long-term morbidity are increased in the growth-restricted fetus,

Short term neonatal complications :

birth hypoxia.

when combined with prematurity, increased risks of respiratory distress syndrome.

necrotising enterocolitis.

retinopathy of prematurity.

infection .

hypoglycaemia.


long-term metabolic consequences growth restriction:

increased risks of insulin resistance. cardiovascular complications. psychiatric disorders.


As a result of these effects on perinatal morbidity and mortality, accurate diagnosis and management of the

growth-restricted fetus remains one of the most important

goals of antenatal care


Fetal “overgrowth”

Fetal growth restriction


Most commonly used Birth weight below a defined centile for gestation, gender and race3rd or 5th or 10th

Fetal growth restriction (FGR, also called intrauterine growth restriction [IUGR]) is the term used to designate a fetus that has not reached its growth potential because of genetic or environmental factors.

Definition


Failure of the baby to achieve its predetermined genetic growth potential

Small for Gestational age (SGA) – bwt<10th centile

Fetal growth restriction [FGR] is not synonymous

with SGA SOME, but not all [FGR] are SGA while 50-70% of SGA fetuses are constitutionally small .


It may be caused by fetal, placental, or maternal factors, with significant overlap among these entities.

This term should not be used to describe a constitutionally small, but otherwise healthy fetus.


Normal Growth Patters of Fetuses


Constitutional – 50-70% of casesPathological – FGR

Non-placental mediated Structural Chromosomal In-born errors of metabolism Fetal infections

Placental mediated Essential hypertension Pre-eclampsia Autoimmune disease Thrombophilia Renal disease Diabetes


Causes of FGR

Complex interaction

Fetal Growth

Restriction

Fetal•Chromosomal (T13,18,21 etc)

•Mendelian single gene disorders

•Congenital malformations

•Other syndromes (e.g. Cornelia de Lange)

•Inborn errors of metabolism

Extrinsic•Cigarette smoking

•Alcohol

•Substance abuse (e.g.cocaine, marijuana)

•Viral infections

Maternal•Hypertensive disorders

•Antiphospholipid syndrome

•Thrombophilias

•Hypermomocysteinema

•Low weight, severe anaemia,

Placental factors•Confined placental mosaicism

•Abnormal placentation

•Uterine abnormality

•Chronic placental abruption

Idiopathic


Chromosomal abnormalities are present in

8% of those morphologically normal

30 - 40% of those with associated malformations

Common abnormalities – T13, 18 & 21

Others – Triplody and other trisomies

Monosomies (45XO)

Confined placental mosaicism – most (mitosis or somatic errors) arise from non-disjunction post fertilisation.

Non-chromosomal cases may be syndromes and other genetic abnormalities

Prevalence of Genetic abnormalities associated with FGR


Risk factors for Small for Gestational Age

RCOG Green-Top Guideline No 31, 2013

Risk factor Odds Ratio

Maternal Risk FactorsAge >40 years 3.2Smoker > 11 cigarettes/day 2.21Cocaine use 3.23Daily vigorous exercise 3.23

Previous HistoryPrevious SGA 3.9Previous SB (unexplained) 6.4

Past Medical HistoryMaternal SGA 2.64Chronic hypertension 2.5Diabetes and vascular disease 6.0Renal Disease 5.3Antiphospholipid syndrome 6.22

Paternal Medical HistoryPaternal SGA 3.47


Risk factors for Small for Gestational AgeRCOG Green-Top Guideline No 31, 2013

Risk factor Odds Ratio

Current Pregnancy

Heavy bleeding similar to menses 2.6

Echogenic bowel 2.3

Pre-eclampsia 2.26

PIH – severe 2.5

Unexplained APH 5.6

Low maternal weight gain 4.9

Low PAPP-A (<0.4MoM) 2.6


Screening for FGR

Identification of risk factors

History

Physical examination – identifies maternal disease/complex pregnancies

Ultrasound Doppler velocimetry

Uterine artery

Biochemistry

αFP (AFP) (>2.5MoM) – not now considered important??

βhCG (>3.0 MoM) ? relevance

PAPP-A (<0.4MoM)


Radiological Screening

Uterine Artery – only clinical useful screening tool available today

Why?


UA Doppler at 20-24 week has a moderate predictive value for severly SGA fetus.

Abnormal uterine artery Doppler PI>95TH

centile or notching.

Serial ultrasound measurement of fetal size

& assessment of wellbeing with UA Doppler

at 26-28 week of pregnancy.

Normal uterine artery Doppler


Specific pregnancy complications:

1- APH

2- Hypertension

However they should be offered a scan for fetal size & UmA Doppler during 3rd trimester.


Diagnosis of FGR

Clinical Examination – SFH at each visit from 24 weeks, plotted on customised population-based charts –as this may improve prediction (not diagnosis).

□ Will identify ~30% of cases.

□ Inaccurate in women with BMI >35, fibroids,

polyhydramnios.

Serial USS biometry (AC & HC) every 2-3 wks combined with SFH – 67% of cases

Routine AC measurement in the 3rd trimester does not reduce risk of neonate with FGR


AFI/SDVP/Dopplers – not used for diagnosis

IUGR MANAGEMENT

A three step approach:

1. Recognition of IUGR.

2. Identification of etiology.

3. Monitoring and timing of delivery


After the introduction of fetal ultrasonic biometry it became possible to move to a

prenatal recognition.


http://www.fetalmaternal.org/images/frightened fetus.jpg

http://www.fetalmaternal.org/images/frightened fetus.jpg

http://grandegraphics.crosswinds.net/images/health/patients/Fetus.gif

http://grandegraphics.crosswinds.net/images/health/patients/Fetus.gif

WHICH BIOMETRIC PARAMETER?

1. Estimated fetal weight.

2. Abdominal circumference.

They should be at least 2-3 week apart to

minimise false –positive rates for diagnosing

FGR.


Fetal Biometry

Biparietal Diameter and Head Circumference

T

T

CSP

AntPost

BPD

OFD

Atria

Frontal Horn

Frontal Horn

Insula

*

* 3° Ventricle


Fetal Biometry

Abdominal Circumference

Stomach

Spine

Umbilical

Vein

Aorta

IVC

Left portal vein

Left

Right

Ant Post


Fetal Biometry

Femur Length


CRITERIA FOR IUGR RECOGNTION BY US BIOMETRY

To know exactly the GA.

To compare the biometry with growth charts (customized)

To repeat the scan at >2 weeks distance.


Clinically suspected FGR

Ultrasound scan to confirm diagnosis?

Yes - diagnosis confirmed

Questions

What is the type of FGR?

Any associated aneuploidy or infection?

Is delivery warranted?

When is delivery recommended or appropriate?


What is the type of FGR?

Symmetrical/asymmetrical

Based on Ratio of HC to AC

Reduced AFI/SDVP

Any fetal abnormalities?

Fetal vascular studies – umbilical and middle cerebral

Maternal vascular – uterine artery Dopplers

Co-existing pathology e.g pre-eclampsia


Any associated infection or thrombophilia?

Infection screen – maternal blood and fetal specimens

CMV, Toxoplasmosis

Syphilis in high risk populations

Malaria in high risk populations

Thrombophilia – changes with pregnancy

Undertake these only if indicated


Any associated karyotypicabnormality?

When is karyotyping necessary?

Symmetric FGR (especially <24 wks.) with

Normal AFI

Polyhydramnios

Normal umbilical artery Doppler

Normal uterine artery Doppler

FGR and Structural abnormalities


Monitoring of FGR

Fetal biometry.

Doppler of the fetal arterial circulation.

Doppler of the fetal venous circulation.

Biophysical profilometry.

Fetal kick chart.

Cardiotocography.


Any Interventions to prevent FGR?

Antiplatelet agents – effect size is small though

In women at risk of PE

Started at or before, 16 weeks (maybe started after)

Smoking cessation promotion

No evidence that dietary modification ,progesterone and calcium make improve outcome

Anti-thrombotic therapy – promising but no sufficient evidence yet


Management of IUGR is dependent on the primary etiology of IUGR

1. In case of maternal clinical conditions like preeclampsia it is mainly dependent on the characteristics of the maternal disease.

2. when the etiology is fetal {infection, chromosomal abnormalities & malformations} no management can significantly improve the outcome & sometime it can be considered as a contraindication for aggressive management.


4. Affected by CFH the fetus undergoes changes of many vital function ,so the close monitoring of these changes is the basis of the management .

3. Placental obliterative vasculopathy, the out come can be improved & the management should be based on its careful monitoring.


As the only therapy for CFH is the delivery it is crucial to choose the best timing.

The most commonly used methods are represented by:

- Doppler studies.- CTG.- Amniotic fluid evaluation.- Fetal biophysical profile.


UmA Doppler is the primary surveillance tool in the SGA fetus.

When UmA Doppler flow indices are normal

………… 2 week

UmA Doppler flow indices are abnormal

– P or RI ≥2 SD & delivery is not indicated repeat Doppler twice weekly (i.e. every 2-3 days)

– A&REDF – Repeat Doppler Daily.


Management of FGR

Delivery Timing – when fetal maturity is maximum

Balancing the risks of a hostile intrauterine environment and those of early delivery

Prematurity

Intrauterine asphyxia and death

Neonatal complications

Operative maternal delivery


Timing of delivery

When risk of intrauterine existence exceeds that of extra-uterine existence

This is achieved through monitoring

Timing difficult for FGR between 24-28 weeks

GRIT Trial – (Hornbuckle et al BJOG 2003 2003) no answer


Interventions at the time of delivery

Corticosteroids if:

Delivery contemplated between 24+0 and 35+6 weeks

Magnesium sulphate if <30 weeks may be neuroprotective (Cochrane Review 2016)


Factors influencing the timing of delivery

Gestational age

Neonatal facilities and survival rates for unit

Growth profile

Health of the mother

Indices of fetal health/well being - MONITORING

CTGs

Dopplers – UmA, MCA, Ductus venosus other vessels

Amniotic fluid index/SDVP

Fetal blood gases


Thank you


Dr. Mariam Al-Bloushi Consultant Fetomaternal Women s ... · 1. In case of maternal clinical...

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