IUGR pdf - ملال محمد

I. U .G.R.

Significance

I.U.G.R. is a major cause of neonatal

morbidity & mortality.

Certain adult diseases including

hypertension & diabetes are related to
I.U.G.R.

Definition

I.U.G.R. Is defined as failure of the fetus to acheive

its genetic growth potential .

S.G.A.: fetus or neonate is below a certain defined

centile of weight or size for a particular

gestational age ( below 3

or 5

centile ) ,and

SGA are constitutionally small due to normal

genetic influences.

While IUGR indicates that a particular pathological

process is operating to modify the intrinsic growth

potential of the fetus by reducing its growth rate .

Recent definition of IUGR

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Early‐onset growth restriction < 32 weeks.

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AC or EFW <3rd centile or absent EDF in the
umbilical artery

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1) AC/EFW <10th centile combined with

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2) Uterine artery PI >95th centile and/or

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3) Umbilical artery PI >95th centile

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Late‐onset growth restriction > 32 weeks.

Incidence of IUGR

3-5%

Aetiology

1-Reduced fetal growth potential

(intrinsic)

A-chromosome defect e.g trisomy 18 ,

triploidy.

B-single gene defects e.g seckel’s synd.
C-structional abn. e.g renal agenesis
D-infection e.g TORCH

Aetiology

2-Reduced fetal growth support (extrinsic)

A- maternal factors

1.Undernutrition e.g poverty , eating

disorders .

2.Maternal hypoxia e.g altitude , cyanotic

heart disease .

3.drugs:cigarette smoking , alcohol, cocaine ,

warfarin, phenytoin, cytotoxic drugs.

1-Reduced utero –placental perfusion: e.g

inadequate trophoblast invasion ( e.g HT, PET

),
Antiphospholipid syn. ,D.M with vascular

lesions advanced ), sickle cell disease ,

multiple pregnancy .

2-Reduced feto – placental

pefrusion

A-single umbelical artery.
B- twin – twin trasfusion syn.

Complications

Antepartum complications

1- stillbirth (fetal death in IUGR more

frequent after 35 weeks of gestation ) .

2- oligohydramnios ( in severe IUGR due

to vasoconstriction in the fetal kidney
results in impaired urine production ).

3- Antepartum fetal distress.

Intrapartum complications

Intrapartum fetal hypoxia & acidosis
Increased incidence of c/s
Due to marked depletion of energy stores in

the liver & subcutaneous tissues .

Neonatal complications

1- Related to perinatal asphyxia &

acidosis :

Persistent fetal circulation , meconium

aspiration syn. ,hypoxic – ischemic

encephalopathy .

2- Metabolic alterations : hypoglycemia ,

hypocalcemia , hyperviscosity

syn. ,hyperbilirubinemia, hypothermia .

Neon

atal complications

3- Related to the specific cause of IUGR
Infection , cong. Malformations ,

chromosomal abn.

Classifications

Intrinsic IUGR (symmetric

) : due to fetal

condition e.g infection , chromosomal abn.

2-Extrinsic (Asymmetric)

: due to element

outside fetus ( placental condition or maternal
disease ) .

3- Combined IUGR

(both intrinsic & extrinsic

factors ).

4- Idiopathic IUGR.

Comparison of symmetric &

Asymm. IUGR

Symmetric

Asymmetric

1-symmetrically small 1-head larger than

abdomen

2-Normal ponderal index   2-Low ponderal
     PI=8 ±2                          index   PI<7
3-Normal head/abd.          3-Elevated head /
& femur /abd. Ratio            abd.& femur/abd.
ratio.

4-Genetic disease , infection . 4-placental
vascular
                                              insuffiency
5-complicated neonatal           5-benign
Course                               neonatal course
Poor prognosis

Diagnosis

1-clinical diagnosis:
A-medical & obs. History
Chronic HT , PET, Ch. Renal disease, twin
pregnancy, advanced DM, prior history of
delivery of IUGR .
B-Decrease maternal weight gain during
pregnancy ( insensitive sign ).
C- Uterine fundal height :is most common
method used .

Symphysis–fundal height

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symphysis–fundal height (SFH), the distance

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from the symphysis pubis to the uterine fundus, is
measured

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at each midwife or antenatal attendance from 24
weeks’ gestation.

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As a guide, the SFH in centimetres is equal to the

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number of weeks of gestation plus or minus 2 cm.

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After 36 weeks, the acceptable difference increases
to 3 cm.

Diagnosis

2- u/s biometry
BPD, head circumference, abd.

Circumference,femur length.

Amount of liquor :oligohydramnios.

Diagnosis

3- Doppler waveform analysis
During pregnancy:umbilical & uterine

artery have low resistance & low S/D
ratio .

In IUGR : decreased or absent diastolic

flow or reversed diastolic blood flow.

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the concept of ‘brainsparing’

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involves redistribution of blood by dilatation of the

cerebral vessels, thus increasing substrate and oxygen

supply to the brain, in response to fetal

chemoreceptor or baroreceptor stimulation.

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results in

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a reduction in fetal MCA PI.

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this is associated with increasing impedance in the

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umbilical artery.

Cerebroplacental ratio

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By using the ratio of MCA to umbilical
artery Doppler PI –

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the cerebroplacental ratio.

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Reduced CPR in IUGR

Diagnosis

4- Amniocentesis
Every week after 36 weeks for fetal lung

maturation.

5- Cordocentesis
Umbilical cord blood sampling (rarely

indicated ).

For rapid determination of fetal karyotype

when chromosomal defect is suspected .

(a) Normal uterine artery Doppler
waveforms

(b) abnormal uterine artery Doppler
waveforms. The waveform in (b) has reduced diastolic
flow velocities and an early diastolic notch.

Umbilical artery Doppler waveforms: (a) normal; (b)
absent end‐diastolic flow; (c) reversed end‐diastolic
flow.

Management

1.At present no accepted treatment available

for growth restriction related to placental

dysfunction .

2.Obvious adverse factors :smoking, alcohol

&drug abuse should be stopped.

3.Health of the mother should be maximized
(optimal control of DM, thyroid dysfunction,

HT ).

4.When growth restriction is severe & the

fetus is considered too immature to be

delivered :bed rest in hospital is advised to

to maximize placental blood flow.
5. Antepartum assesment of fetal wellbeing
By fetal biometry every 2 weeks ,
Doppler u/s & fetal cardiotocography (NST).
Absence of blood flow in the umbilical artery

or reversed flow (i.e back towards the heart
requires delivery in the near future or when
NST is non- reactive .

NST daily in severe cases .
Less severe cases : NST weekly or twice

weekly .

No effective drug therapy for IUGR has yet been

found .Small studies suggested aspirin , nitric
oxide donors , or anti- oxidants may be helpful
in some cases .

These drugs may act by reducing platelet

activation in the utero- placental circulation , or
may be acting directly as vasodilators.

Labour

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Because of the high incidence of hypoxia &

acidosis , labour & delivery should be

aggresively managed .

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Continuous fetal heart monitoring ( scalp

monitoring electrode & uterine pressure

catheter .

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Shorten the second stage of labour by

forceps .

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Epidural anesthesia is the method of choice

for pain relieve .

Labour

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Pediatrician should be present at delivery .

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Placenta need careful examination by
pathologist :for cause of IUGR .

Prognosis

1.The length of the insult seems to be more

important than its severity in terms of both

somatic growth & neurologic development .so

the earlier in pregnancy that IUGR is detected

the greater the probability of developmental

problems later in life .

2. The probability of developmental problems is

lower when there is catch – up growth during

the first 6 months of life .

Prognosis

3. The worst prognosis is for babies with

IUGR caused by congenital infections or
chromosomal defects .

4. A link between IUGR & the adult

incidence of both hypertension & DM
has now been established .

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Thank you