Fetal growth disorder

Fetal growth disorder

Definition of fetal growth disorder
Is strictly defined as the failure of a fetus to grow according to its genetic potential.
Three percentile thresholds are commonly employed :less than 3rd, less than the 5th, and less than the 10th percentile and the equivalent upper limits used for large infants.
Fetuses outside the given threshold are called small for gestational age(SGA)

Fetal growth restriction would be fetuses whose growth velocity shows down or stops completely because of inadequate oxygen and nutritional supply or utilization .
Normal SGA :no structural anomalies, with normal liquor, normal umbilical artery doppler waveforms and normal growth velocity
Abnormal SGA : those with structural or genetic abnormalities
FGR: those with impaired placental function identified by abnormal UADWs and reduced growth velocity.

aetiology

Maternal factors:
*nutrition
*smoking
*alcohol and drugs of abuse
*maternal therapeutic drug administration
*maternal disease


Fetal factors:
*fetal abnormality
*infection
Placental factors:
*placental mosaicim often associated with chromosomes 16 and 22

prediction

1- history \examination
2- maternal serum screening:alpha- fetoprotein(AFP) oestriol (E3), human placental lactogen (HPL) and human chorionic gonadotrophin (HCG)
3-ultrasound markers: abnormal uterine artery doppler velocimetry(reduced end diastolic flow or notching of woveform

Screening and detection

Clinical assessment
Ultrasound assessment
Liquor volume
Umbilical artery doppler studies :reduced flow in the diastolic component of fetal cardiac cycle in umbilical artery or absent end diastolic flow or the most extreme , reversed end – diastolic flow

Management

1- Prophylaxis and treatment:
Low dose aspirin ,smoking cessation , anti malarial treatment in high- risk areas, protein energy supplementation in poor nourished
2- monitoring the normal SGA fetus:
Conservative management by fetal surveillance is appropriate.assessment should include biometry, UADW analysis and liquor assessment.also use computeriized CTG assessment is superior to conventional CTG


Monitoring the growth –restricted fetus
Management options are limited to timely delivery.
If a diagnosis of FGR IS MADE AFTER 34 weeks gestation,delivery is indicated.
Under 34 weeks , steroids should be administered, there is no clear evidence to guide management. Between 28 and 34 weeks,the presence of REDF should prompt delivery
Long term follow up of fetuses demonstrating increased middle cerebral artery flow

Examination of fetal venous systems:increased pulsatility in the umbillical veins and vena cava and reversed flow during atrial contraction in ductus venous

Labour and delivery

GRF are at high risk of intrapartum hypoxia and acidaemia.
At gestations under 37 weeks, delivery by caesarean section is usually the best option.
It would appear that fetuses with normal UADW tolerate labour well, making induction of labour a possibility at more advanced gestations
Continual electronic fetal monitoring with early recourse to fetal scalp sampling is strongly advisable
Because of the risk of uterine hypertonicity, prostaglandins and oxytocin must be used with great care

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