Fetal growth8th December 2013

Fetal growth

Intrauterine fetal growth abnormality > fetal abnormalities

Failure to detect --> neonatal morbidity to IUD

Causes:

Utero placental insufficiency

Chromosomal abnormalities

Fetal abnormality

Fetal infection

IUGR

Features of IUGR on ultrasound:

Reduction in growth velocity

Oligohydramnios

Reduced bio-physical profile

Mild cardiomegaly

Hyperechoic bowel and dilatation

Doppler changes

IUGR

IUGR

DEFINITION:

Birth weight <10th centile for gestational age

Problem:

10% normal also included

The majority of fetuses with uteroplacental insufficiency has measurement above 10th centile

IUGR

Solution:

Better to use customised growth chart

Based on mother's weight, parity, birth wt of previous children

E.g. A fetus that weighs 2.9kg at 39 w is probably growth restricted if mother is 6ft tall, weighs 65kg and has a previous child weighing 4.2kg at birth

IUGR

Growth velocity:

A fetus with falling growth velocity that is crossing centile lines

Correct pregnancy dating is essential

IUGR

Symmetrical growth restriction:

Equivalent reduction in growth velocity of both fetal head circumference & abd circumference (H:A ratio)

Distinguishing between normal and abnormal pregnancy

Constitutionally small fetus- growth velocity continues on same centile

Pathologically small fetuses:

Growth velocity continues to fall and cross lower centiles

IUGR

Asymmetrical growth restriction:

Differential reduction in growth velocities of the fetal head to abd circumference = uteroplacental insufficiency

Biophysical profile

< 6 - abnormal

7-8 - suspicious