Hello and welcome to the zero to finals podcast.

My name is Tom and in this episode I'm going to be talking to you about small for gestational age.

And you can find written notes on this topic at zero to finals.com slash SGA

or in the antenatal care section of the zero to finals, obstetrics and gynecology book.

So let's get straight into it.

Small for gestational age is defined as a fetus that measures below the 10th centile for their gestational age.

Two measurements on ultrasound are used to assess the fetal size,

the estimated fetal weight and the fetal abdominal circumference.

Customized growth charts are used to assess the size of the fetus,

and these are based on the

mother's ethnic group, weight, height, and parity, how many previous pregnancies she's had.

Severe, small for gestational age is when the fetus is below the third centile for their gestational age.

Low birth weight is defined as a birth weight of less than 2,500 grams or 2.5 kilograms.

Let's talk about the causes of small for gestational age.

The causes of a fetus being small for their gestational age can be divided into two categories.

Constitutionally small, which means they match the mother and others in the family

and are growing appropriately on the growth chart,

and fetal growth restriction, or FGR, which is also known as

intrauterine growth restriction, or IUGR. Fetal growth restriction is when there is a small fetus,

or a fetus that is not growing as expected, which is due to a pathology reducing the amount

of nutrients and oxygen that are being delivered to the fetus through the placenta.

A tom tip for you, it's important to note the difference between small for gestational age

...