Pregnancy

FETAL GROWTH AND WELL-BEING SCAN (>24 WEEKS)

The assessment of fetal well-being from 24 weeks involves the study of several different parameters.

Fetal growth is determined by measurement of the head, abdomen and femur length. It is then possible to estimate fetal weight which may be compared with the expected growth for that gestation.

Measurement of the liquor volume is a good indicator of pregnancy complications including diabetes and placental insufficiency.

The observation of fetal movements and fetal breathing movements are also made and are indicators of fetal wellbeing.

Colour flow Doppler to assess fetal blood flow and maternal blood flow in the uterine arteries is a sensitive marker of the health of the pregnancy. In some cases, detailed assessment of the fetal blood vessels may be recommended by your consultant.

The position of the placenta in relation to the cervix is checked to exclude a placenta praevia. If the placenta was found to be “low lying” at your 20 week scan, your consultant will usually advise such a scan.

Indications for serial scans:

• Maternal disease such as diabetes, hypertension or cardiac disease
• Multiple pregnancy
• Previous small babies or complicated pregnancy
• Suspected breech presentation
• Clinically suspected reduced or increased fetal growth
• Clinically suspected reduced or increased liquor volume
• Poor flow in the uterine arteries detected on the 20-23 week scan

The growth scan at 28-34 weeks is often the best time for obtaining 3D and 4D views of the baby.

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