If you have a risk factor for foetal growth restriction (FGR), or if your fundal height measurements indicate that your baby may be small, then you will be offered growth scans. When they start depends on your individual needs.
If you are at increased risk of having early onset growth restriction (where baby grows smaller than expected from early pregnancy) then you may be offered monthly or more frequent growth scans starting at 24-26 weeks.
If you are at increased risk of growth restriction, but not of early onset growth restriction, then you may be offered monthly growth scans from 26-28 weeks onwards.
If you have large fibroids or a BMI over 35, or if you develop polyhydramnios (extra amniotic fluid around baby), then you may be offered two growth scans, at 30-32 and 36-38 weeks.
If you are pregnant with twins or triplets, then you will be offered regular growth scans as planned by the obstetric team caring for you.
If your fundal height shows that you may have a small baby, or that your baby’s growth may be slowing, then your care provider (midwife or doctor) may recommend a growth scan to assess this.
Growth scans aim to identify small babies before they are born, as these babies may not cope as well with labour and may need extra monitoring. It is hoped that identifying at-risk babies before they are born may help reduce stillbirth rates.
It is important to know that growth scans can have a large margin of error, around 10-15% – so they can over- or under-estimate baby’s size by quite a bit. Repeat growth scans are recommended to get an idea of baby’s growth over time.
If you report changed foetal movements to your midwife, then they may arrange a growth scan for you within a week, depending on local guidelines.