Growth scan at 24 weeks: what to know

A growth scan at 24 weeks checks your baby's size, growth pattern, position, movements, fluid around the baby, and placental blood flow when needed. It uses ultrasound and is often arranged when your maternity team wants a closer look at growth or another pregnancy finding. The scan gives an estimate rather than a direct weighing of the baby, so your clinician interprets it alongside your dates, examination, symptoms, and earlier scans.

The sonographer measures parts of the baby's body, such as the head, abdomen, and thigh bone, to estimate size and assess the growth pattern. They may review the baby's heartbeat, activity, position, and the amount of amniotic fluid. Doppler assessment can examine blood flow through vessels linked with the placenta when this is clinically useful. The appointment may also look at the placenta and cervix, depending on the reason for the scan and the local service.

A result that differs from the expected range does not by itself explain why. It may lead to a repeat scan, closer monitoring, or other checks. A single measurement can be affected by pregnancy dating, the baby's position, and the limits of ultrasound estimation.

Follow the instructions from the imaging or maternity team about food, drink, and bladder preparation; these can vary by service and by the type of scan. Wear clothing that allows easy access to your abdomen. During the appointment, you usually lie back while gel is placed on your skin and a transducer is moved over your abdomen. The examination may take longer if the baby is facing away or moving into a difficult position.

Bring your pregnancy records if requested and tell the team about previous scan findings, bleeding, pain, fluid leakage, or changes in your baby's movements. Ask when and how you will receive the report, and whether a follow-up appointment is already planned.

Do not wait for a planned growth scan if you have vaginal bleeding, leaking fluid, severe or persistent abdominal pain, regular tightening, a severe headache with vision changes, sudden swelling, fever, or you feel unwell. Contact your maternity unit or urgent medical service promptly. If your baby's movements are less than usual or have changed noticeably, contact your maternity team immediately for advice rather than relying on the scan appointment.

A growth scan is a scheduled assessment, not a substitute for urgent review of new symptoms. The maternity team can tell you where to go based on your pregnancy and local arrangements.

You could ask: Why has this scan been recommended? How are the measurements compared with my pregnancy dates? Was the fluid level, placenta, or blood flow reassuring? Will I need another scan or monitoring? When should I expect the report, and who will explain it to me?