What should you know about growth scan for pregnancy?

The sonographer measures parts of the baby, including the head, abdomen and thigh bone, then combines these measurements to estimate growth. The examination can also look at movement, heartbeat, amniotic fluid, placenta location and presentation. An estimate is not the same as a direct weighing, and one scan is interpreted alongside your dates, earlier scans and clinical history.

Your clinician may use blood-flow Doppler measurements when they need more information about placental function or the baby’s circulation. Results can lead to reassurance, another scan, closer monitoring or a discussion about timing and place of birth.

Follow the appointment instructions from the imaging service. Wear clothing that allows access to your abdomen and bring your maternity notes or previous scan details if requested. You usually lie on your back or slightly tilted while gel is placed on the skin. The probe moves over the abdomen and the examination may take longer if the baby’s position makes measurements difficult.

Ask when and how the report will be explained. Keep the appointment even if you feel well, because growth monitoring is planned around your pregnancy history rather than symptoms alone. Do not interpret a single measurement without the clinician’s growth pattern assessment.

A growth scan is a planned assessment, not a replacement for urgent care. Contact your maternity unit promptly for reduced or changed fetal movements, vaginal bleeding, leaking fluid, regular painful contractions, severe abdominal pain, a severe headache with visual symptoms, or sudden swelling with feeling unwell. Use the emergency service if you are seriously unwell or cannot reach your maternity team.

Ask which measurements were taken, how they compare with earlier scans, whether fluid and placental blood flow were assessed, and when you will receive the report. You can also ask what follow-up is recommended and which symptoms should prompt immediate contact.