What should you know about a pregnancy growth scan?

It may assess growth pattern, heartbeat, movement, position, placenta and amniotic fluid, helping your care team decide whether routine care is suitable or closer review is needed.

A sonographer moves gel and a probe over your abdomen to create images. Measurements of the baby's head, abdomen and thigh bone can be used to estimate size. The estimate has limits and is considered with your pregnancy dates, previous scans, blood pressure, symptoms and other clinical information. A result that differs from expectation does not by itself explain the cause; your maternity team may arrange repeat imaging or additional checks.

The scan can also show whether the baby is head-down, although position may change before birth. It is designed for medical assessment, not as a complete guarantee about labour or health after delivery.

Follow the service's instructions about bladder preparation, meals and arrival time, since these differ between appointments. Bring your pregnancy records and note questions about growth, fluid, placenta or delivery planning. Afterward, make sure you know who will explain the report and whether another appointment is needed. Continue your usual maternity care unless your clinician gives different advice.

Call your maternity team promptly about reduced fetal movement, vaginal bleeding, fluid leaking from the vagina, painful regular contractions, severe abdominal pain, severe headache or visual disturbance. Emergency help is appropriate for heavy bleeding, collapse, breathing difficulty or feeling dangerously unwell. A booked scan does not replace assessment of a new symptom.

Ask which measurements are being followed, whether blood flow or fluid needs extra attention, how the estimated size affects planning, and when you should expect the report. Clarify the exact contact route for concerns about movement or bleeding.