What should you know about dating scan when?

The purpose is to estimate how far the pregnancy has progressed and to check early development and location. The best appointment time depends on the date of your last period, cycle pattern and whether there is a reason to assess the pregnancy sooner. A scan performed very early may not show every feature clearly, so your clinician may suggest another scan when the findings do not answer the clinical question.

The service may offer the scan as part of routine antenatal care or arrange it because dates are uncertain. It is not the same as a nuchal translucency scan, which assesses a different stage and purpose.

Contact your maternity provider or pregnancy clinic to ask when they want the scan booked. Have the first day of your last period, typical cycle length, fertility treatment information and relevant medical history available. Follow the service's instructions about food, fluids and bladder preparation, since these vary by scan type.

Plan enough time for an explanation after the examination. Ask how the estimated due date will be recorded, whether you need a follow-up appointment and who to contact with questions.

Seek urgent medical advice for vaginal bleeding with significant pain, severe or one-sided abdominal pain, shoulder-tip pain, fainting, severe dizziness or feeling suddenly very unwell. These symptoms require assessment on their own; the date of a planned scan should not delay care.

Ask when your scan should be booked, whether an internal scan may be offered, how the result will affect your due date, when you will hear the findings and what to do if symptoms develop before the appointment.