What is a Dating Scan (8–22 Weeks)?

A Dating Scan is an early pregnancy ultrasound carried out between 8 and 22 weeks of gestation to accurately determine how far along the pregnancy is. It measures the baby’s size and development to calculate the estimated due date (EDD).

In early pregnancy, the scan typically measures the crown–rump length (CRL), which provides the most accurate dating. Later in the window, additional measurements may be used to confirm gestational age. The scan also confirms the presence of a heartbeat, the number of babies, and whether the pregnancy is developing within the uterus.

Dating scans are a key part of antenatal care and help ensure all future pregnancy assessments and screening tests are timed correctly.

When a Dating Scan is recommended

A Dating Scan is commonly recommended in early pregnancy or when gestational age is uncertain.

You may be advised to have this scan if you:

• Have a positive pregnancy test
• Are unsure of the date of your last menstrual period
• Have irregular menstrual cycles
• Want confirmation of gestational age
• Need accurate dating for antenatal screening
• Have experienced early pregnancy symptoms
• Have had previous pregnancy complications
• Want reassurance in early pregnancy

What the Dating Scan assesses

The scan provides information on:

• Gestational age and estimated due date
• Presence of fetal heartbeat
• Number of embryos (singleton or multiple pregnancy)
• Early fetal development
• Position of the pregnancy within the uterus

Depending on gestation, the scan may be performed transabdominally or transvaginally for optimal image quality.

Benefits of a Dating Scan (8–22 Weeks)

• Accurate estimation of due date
  Provides reliable pregnancy dating.
• Confirms pregnancy viability
  Identifies fetal heartbeat and development.
• Detects multiple pregnancies early
  Important for pregnancy planning.
• Supports correct timing of screening tests
  Ensures anomaly and blood tests are scheduled correctly.
• Provides early reassurance
  Offers peace of mind in early pregnancy.
• Non-invasive and safe
  Uses ultrasound, not radiation.
• Quick and well tolerated
  Usually completed within 15–25 minutes.
• Foundation for ongoing antenatal care
  Guides future pregnancy monitoring.

How the Dating Scan is performed

Home-Based Ultrasound Scans (UK-wide)

• Book your ultrasound appointment online or by phone
• A qualified clinician travels to your home or chosen location
• The scan is performed in the comfort and privacy of your home
• Scan duration varies by examination type (typically 10–30 minutes)
• Findings are explained during or shortly after the scan

Important:
All ultrasound scans are provided as home-visit services only. This service is available UK-wide, allowing you to access diagnostic imaging without attending a clinic.

Understanding your Dating Scan results

Normal findings

Measurements match expected gestational age and a heartbeat is present.

Typical report:

• Pregnancy dated at X weeks with normal development

Adjusted gestational age

Measurements suggest a different gestational age than expected.

Typical report:

• Estimated due date adjusted

This is common and helps improve pregnancy accuracy.

Early pregnancy concerns

In some cases, development may require follow-up.

Typical report:

• Follow-up scan recommended

Results are explained in context and next steps discussed if needed.