At what gestational age is the foetal anomaly scan typically performed?

The fetal anomaly scan is typically performed between 18 and 20 weeks of gestation. This timing is crucial because it allows for the visualization of the developing fetus, providing an opportunity to identify structural anomalies that may not be detectable in earlier scans. By this stage, the majority of fetal organs and systems are sufficiently developed, making it possible to assess them accurately.

This scan is part of routine antenatal care and focuses on checking for any physical abnormalities in the fetus, ensuring that any potential issues can be addressed as early as possible. While earlier scans at 12-14 weeks are useful for initial assessments, including nuchal translucency for Down syndrome screening, they do not provide the same detailed anatomical information that the anomaly scan does. Scans conducted later than 20 weeks may limit surgical or therapeutic options, should any anomalies be found, so the standard practice is to conduct the anomaly scan within that 18-20 week window.