XXX v King's College Hospital NHS Foundation Trust

A sonographer undertaking a 20-week fetal anomaly scan must be judged by the standards of a reasonably competent and well-informed sonographer at the time of the scan. Where contemporary practice requires separate identification of the left and right ventricular outflow tracts, the scan must be conducted with sufficient care to identify whether both are genuinely present. A continuous sweep from the four-chamber view towards the fetal head was the appropriate technique. Viewing structures at different angles and times created a risk of mistaking one vessel for two, particularly where unusual anatomy produced a mimicking image. General statistics about missed cardiac abnormalities did not assist without evidence focused on the particular anomaly and a competently performed scan. Breach and causation were established on the balance of probabilities.

This was a wrongful birth claim arising from a fetal anomaly scan performed at 20 weeks’ gestation. The claimant mother alleged that the defendant NHS Trust’s sonographer negligently failed to identify an abnormal cardiac structure indicating the need for further investigation and amniocentesis. The child was subsequently born with truncus arteriosus, a large ventricular septal defect and a 22q11.2 deletion. The central issues were whether the scan fell below the standards applicable in July 2011 and whether, if the abnormality had been identified, the mother would probably have terminated the pregnancy.

1. The applicable standard was that of the reasonably competent and well-informed sonographer, assessed by reference to contemporary standards in July 2011. By that time, reasonable ultrasound practice required identification of a normal left ventricular outflow tract and right ventricular outflow tract as separate features before reporting the scan as normal.

2. The appropriate technique was the sweep technique: starting with the four-chamber view and moving towards the fetal head to obtain the outflow tract views sequentially. The relevant structures should be seen separately within the same timeframe. A technique involving different planes and substantially different times risked causing one anatomical structure to mimic two separate outflow tracts.

3. The child’s rare cardiac anatomy could potentially produce a mimicking image. Nevertheless, on the expert evidence preferred by the court, a properly executed sweep would have revealed that there were not two separate outflow tracts. The sonographer most likely moved inadvertently into a different plane and mistook the same vessel, viewed from another angle, for a separate tract. The scan therefore fell below the required standard.

4. General detection statistics did not establish that a properly conducted scan directed to identifying separate outflow tracts would commonly miss this anomaly. The evidence was insufficiently specific and did not provide a valid cohort for assessing non-negligent failure in the circumstances of this case.

5. On the balance of probabilities, the claimant mother would have terminated the pregnancy if informed of the cardiac defect and the possible consequences of the chromosomal abnormality. Judgment was entered for the claimants, with damages to be assessed.