Lillywhite & Anor v University College London Hospitals NHS Trust

A medical professional is not negligent merely because another practitioner would have reached a different diagnosis. The question is whether the defendant failed to exercise the ordinary skill of the relevant specialty, assessed in its factual and professional context. A body of expert opinion does not automatically protect a defendant; the court must be satisfied that the opinion has a logical and defensible basis. In a difficult diagnostic case, the court must assess the quality of the examination, the information reasonably available at the time, the possibility of misleading clinical or technical features, and the competing risks of false positive and false negative diagnoses.

The claimants sought damages arising from the birth of their severely disabled daughter, alleging that an ultrasound scan at about 18 weeks’ gestation negligently failed to detect semilobar holoprosencephaly. The defendant was sued as the employer of the consultant who performed the relevant tertiary-referral scan.

The court considered whether the scan was carried out with the skill and care expected of a consultant sonologist at a tertiary referral centre. It also considered whether the claimants would have accepted termination had a serious abnormality been diagnosed. Liability, rather than damages, was tried.

1. Claim dismissed. The claimants established that they would have chosen termination if holoprosencephaly or another serious abnormality had been diagnosed. They did not establish negligent diagnosis.
2. The applicable standard was the ordinary skill of the defendant’s specialty, namely that expected of a consultant sonologist at a tertiary referral centre. The scan required particular care because an earlier examination had failed to visualise important structures and the purpose of the referral was to resolve that concern.
3. The principles stated in Penney, Palmer and Cannon v East Kent Health Authority [2000] PNLR 323, including the principles derived from Hunter v Hanley [1955] SLT 213, Maynard v West Midlands Regional Health Authority [1984] 1 WLR 634 and Bolitho v City and Hackney Health Authority [1998] AC 232, were applied. Genuine professional disagreement does not itself establish negligence, but expert opinion must have a logical basis.
4. The evidence showed that the consultant had conducted a careful and detailed examination. Three skilled sonologists had been persuaded by echoes which mimicked absent cerebral structures. The evidence identified possible mimics for the cavum septum and anterior ventricular horns, while the explanation for the anterior falx remained uncertain.
5. The court was not satisfied, on the balance of probabilities, that a careful consultant would necessarily have recognised the apparent echoes as mimics. The unusual presentation, the limitations of ultrasound in 1991, the absence of other commonly associated abnormalities, and the possibility that the relevant structures might not be observable meant that negligence was not proved.