McGuinn v Lewisham And Greenwich NHS Trust

In clinical negligence, compliance with a responsible body of medical opinion does not conclude the inquiry. The court must assess whether that opinion has a logical and rational basis, taking account of the evidence as a whole.

When assessing antenatal evidence of possible microcephaly, the relevant question may be whether the fetus is at risk of the condition, rather than whether a formal diagnosis is already justified. A head circumference below the 3rd centile and a declining head-growth velocity may together provide sufficient evidence to require referral or earlier reassessment. A normal head-to-abdominal circumference ratio is relevant but is not determinative. Borderline ventricular measurements may also require assessment in the context of a markedly small head.

The claimant alleged that the defendant’s clinicians negligently failed to recognise during her pregnancy that the fetus was at risk of microcephaly and failed to refer her for tertiary-level investigation and assessment. Her daughter was subsequently born profoundly disabled and was later diagnosed with microcephaly.

Causation and other issues remained in dispute. The immediate issue was whether the claimant had established, on the balance of probabilities, a breach of duty in relation to the interpretation of the antenatal ultrasound scans and the decisions taken after the fifth and seventh scans.

1. The court applied the principles in Bolam v Friern Hospital Management Committee [1957] 1 WLR 583, as qualified by Bolitho v City and Hackney Health Authority [1998] AC 232. Expert opinion deserved substantial weight, but the court retained responsibility for deciding negligence and had to be satisfied that the opinion relied upon had a logical and rational basis.

2. The assessment had to address the whole evidential picture. Relevant considerations included the fetal head circumference, its growth velocity, the comparative growth of other measurements, the ventricular measurements, and the clinical context. The court accepted the analytical guidance in C v North Cumbria University Hospitals NHS Trust [2014] EWHC 61, including the need to test expert opinion against the evidence and its internal consistency.

3. A formal diagnosis of microcephaly was not required before a duty arose to investigate the risk. A head circumference below the 3rd centile was at least evidence that the fetus was at risk. The declining head-growth velocity shown by the scans was an additional significant factor because normal head growth should ordinarily continue along the same centile during gestation.

4. The HC/AC ratio was relevant but could not be treated as determinative. A normal or high ratio did not exclude microcephaly, particularly where other evidence indicated a small and progressively smaller head. At the seventh scan, an atrial width approaching 10mm also had to be assessed in the context of the markedly small head. The available Vp/H ratio was potentially relevant to that assessment.

5. The fifth scan provided sufficient evidence that the fetus was at risk of microcephaly. The defendant should therefore either have referred the claimant for tertiary-level investigation and assessment or arranged a further scan at about 32 weeks, rather than waiting until 34 weeks. The seventh scan provided still stronger evidence and required referral for further tertiary-level investigation and assessment. The care at both scans reflected inappropriately low standards of clinical care. The judgment determined breach only; causation and other issues remained unresolved.