Montgomery (Appellant) v Lanarkshire Health Board (Respondent) (Scotland)

dystocia. It is agreed that that risk was 9-10% in the case of diabetic mothers.
Unsurprisingly, Dr McLellan accepted that this was a high risk. But, despite
the risk, she said that her practice was not to spend a lot of time, or indeed
any time at all, discussing potential risks of shoulder dystocia. She explained
that this was because, in her estimation, the risk of a grave problem for the
baby resulting from shoulder dystocia was very small. She considered,
therefore, that if the condition was mentioned, “most women will actually
say, ‘I’d rather have a caesarean section’”. She went on to say that “if you
were to mention shoulder dystocia to every [diabetic] patient, if you were to
mention to any mother who faces labour that there is a very small risk of the
baby dying in labour, then everyone would ask for a caesarean section, and
it’s not in the maternal interests for women to have caesarean sections”.
14. During her fortnightly attendances at the clinic, Mrs Montgomery underwent
ultrasound examinations to assess foetal size and growth. The final
ultrasound examination was on 15 September 1999, at 36 weeks gestation.
Dr McLellan decided that Mrs Montgomery should not have a further
ultrasound examination at 38 weeks, because she felt that Mrs Montgomery
was becoming anxious as a result of the information revealed by the scans
about the size of her baby. That sense of anxiety related to her ability to
deliver the baby vaginally.
15. Based on the 36 weeks ultrasound, Dr McLellan estimated that the foetal
weight at birth would be 3.9 kilograms. She made that estimate on the
assumption that the baby would be born at 38 weeks. This is important
because Dr McLellan gave evidence that, if she had thought that the baby’s
weight was likely to be greater than 4 kilograms, she would have offered Mrs
Montgomery a caesarean section. In keeping with general practice Dr
McLellan would customarily offer a caesarean section to diabetic mothers
where the estimated birth weight is 4.5 kilograms. She decided to reduce that
threshold to 4 kilograms in Mrs Montgomery’s case because of her small
stature.
16. As Dr McLellan was aware, estimating birth weight by ultrasound has a
margin of error of plus or minus 10%. But she decided to leave this out of
account, stating that “if you do that you would be sectioning virtually all
diabetics”. By the time of the 36-week examination, Dr McLellan had already
made arrangements for Mrs Montgomery’s labour to be induced at 38 weeks
and 5 days. She accepted in evidence that she should have estimated the
baby’s birth weight as at 38 weeks and 5 days, rather than 38 weeks, and that
the estimated birth weight would then have been over 4 kilograms which was,
of course, beyond the threshold that she herself had set. In the event, the baby
was born on the planned date and weighed 4.25 kilograms.
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