We were pleased that the editors gave prominence to the article on acute fatty liver of pregnancy (AFLP) in their Digest in the July 2008 issue of Gut, but wish to point out that while Cardiff and Swansea are both cities in Wales, they are distinct. The diagnostic criteria under discussion emanate from Swansea, 40 miles to the west of the principality’s capital.

We welcome the study of AFLP in the UK by Knight et al (Gut 2008;57:951–6) and congratulate the authors. We were pleased that the diagnostic criteria we proposed (Swansea criteria)1 have been independently validated. We wish to make the following comments.

Their study was entitled prospective but was in effect a recent retrospective survey and should not be used to provide an accurate assessment of incidence. Case acquisition was …