Foetus acardius amorphus.

drug retention at a time when her dietary intake was below the level of 400 ,zg folic acid-the level shown by Kahn to be necessary to counteract co-trimoxazole antagonism of folic acid. In addition to these factors, however, it may be expected that her folic acid consumption was much higher than normal as she had evidence of a significant haemolytic anaemia. It is well known that a haemolytic anaemia may cause megaloblastic anaemia due to depletion of body folic acid storesChanarin, Dacie & Mollin (1959). On the other hand, Clarkson et al. (1970) did not comment on megaloblastic anaemia in his cases with the haemolytic uraemic syndrome. Finally, during the later stages of her illness, she had several peritoneal dialyses. Sevitt & Hoffbrand (1969) showed that peritoneal dialyses caused a striking fall in serum folic acid and this was undoubtedly a further significant factor in the development of folic acid deficiency in our patient. One must add that the low serum folic acid level does not prove folate deficiency, as the bacteriological assay may have been upset by the co-trimoxazole, although it is strange that a similar mechanism did not interfere with the estimation of vitamin B12.