Letter: Perinatal metabolism of diazepam.

SIR,-We have been unable to substantiate Mr. D. P. L. May's findings (22 December, p. 738). An analysis of all primigravidae delivered of single pregnancies at St. Thomas's Hospital in 1969-70 (2,972 cases) has been carried out. In this study the diagnosis of pre-eclampsia was based on the findings at the last antenatal clinic. Mild pre-eclampsia was diagnosed when the diastolic blood pressure was 90 mmn Hg or more, with either proteinuria or oedema, and severe pre-eclampsia when the diastolic pressure was 100 mm Hg or more, with proteinuria. In our series 1,356 women (4566%) were of blood group 0 and 1,176 (39-6%0) of group A. Dr. May found a very great increase in pre-eclampsia during the second half of pregnancy in women of group A compared with those of group 0. In our cases there was very little difference between these two groups at term. The incidence of mild pre-eclampsia was 5-10% (60 cases) in women of group A and 5-53% (75 cases) in those of group 0. The corresponding figures for severe pre-eclampsia were 0-60% (7 cases) and 1-18%/,. (16 cases) respectively. These differeinces are not significant statistically.-We are, etc.,