Is anti-D immunoglobulin unnecessary in the domiciliary treatment of miscarriages?

practitioner General practitioners have been repeatedly told that they must give anti-D immunoglobulin to all Rh negative women who bleed in early pregnancy. This advice was issued by the Department of Health and Social Security in 1976' and restated many times elsewhere. Last year Entwistle and his colleagues said that the present failure of general practitioners to follow this advice was a substantial source of new sensitisations preventing further reductions in the incidence of haemolytic disease of the newborn.2 Superficially it appears that general practitioners are being negligent. The results of a survey in Wessex showed that 77 (74%) general practitioners did not give anti-D immunoglobulin to women with threatened abortions and 29 (28%) did not give it to women with complete miscarriages whom they treated at home.' Since these results were published I have made a determined but unsuccessful effort to find specific evidence about new sensitisations that occur in women with miscarriages who are not admitted to hospital. Many reports talk about "abortions" but fail to distinguish between abortions that are spontaneous and those that are surgically induced: they are two separate conditions. For example, in an analysis of deaths due to Rh haemolytic disease Clarke et al reported on the deaths due to previous "abortions," but the information provided to them did not give sufficient detail for subsequent analysis (personal communication).4 After commenting on general practitioners Entwistle et al said that sensitisation occurs as early as the ninth week of pregnancy.2 This comment was based on data from surgically induced abortions reported by Queenan, who claimed that sensitisation is facilitated by anaesthesia and curettage, neither of which is carried out in general practice.5 In 1986 Tovey wrote that sensitisation was not a notable problem in early pregnancy.6 In 1987 Hussey reported on a small survey in Mersey, and she concluded that new sensitisations did not particularly occur after early spontaneous abortions.7 In 81 newly sensitised women the cause was identified in 58; in one woman only was this due to lack of anti-D after a spontaneous miscarriage. She did not state whether this omission occurred at home or in hospital. Katz may be the only one who has looked at the conditions that we face in general practice.8 Comparing healthy pregnant women with those who had bleeding in early pregnancy, he found that there was no appreciable increase in sensitisations among women with a threatened or complete miscarriage up to the sixteenth week unless curettage was carried out. This little quoted article deserves reappraisal because if Katz's findings are correct it seems that anti-D immunoglobulin would not be required for the many women who are treated at home. I have calculated that there are at least as many women who complete their miscarriages at home as go into hospital. If 15% ofpregnancies end in a miscarriage then in England and Wales during 1983 of 625 000 deliveries there would have been 110 000 miscarriages. There were 55 000 hospital admissions that year, and 94% of those women received what is often a routine evacuation under a general anaesthetic.3 The other 55000 women remained at home. Only 217 (17%) general practitioners in the Wessex survey said that they would always admit women with apparently complete miscarriages to hospital. The problems that general practitioners experience in treating these women, who are solely in their care, are due to many causes,3 some ofwhich were mentioned by Collinge.9 But general practitioners are not the only ones failing to give anti-D immunoglobulin in early pregnancy. From the results of a postal survey Contreras et al reported on ambivalent attitudes among some haematologists and obstetricians.'0 Entwistle et al suggested that all women who cannot readily be grouped should be given anti-D immunoglobulin.2 This would mean that of every seven doses given six would be wasted on Rh positive women. Anti-D immunoglobulin is available in our area only from the hospital fridge on a named patient basis. It is still in short supply, and this was discussed in two letters to the BM. 1 12 Some of the confusion that now surrounds us might have been avoided if all reports had clearly stated the type of "abortion" that was causing new sensitisations. Abortion is an ugly word and heartily disliked by our patients. Ifwe use it ambiguously it will never serve us well, and perhaps we should now abandon it. In order to see the problem more clearly would it be possible in future for haematologists to report separately the number ofwomenwho become sensitised after (i) threatened miscarriages (early and late), (ii) spontaneous miscarriages (treated conservatively or with curettage), and (iii) the termination of unwanted pregnancies? Only when general practitioners are given this information will we fully understand when anti-D immunoglobulin is required, and it would encourage us to make the extra effort (where necessary) to identify and protect those Rh negative women who are greatly at risk.