MATERNAL AND EARLY CHILD HEALTH

Health Evidence Bulletins - Wales

Date of Completion: 23.6.97

The contents of this bulletin are likely to be valid for approximately one year, by which time significantly new research evidence may become available


7. Isoimmunization

(Users are advised to consult the supporting evidence for a consideration of all the implications of a recommendation)

The Statements The Evidence
7a. There is evidence of the value of routine assessment of Rhesus D status and subsequent screening for antibodies (i).

(Health gain notation - 1 " beneficial")

i. British Committee for Standards in Haematology. Guidelines for blood grouping and red cell antibody testing during pregnancy. Transfusion medicine. 1996; 6: 71-74
(Type V evidence - expert opinion)
7b. Other antibodies such as c (incidence 1.3/1000 pregnant women) and Kell can on occasion cause severe haemolytic disease of the newborn (in both Rhesus D positive and negative women) and should be screened for in all pregnancies (i).
(Health gain notation - 2 "likely to be beneficial")
i. British Committee for Standards in Haematology. Guidelines for blood grouping and red cell antibody testing during pregnancy. Transfusion medicine. 1996; 6: 71-74

(Type V evidence - expert opinion)

7c. There is strong evidence of the effectiveness of anti-D immunoglobulin in the prevention of rhesus isoimmunization in Rhesus D negative women.

(Health gain notation - 1 "beneficial")

The details of who, when and how to treat are less clear(i,ii).

i. Chalmers I, Enkin M, Keirse MJNC. Effective care in pregnancy and childbirth. Oxford: Oxford University Press, 1989 pp. 565-573
(Type I evidence - systematic review. Summary in Enkin M, Keirse MJNC, Renfrew M, Neilson J. A guide to effective care in pregnancy and childbirth. 2nd ed. Oxford: Oxford University Press. 1995. p. 109);
ii. Whittle MJ. Antenatal serology testing. PACE review No. 97/02. London: Royal College of Obstetricians and Gynaecologists, 1997
(Type IV evidence - observational studies)

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7d. The most common time for fetal maternal transfusion is at delivery, following the birth of a Rhesus positive baby and routine postpartum administration of anti-D immunoglobulin (500 iu -100m g - given either immediately or within 72 hours) is effective in protecting against maternal sensitization in the majority of cases. Higher doses are required in women with evidence of larger fetomaternal bleeds (i,ii,iii)

(Health gain notation - 1 "beneficial")

i. Chalmers I, Enkin M, Keirse MJNC. Effective care in pregnancy and childbirth. Oxford: Oxford University Press, 1989 pp. 566-569
(Type I evidence - systematic review. Summary in Enkin M, Keirse MJNC, Renfrew M, Neilson J. A guide to effective care in pregnancy and childbirth. 2nd ed. Oxford: Oxford University Press. 1995. p. 110);
ii. British National Formulary March 1997. p.521
(Type V evidence - expert opinion);
iii. Letsky EA, de Silva M. Preventing rhesus immunization, Editorial British Medical Journal 1994; 309: 213-214
(Type V evidence - expert opinion)
7e. Anti-D should always be given to Rhesus negative women at evacuation after miscarriage, at therapeutic abortion or if there is an ectopic pregnancy (i).

(Health gain notation - 1 "beneficial")

i. Chalmers I, Enkin M, Keirse MJNC. Effective care in pregnancy and childbirth. Oxford: Oxford University Press, 1989 pp. 569-571, 605
(Type I evidence - systematic review. Summary in Enkin M, Keirse MJNC, Renfrew M, Neilson J. A guide to effective care in pregnancy and childbirth. 2nd ed. Oxford: Oxford University Press. 1995. p. 111)
7f. Placental trauma, procedures such as amniocentesis or the delivery of a pale distressed baby should alert carers to an increased risk of fetomaternal bleeding(i). i. Chalmers I, Enkin M, Keirse MJNC. Effective care in pregnancy and childbirth. Oxford: Oxford University Press, 1989 p. 571
(Type IV evidence - observational studies. Summary in Enkin M, Keirse MJNC, Renfrew M, Neilson J. A guide to effective care in pregnancy and childbirth. 2nd ed. Oxford: Oxford University Press. 1995. p. 111)
7g. If monoclonal techniques make anti-D immunoglobulin more freely available then routine administration of anti-D immunoglobulin at 28 weeks should prove of value. However it has been suggested that more careful application of current recommendations should be evaluated before considering routine antenatal prophylaxis or the European recommendation of a larger dose(i,ii,iii)

(Health gain notation - 2 "likely to be beneficial")

i. Crowther CA, Keirse MJNC. Anti-D administration in pregnancy. Cochrane database of systematic reviews. Cochrane Library 1997 Issue 2
(Type I evidence - systematic review with one randomised controlled trial only);
ii. Letsky EA, de Silva M. Preventing rhesus immunization, Editorial British Medical Journal 1994; 309: 213-214
(Type V evidence - expert opinion);
iii. Howard HL, Martlew VJ, McFadyen IR, Clarke CA. Preventing Rhesus D haemolytic disease of the newborn by giving anti-D immunoglobulin - are the guidelines being adequately followed? British Journal of Obstetrics and Gynaecology. 1997; 104: 37-41
(Type IV evidence - case note study of 922 women)
7h. The management of women who are shown to be sensitized with Rhesus or other antibodies known to cause haemolytic disease of the newborn requires expert care in terms of assessing severity, optimum timing of delivery and/or antenatal transfusion and postnatal transfusion, possibly best coordinated in regional centres (i).
(Health gain notation - 2 "likely to be beneficial")
i. Whittle MJ. Antenatal serology testing. PACE review No. 97/02. London: Royal College of Obstetricians and Gynaecologists, 1997

(Type IV evidence - observational studies)

7i. Other treatments such as plasmapheresis and attempts at desensitization have not been evaluated by controlled trials(i)i.
(Health gain notation - 4"unknown")
i. Enkin M, Keirse MJNC, Renfrew M, Neilson J. A guide to effective care in pregnancy and childbirth. 2nd ed. Oxford: Oxford University Press, 1995. p. 112
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Health Evidence Bulletins: Wales, Duthie Library, UWCM, Cardiff CF14 4XN. e-mail: weightmanal@cardiff.ac.uk