Routine antenatal Rhesus D immunoglobulin prophylaxis: the results of a prospective 10 year study

Abstract

Objective To assess the clinical and financial impact, and identify the problems, of providing routine antenatal RhD immunoglobulin prophylaxis for Rhesus D negative nulliparae.Design A retrospective (198G1986) and prospective (1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996) comparison between two similar populations, one population with nulliparae offered routine RhD immunoglobulin 500 IU prophylaxis at 28 and 34 weeks of gestation part way through the study period, and the other population not offered prophylaxis at any time.Setting Obstetric units in two counties (three health districts) with similar annual numbers of matemities and the Regional Blood Transfusion Service antenatal serology laboratory.Participants Non-sentisitised Rhesus D negative pregnant nulliparae.Interventions Intramuscular RhD immunoglobulin 500 IU at 28 and 34 weeks of gestation to eligible women booked for confinement in one county; the intervention not offered in the other county.Main outcome measures 1. Rhesus D sensitised second pregnancy rate; 2. success in providing prophylaxis to eligible women; 3. serology laboratory activity changes; 4. potential savings from the prophylaxis programme.Prophylaxis significantly reduced iso-immunisation in the next pregnancy when compared with historical (OR 0.28, CI 0,14453; P < 0.0001) and contemporary controls (OR 0.43, CI 0.22486; P = 0.02). However, success at achieving comprehensive prophylaxis was disappointing, with only 89% of eligible women receiving the first injection, 74% both injections, and for only 29% were both at the correct gestation. Fifty-two percent of women delivered after 40 weeks of gestation, beyond the period of adequate prophylaxis protection. The savings in antenatal interventions, neonatal care and possible long term ill-health that result from very preterm birth should be considerable.Routine prophylaxis for nulliparae significantly reduces the incidence of sensitised next pregnancies with consequent savings, and its adoption nationwide should be encouraged. A programme offering antenatal prophylaxis for all Rhesus D negative women is unlikely to be economic. Improvement in uptake of prophylaxis is needed; alternative administration strategies should be explored.

General obstetrics: The kinetics of routine antenatal prophylactic intramuscular injections of polyclonal anti‐D immunoglobulin

“…Despite these observations, there is convincing evidence that antenatal anti-D prophylaxis given as a single injection at 28 weeks of gestation, intramuscularly 1,2 or intravenously 3 or as two injections at 28 and 34 weeks of gestation respectively, 4,6,18 significantly reduces the incidence of unprovoked antenatal sensitisation. This suggests that the WHO guidance for the minimal residual amount of antibody at 25 mg in the maternal circulation 12 weeks after the first injection is higher than is therapeutically necessary.…”

“…While comparisons between different studies must always be viewed with caution, due to different methodologies, it is evident that a majority of women do not have levels of IgG remaining in their circulation that are thought to be necessary to provide protection at 40 weeks of gestation. Because the administration of antenatal prophylaxis cannot be guaranteed to be given at the precise recommended gestation, and because a large proportion of women deliver beyond the expected date of confinement, 6 the proportion of women with apparently inadequate protection is quite considerable.…”

“…The optimum schedule for antenatal prophylaxis is still unclear, with two approaches having been developed including a single injection of 1500 IU at 28 weeks of gestation [1][2][3] or two injections of 500 IU at 28 weeks and again at 34 weeks of gestation. [4][5][6] Theoretically, the protocol using two injections has the potential benefit that prophylactic anti-D levels in the maternal circulation at term will be slightly higher than with the single injection protocol; the recent NICE guidance on routine antenatal prophylaxis has recommended the two injection strategy for all non-immunised RhD-negative women. 7 There have been a number of studies exploring the pharmacokinetics of the single injection prophylaxis but limited information about the uptake and persistence of detectable IgG antibody in maternal serum following the two injection protocol.…”

Frequency of Antibodies in Haemolytic Disease of Foetus and Newborn

“…35 Prevalence of Rh-D alloimmunisation from different centres had a wide range from 0.8% to 4.0% and one study conducted in the same setting reported a frequency of 3.12%. 41,42,43,44 While independent 't' test was performed between ABO and Rh-D HDFN assemblies there was no significant difference regarding maternal age, duration of treatment and duration of stay in ICU. Regarding cord blood haemoglobin and bilirubin levels, there was significant difference in mean values in ABO and Rh-D HDFN cases.…”

Diagnosis and Management of Rh Alloimmunization

“…Such routine prophylaxis for nulliparous women signifi cantly reduces the incidence of sensitized next pregnancies with consequent savings, and its adoption nationwide should be encouraged. Improvement in the uptake of prophylaxis is needed, and alternative administration strategies should be explored [14] .…”