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

Disease severity in subsequent pregnancies with RhD immunization: A nationwide cohort

BACKGROUND AND OBJECTIVES

To evaluate the severity of haemolytic disease of the foetus and newborn (HDFN) in subsequent pregnancies with RhD immunization and to identify predictive factors for severe disease.

MATERIALS AND METHODS

Nationwide prospective cohort study, including all pregnant women with RhD antibodies. All women with at least two pregnancies with RhD antibodies and RhD-positive foetuses were selected. The main outcome measure was the severity of HDFN in the first and subsequent pregnancy at risk. A subgroup analysis was performed for the group of women where RhD antibodies developed after giving birth to an RhD-positive child and thus after receiving anti-D at least twice (group A) or during the first pregnancy at risk for immunization (group B).

RESULTS

Sixty-two RhD immunized women with a total of 150 RhD-positive children were included. The severity of HDFN increased for the whole group significantly in the subsequent pregnancy (p < 0.001), although it remained equal or even decreased in 44% of women. When antibodies were already detected at first trimester screening in the first immunized pregnancy, after giving birth to an RhD-positive child (group A), severe HDFN in the next pregnancy was uncommon (22%). Especially when no therapy or only non-intensive phototherapy was indicated during the first immunized pregnancy (6%) or if the antibody-dependent cell-mediated cytotoxicity result remained <10%. Contrarily, women with a negative first trimester screening and RhD antibodies detected later during the first pregnancy of an RhD-positive child (group B), often before they had ever received anti-D prophylaxis, were most prone for severe disease in a subsequent pregnancy (48%).

CONCLUSION

RhD-mediated HDFN in a subsequent pregnancy is generally more severe than in the first pregnancy at risk and can be estimated using moment of antibody detection and severity in the first immunized pregnancy. Women developing antibodies in their first pregnancy of an RhD-positive child are at highest risk of severe disease in the next pregnancy.

Risk factors for RhD immunisation in a high coverage prevention programme of antenatal and postnatal RhIg: a nationwide cohort study

OBJECTIVE

To evaluate which risk factors for RhD immunisation remain, despite adequate routine antenatal and postnatal RhIg prophylaxis (1000 IU RhIg) and additional administration of RhIg. The second objective was assessment of the current prevalence of RhD immunisations.

DESIGN

Prospective cohort study.

SETTING

The Netherlands.

POPULATION

Two-year nationwide cohort of alloimmunised RhD-negative women.

METHODS

RhD-negative women in their first RhD immunised pregnancy were included for risk factor analysis. We compared risk factors for RhD immunisation, occurring either in the previous non-immunised pregnancy or in the index pregnancy, with national population data derived from the Dutch perinatal registration (Perined).

RESULTS

In the 2-year cohort, data from 193 women were eligible for analysis. Significant risk factors in women previously experiencing a pregnancy of an RhD-positive child (n = 113) were: caesarean section (CS) (OR 1.7, 95% CI 1.1-2.6), perinatal death (OR 3.5, 95% CI 1.1-10.9), gestational age >42 weeks (OR 6.1, 95% CI 2.2-16.6), postnatal bleeding (>1000 ml) (OR 2.0, 95% CI 1.1-3.6), manual removal of the placenta (MRP) (OR 4.3, 95% CI 2.0-9.3); these factors often occurred in combination. The miscarriage rate was significantly higher than in the Dutch population (35% versus 12.-5%, P < 0.001).

CONCLUSION

Complicated deliveries, including cases of major bleeding and surgical interventions (CS, MRP), must be recognised as a risk factor, requiring estimation of fetomaternal haemorrhage volume and adjustment of RhIg dosing. The higher miscarriage rate suggests that existing RhIg protocols need adjustment or better compliance.

Quantitation of residual D positive red cells in D negative recipients of D positive solid organ transplants

BACKGROUND

Solid organ transplants (SOT) from D positive donors are potentially sensitising events for D negative recipients. For this reason, it is important to quantify the presence of residual D positive red blood cells (RBCs) in the recipient's circulation and calculate the correct dose of prophylactic anti-D (PAD) required to prevent sensitisation. This is especially important in females of child-bearing potential where the presence of allo anti-D can, at worst, cause the death of the fetus in future pregnancies.

OBJECTIVE

This study aimed to identify the patient characteristics of D positive SOT cases referred to Red Cell Immunohaematology, NHSBT for flow cytometry investigation. This information could indicate improvements required in the current testing methodology, as well as to the calculations used to prescribe PAD for this patient group.

METHODS

Samples were investigated using a Beckman Coulter Navios Flow Cytometer using BRAD3-FITC (anti-D), AEVZ5.3-FITC (isotype matched negative control) and BIRMA17C-PE (granulocyte exclusion reagent). Mollison's calculation was used to estimate the dose of PAD required to prevent sensitisation in the D negative recipients. The calculation was adapted to consider the presence of organ donor D positive adult RBCs in the circulation of recipients instead of, larger, fetal RBCs.

RESULTS

Samples from 20 patients, all female, aged 14-53 years (one 2-year-old outlier) were referred from 2016 to September 2020. The transplants were-liver (n = 6), kidney (n = 6) and lung (n = 8). D positive cell populations were identified in 11 cases (0.1-8.0 ml); and required PAD (500-1500 IU). From these 20 patients, 10 sent a follow-up sample, where 8 required PAD top-up due to the detection of residual D positive cells (0.1-2 ml)-liver (n = 1), kidney (n = 1) and lung transplant (n = 6).

CONCLUSION

All patients in the study were D negative females, in which 18 were considered by guidelines to be of childbearing potential (2-42 years old) and 2 were >50 years old. Referrals demonstrate an awareness for the correct calculation of PAD to prevent D sensitisation. The sample size is small, but top up requirement in 8/20 of cases demonstrates accurate quantification is clearly needed to ensure the appropriate dose of PAD is provided.

Antenatal and postpartum prevention of Rh alloimmunization: A systematic review and GRADE analysis

BACKGROUND

Existing systematic reviews of Rh immunoprophylaxis include only data from randomized controlled trials, have dated searches, and some do not report on all domains of risk of bias or evaluate the certainty of the evidence. Our objective was to perform an updated review, by including new trials, any comparative observational studies, and assessing the certainty of the evidence using the GRADE framework.

METHODS

We searched MEDLINE, Embase and the Cochrane Library from 2000 to November 26, 2019. Relevant websites and bibliographies of systematic reviews and guidelines were searched for studies published before 2000. Outcomes of interest were sensitization and adverse events. Risk of bias was evaluated with the Cochrane tool and ROBINS-I. The certainty of the evidence was performed using the GRADE framework.

RESULTS

Thirteen randomized trials and eight comparative cohort studies were identified, evaluating 12 comparisons. Although there is some evidence of beneficial treatment effects (e.g., at 6-months postpartum, fewer women who received RhIg at delivery compared to no RhIg became sensitized [70 fewer sensitized women per 1,000 (95%CI: 67 to 71 fewer); I2 = 73%]), due to very low certainty of the evidence, the magnitude of the treatment effect may be overestimated. The certainty of the evidence was very low for most outcomes often due to high risk of bias (e.g., randomization method, allocation concealment, selective reporting) and imprecision (i.e., few events and small sample sizes). There is limited evidence on prophylaxis for invasive fetal procedures (e.g. amniocentesis) in the comparative literature, and few studies reported adverse events.

CONCLUSION

Serious risk of bias and low to very low certainty of the evidence is found in existing RCTs and comparative observational studies addressing optimal effectiveness of Rh immunoprophylaxis. Guideline development committees should exercise caution when assessing the strength of the recommendations that inform and influence clinical practice in this area.

Clinical value of different anti-D immunoglobulin strategies for preventing Rh hemolytic disease of the fetus and newborn: A network meta-analysis

BACKGROUND

Several anti-D immunoglobulin strategies exist for preventing Rh hemolytic disease of the fetus and newborn. This study systematically assessed the clinical value of those therapeutic strategies.

METHODS

The Web of Science, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and Wanfang databases were searched for eligible studies that evaluated the value of different anti-D immunoglobulin strategies in preventing maternal anti-D antibody sensitization. Combined odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated. The network meta-analysis was conducted using Stata 14.2 and WinBUGS 1.4.3 software.

RESULTS

Twenty-four original studies involving 64860 patients were included. Among all therapeutic measures, injecting 300 μg anti-D immunoglobulin at 28 and 34 gestational weeks (antenatal 5/E) appeared to be the most effective measure for preventing maternal antibody sensitization (surface under the cumulative ranking curve [SUCRA] = 96.8%), while a single injection at 28 gestational weeks (SUCRA = 89.2%) was the second most effective. Administering no injection or a placebo (SUCRA = 0.0%) was the least effective intervention measure.

CONCLUSION

Among the therapeutic measures, antenatal 5/E appeared to be the best method for reducing the positive incidence of anti-D antibodies in the maternal serum; thus, it may be the most effective treatment for preventing fetal hemolytic disease.

Rhesus D factor (RhD) negative women's experiences with pregnancy: An interpretive description

BACKGROUND

The development of rh immune globulin (RhIG) for the prevention of Rhesus D (RhD) alloimmunization has significantly decreased the incidence of RhD alloimmunization. Despite long-standing prevention, the experiences of RhD negative women with pregnancy is absent in the literature.

AIM

The purpose of this study was to explore the experiences of RhD negative women with pregnancy.

METHODS

Utilizing an Interpretive Description approach, semi-structured interviews were conducted with RhD negative women about their pregnancies. This study took place within the geographic context of northern British Columbia (BC). The analysis involved a two-cycle approach to identify themes within the data.

FINDINGS

Sixteen RhD negative women that live in northern BC participated in this study. The analysis identified that RhD negative women are uninformed and want to be involved in the decision-making process regarding the prevention of RhD alloimmunization. The themes that emerged from the interview data were communication, information-seeking behaviour, out of sight out of mind, choice and trust, and patient advocacy.

DISCUSSION

The participants in this study described lacking information regarding the prevention of RhD alloimmunization. They sought information to overcome the gaps in knowledge and a desire to be involved in the decision-making process.

CONCLUSION

RhD negative women want information and to be involved in the decision-making process in the prevention of RhD alloimmunization. Working with RhD negative women to develop decision-aids and/or other educational tools to aid in the decision-making process are warranted.

A case report of haemolytic disease of the foetus and newborn caused by Alloantibody D and Jka in a Rhesus D negative Nigerian woman: Justification for the implementation of universal access to prophylaxis and evidenced-based best practices

A case report of a 38 years old ABO group A and Rhesus D negative multiparous, gravidae 8 and para 2, Nigerian woman who had a case of premarital miscarriage and who was not offered anti-D prophylaxis as part of her management. Lady went on to develop alloantibody D and Jka. Lady has had 7 further pregnancies post the miscarriage. The first child who is B Rhesus D positive is the only surviving child. The surviving child was delivered severely jaundiced and needed management post-delivery for haemolytic disease of the foetus and newborn (HDFN). Lady has had a history of a stillbirth. She was given a non-clinically indicated anti-D prophylaxis during the second pregnancy despite having been previously sensitized. The second baby died 3 months after delivery from complications of HDFN. She had had a further history of 5 miscarriages. She has had challenge with conception since 2010. Alloantibody testing confirms the presence alloantibody D and anti-Jka. Finding from this is a clear case of sub-optimal laboratory, obstetric and neonatal care offered particularly to pregnant women who are Rh D negative and those with alloantibodies in Nigeria. The Nigerian government will need to implement evidenced-based best practices; determination of alloantibody status of pregnant women during their first antenatal visit; provision of facilities for alloantibody identification, titration, quantification and feto maternal haemorrhage testing (FMH); implementation of a policy on universal access to anti-D prophylaxis for pregnant Rh D negative women who are not previously sensitized; provision of facilities required for the optimal intrauterine management of HDFN (foetal genotype testing, intrauterine transfusion, doppler ultrasound to diagnose anaemia inutero and provision of donor blood that meet the minimum requirements for intrauterine transfusion); determination of Rh D status of women who require a termination of pregnancy and provision of prophylactic anti-D for those found Rh D negative within 72 hours of procedure and the optimization of the knowledge of Medical Laboratory Scientist, Obstetricians, Neonatologist, Pharmacist and Traditional Birth Attendants in a bid to reduce the residual number of women who become sensitized and the number of preventable deaths of babies with HDFN.

Single dose v two-dose antenatal anti-D prophylaxis: a randomised controlled trial

OBJECTIVE

To compare rates of detectability of circulating Rh(D)-immunoglobulin (anti-D) at delivery with single and two-dose antenatal anti-D prophylaxis (RAADP) regimens; to compare compliance with the two regimens.

DESIGN

Open label, randomised controlled trial between May 2013 and November 2015.

SETTING, PARTICIPANTS

277 women who attended a tertiary obstetric referral hospital in Perth for antenatal care and were at least 18 years of age, less than 30 weeks pregnant and yet to receive RAADP, Rh(D)-negative (negative antibody screen), and who intended to deliver their baby at the hospital. Exclusion criteria were prior anti-D sensitisation, any contraindication of anti-D administration, and a history of isolated IgA deficiency.

INTERVENTIONS

One 1500 IU anti-D dose at 28 weeks of pregnancy (single dose regimen); two doses of 625 IU each at 28 and 34 weeks of pregnancy (two-dose regimen).

MAIN OUTCOME MEASURES

The primary outcome was the proportion of women with detectable anti-D levels at delivery; the secondary outcome was compliance with the allocated RAADP regimen.

RESULTS

Circulating anti-D was detectable at delivery in a greater proportion of women in the two-dose group (111 of 129, 86%) than in the single dose group (70 of 125, 56%; P < 0.001). Compliance was not significantly different between the single dose (86 of 138, 61%) and two-dose groups (70 of 139, 50%; P = 0.06).

CONCLUSIONS

The two-dose RAADP schedule currently recommended in Australia provides better protection against Rh(D) sensitisation than a one-dose regimen.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN12613000661774).

A descriptive single-centre experience of the management and outcome of maternal alloantibodies in pregnancy

BACKGROUND

Haemolytic disease of the fetus and newborn (HDFN) occurs when maternal IgG alloantibodies to fetal red blood cell antigens cross the placenta, causing haemolysis in the fetus and/or neonate. After delivery, the main concern is hyperbilirubinaemia, which can cause neurological damage.

OBJECTIVES

To summarise our current management and outcome data to inform health-care professionals counselling women whose pregnancies are at risk of HDFN and to compare these data with relevant studies.

METHODS

This is a retrospective descriptive study of all high-risk pregnancies at risk of HDFN at Guy's and St. Thomas' NHS Foundation Trust (GSTFT) Maternity Unit over a 7-year period. We defined high-risk pregnancies as those in whom anti-D, anti-c, anti-K or high (>32 or doubling strength) titres of all other antibodies were identified.

RESULTS

A total of 130 pregnancies in 112 women were followed up. A single alloantibody was found in 93 pregnancies (71.5%) and multiple alloantibodies in 37 pregnancies (28.5%). Anti-D was most commonly encountered (n = 48, 36.9%), followed by anti-c (n = 31, 23.8%) and anti-E (n = 15, 11.5%). In 65 of 130 pregnancies (50%), antibody concentrations triggered scans to screen for fetal anaemia. Of 130 pregnancies, 6 (4.6%) required intrauterine transfusions, and 31 of 130 (26%) neonates required post-natal intervention. Overall, morbidity was 0.1% and mortality 0.002%.

CONCLUSIONS

This study demonstrates that morbidity and mortality caused by HDFN is minimal. These results are reassuring for women at risk of HDFN as even severely affected cases are successfully managed in most instances. Further studies are needed to identify predictors of disease severity.

Rh(O)D immune globulin products for prevention of alloimmunization during pregnancy

PURPOSE

The pharmacologic properties of Rhesus (Rh) immune globulin (RhIG) and clinical data on its effectiveness in preventing Rh-antigen alloimmunization in pregnant women are reviewed.

SUMMARY

RhIG is a human plasma derivative that targets red blood cells (RBCs) positive for Rh(O) antigen (also called D antigen). In the United States and other countries, the widespread use of RhIG has markedly reduced the occurrence of hemolytic disease of the fetus and newborn (HDFN), a devastating condition caused by D-antigen sensitization of a pregnant woman via exposure to fetal RBCs (usually during detachment of the placenta in labor) that results in a maternal immune response leading to severe hemolysis in the fetus. Routine administration of RhIG at 26-30 weeks' gestation and again within 72 hours of delivery has been shown to be highly effective in preventing maternal Rh alloimmunization, with very low rates of D-antigen sensitization (in the range of 0-2.2%) reported in multiple studies of at-risk women. The four RhIG products currently available in the United States have common clinical indications but differ in certain attributes. Pharmacists can play an important role in guiding other clinicians on the rationale for the use of RhIG, important differences between products, and appropriate timing of RhIG therapy.

CONCLUSION

Routine administration of RhIG to women at risk for Rh alloimmunization is clinically effective and has made HDFN a rare clinical event. The available RhIG products are not the same and should be carefully reviewed to ensure that they are administered safely.

Appropriate provision of anti-D prophylaxis to RhD negative pregnant women: a scoping review

BACKGROUND

The purpose of this scoping review was to review the literature on healthcare provider provision of anti-D prophylaxis to RhD negative pregnant women in appropriate clinical situations in various healthcare settings.

METHODS

A scoping review framework was used to structure the process. The following databases were searched: CINAHL (EBSCO), EBM Reviews (OvidSP), Embase (OvidSP), Medline (OvidSP), and Web of Science (ISI). In addition, hand searching of article references was conducted. The search yielded 301 articles. Thirty-five articles remained for review after screening. Two team members reviewed each article using a detailed data collection sheet. A third reviewer was utilized if discrepancies occurred amongst reviewers.

RESULTS

The review process yielded 18 included articles. The majority of the studies were conducted in the United Kingdom. Of the 18 studies, 15 were retrospective studies. The articles were largely conducted in one institution. The articles with a focus on routine antenatal provision of anti-D immunoglobulin found that it was given 80 to 90% of the time. Postpartum provision of anti-D immunoglobulin had significantly higher results of 95-100%. The review found that the delivery of anti-D immunoglobulin to RhD negative pregnant women during situations of potential sensitizing events was suboptimal.

CONCLUSIONS

The included articles examine the management of RhD negative pregnancies in various countries with existing national guidelines. The existing evidence indicates an opportunity for quality improvement in situations where potential sensitizing events are not at routine times in pregnancy, such as miscarriage or fetal demise early in pregnancy. Routine care for the prevention of RhD alloimmunization in pregnancy and postpartum appears to be fairly consistent. The paucity of recent literature in this area leads to a recommendation for further research.

Survey on the prevention and incidence of haemolytic disease of the newborn in Italy

BACKGROUND

In 2010, the Italian Society of Immunohaematology and Transfusion Medicine (SIMTI) carried out a survey of the incidence of haemolytic disease of the newborn (HDN) and the prevention of HDN caused by anti-Rh(D) in Italian Transfusion Structures (TS).

MATERIALS AND METHODS

A questionnaire divided into the following five sections was administered: (i) types of services provided and maintenance of legally required registers, (ii) immunoprophylaxis (IP), (iii) red cell typing and searches for irregular antibodies, (iv) evaluation of foetal-maternal haemorrhage (FMH), and (v) incidence of HDN in 2010. Of the 280 TS sent the questionnaire, 176 (63%) replied.

RESULTS

A HDN register was available in 55.5% of the TS (n =91). Immunoprophylaxis with a dose of anti-D IgG was given to all Rh(D) negative and Rh(D) variant puerpera with Rh(D) positive newborns: in more than 93% of cases the dose was between 1,500 IU (300 μg) and 1,250 IU (250 μg). Antenatal IP between the 25(th) and 28(th) week was proposed by 42 TS (26%). Seventy percent of the TS (n =115) did not make any evaluation of FMH. The number of births surveyed in 2010 was 203,384, the number of Rh(D) negative pregnancies was 13,569, while anti-D antibodies were present in 245 pregnancies. There were 111 cases of HDN due to anti Rh(D) incompatibility and in 40 of these, intrauterine transfusion (n =8) or exchange transfusion (n =32) was necessary. In 94 cases HDN was due to other irregular antibodies: in 4 of these cases intrauterine transfusion was needed and in 11 other recourse was made of exchange transfusion. Finally, there were 1,456 newborns with ABO HDN of whom 13 underwent exchange transfusion.

DISCUSSION

The data collected give a picture of the incidence of HDN in Italy and of the methods of managing IP and could form the basis for an update of the SIMTI recommendations on the management and prevention of this disease.

Routine antenatal anti-D prophylaxis in women who are Rh(D) negative: meta-analyses adjusted for differences in study design and quality

BACKGROUND

To estimate the effectiveness of routine antenatal anti-D prophylaxis for preventing sensitisation in pregnant Rhesus negative women, and to explore whether this depends on the treatment regimen adopted.

METHODS

Ten studies identified in a previous systematic literature search were included. Potential sources of bias were systematically identified using bias checklists, and their impact and uncertainty were quantified using expert opinion. Study results were adjusted for biases and combined, first in a random-effects meta-analysis and then in a random-effects meta-regression analysis.

RESULTS

In a conventional meta-analysis, the pooled odds ratio for sensitisation was estimated as 0.25 (95% CI 0.18, 0.36), comparing routine antenatal anti-D prophylaxis to control, with some heterogeneity (I²  =  19%). However, this naïve analysis ignores substantial differences in study quality and design. After adjusting for these, the pooled odds ratio for sensitisation was estimated as 0.31 (95% CI 0.17, 0.56), with no evidence of heterogeneity (I²  =  0%). A meta-regression analysis was performed, which used the data available from the ten anti-D prophylaxis studies to inform us about the relative effectiveness of three licensed treatments. This gave an 83% probability that a dose of 1250 IU at 28 and 34 weeks is most effective and a 76% probability that a single dose of 1500 IU at 28-30 weeks is least effective.

CONCLUSION

There is strong evidence for the effectiveness of routine antenatal anti-D prophylaxis for prevention of sensitisation, in support of the policy of offering routine prophylaxis to all non-sensitised pregnant Rhesus negative women. All three licensed dose regimens are expected to be effective.

Evidence to support the single-dose over the two-dose protocol for routine antenatal anti-D Rhesus prophylaxis: a prospective observational study

OBJECTIVE

To assess the potential benefit of the single-dose compared with two-dose protocol for routine antenatal anti-D prophylaxis (RAADP).

STUDY DESIGN

Prospective observational study during February to October 2009 in a district teaching hospital delivering 6000 women annually. Obstetric notes of eligible RhD negative women were reviewed following delivery to identify gestation and dose for RAADP injections, with laboratory confirmation when necessary. The primary outcome was compliance administering RAADP at the appropriate gestation with the secondary analysis of compliance for nulliparae and multiparae.

RESULTS

For 644 eligible women, there was no statistically significant difference in administering the 28 week injection between the two-dose (95%) and single-dose (98%) protocols (P=0.17, OR 2.47: 95%CI (0.73, 8.34)). Compliance giving the injection at the correct gestation at 28 ± 1 weeks was achieved in 78% and 77% respectively (P=0.72, OR 1.10: 95%CI (0.69, 1.74)). For the two-dose protocol the second injection was given to 96% of those who had received the first injection, but at the correct time point in only 67%. By eliminating the variability of the 34 week injection, the single-dose protocol resulted in significantly greater overall success in giving RAADP at the appropriate times compared with the two-dose protocol (P=0.021, OR 1.68: 95%CI (1.08, 2.64)). There were no differences between nulliparae and multiparae for both protocols.

CONCLUSION

The single-dose protocol provides enhanced compliance over the two-dose protocol with the potential for reduced sensitisation combining economic and manpower benefits. There remains room for improvement in administering RAADP at the correct gestation.

Clinical validation of routine antenatal anti-D prophylaxis questions the modelling predictions adopted by NICE for Rhesus D sensitisation rates: results of a longitudinal study

OBJECTIVE

To compare the rates of Rh(D) sensitisations with a policy of restricted routine antenatal anti-D prophylaxis (first pregnancy only) with the rates predicted with universal routine antenatal anti-D prophylaxis (all pregnancies).

STUDY DESIGN

A retrospective longitudinal observational study involving 15,500 confinements in Rhesus D negative (Rh(D)-ve) women between 1990 and 2003 in a single health district was conducted. All Rh(D) sensitised pregnancies were identified and evidence for routine antenatal anti-D prophylaxis administration during the first pregnancy was investigated. The rate of Rh(D) sensitisations following a policy of restricted prophylaxis was compared with that predicted with mathematical modelling following universal prophylaxis.

RESULTS

There were 50 newly sensitised and 37 previously sensitised pregnancies among 15,596 Rh(D)-ve women. For the calculated 13,575 Rh(D)-ve women whose first confinement was in Oxford and who were eligible for restricted prophylaxis, there were 30 new and 26 previously sensitised pregnancies. Of these 30 new sensitisations, 10 were nulliparae, 12 parity 1, and eight parity 2 or greater (third or later continuing pregnancy); only one of these latter eight women had received routine prophylaxis, four had delivered their first baby before the programme was introduced, and in three documentary evidence could not be confirmed that prophylaxis had been given. There was no difference between a policy of restricted and universal routine antenatal anti-D prophylaxis in the sensitisation rates for women during their third or subsequent pregnancy.

CONCLUSIONS

This study has shown that restricted routine antenatal prophylaxis provides continuing protection for subsequent pregnancies although the mechanism for this is unclear. These results challenge the wisdom and expense of a policy of universal prophylaxis and prompt a need for further similar analyses to test the appropriateness of the NICE guideline.

Routine antenatal anti-D prophylaxis and patient compliance with the two-dose regimen

The aim of this study was to determine the compliance rates for women being offered routine antenatal anti-D prophylaxis in two obstetric units in the UK. Haemolytic disease of the newborn (HDN) is a potentially serious condition that can result in substantial morbidity and sometimes death. Current guidelines recommend that 500 IU anti-D immunoglobulin G (IgG) should be offered to all non-sensitized RhD-negative women at 28 and 34 weeks' gestation in order to prevent the risk of RhD sensitization in pregnancy. Implementing guidance, however, remains a challenge. We conducted a retrospective audit of 207 RhD-negative, non-sensitized pregnant women attending obstetric units during 2004 to assess compliance with national guidance on the provision of antenatal anti-D prophylaxis. Informed consent for routine antenatal anti-D prophylaxis was documented for 185 of these women. In total, 86.5% of women received the two doses of anti-D IgG. The majority of women received their first and second doses within 1 week of 28 and 34 weeks' gestation (87.0 and 86.0%, respectively). Accurate records of prophylactic anti-D IgG were maintained and updated. This audit demonstrates that the level of patient compliance with the two-dose regimen was high.

Fetal anaemia: diagnosis and management

Fetal anaemia can by treated by in-utero therapy, which results in a significant improvement in perinatal outcome. The important causes of fetal anaemia are rhesus alloimmunisation, kell alloimmunisation and parvovirus infection. At-risk pregnancies require serial monitoring to ensure timely intervention with intrauterine transfusion. Non-invasive testing with middle cerebral artery Doppler is becoming the monitoring modality of choice.

Rhesus immune globulin fails to prevent immunization after rhesus incompatible blood transfusion

The transfusion of rhesus positive (D+) red blood cells to a rhesus negative (D-) person usually induces the development of an irregular anti-D antibody in the recipient. This can lead to a hemolytic reaction in subsequent transfusions, and, in women of childbearing age, can lead to fetal erythroblastosis in any future pregnancy. The recommended interventions to avoid the immunization of the recipient include the administration of intravenous rhesus immune globulin within 72 h after the transfusion. We report the case of a D- woman who received one unit of D+ red blood cells and a total of 40 units of D- red blood cells after severe trauma. In spite of treatment with rhesus immune globulin, the patient developed anti-D antibodies.

Compliance with routine antenatal rhesus D prophylaxis and the impact on sensitisations: observations over 14 years

Documented routine antenatal anti-D prophylaxis was given to 90% and 81-87% of eligible women at 28 and 34 weeks of gestation, respectively, during the early 1990s and early 2000s. With increasing experience and education, a significant improvement in the timing of the first (OR 0.26, 95% CI 0.16-0.41: P < 0.0001) and second injections (OR 0.40, 95% CI 0.26-0.61: P < 0.0001) occurred during the latter period. Despite these improvements, there was no reduction in the sensitisation rate at 0.4%. However, this low rate occurred despite significant proportions of women delivering more than 42 days after the second injection. Fifteen of the 16 sensitised women had received routine antenatal prophylaxis.

The kinetics of routine antenatal prophylactic intramuscular injections of polyclonal anti-D immunoglobulin

OBJECTIVE

To observe the pharmacokinetics of intramuscular anti-D immunoglobulin (IgG) given for routine antenatal prophylaxis.

DESIGN

Prospective observational study.

SETTING

Maternity unit and antenatal serology laboratory in a district teaching hospital.

POPULATION

Forty-five rhesus-D-negative pregnant women not sensitised to RhD.

METHODS

Serial serum quantitations of anti-D IgG following the intramuscular injections of anti-D IgG 100 microg (500 IU) at 28 and 34 weeks of gestation. Anti-D IgG concentrations were assayed with the RFA-300 continuous flow analyser.

MAIN OUTCOME MEASURES

The kinetic profile and duration of detectable anti-D IgG in maternal serum following the first and second injections of anti-D IgG.

RESULTS

For the 43 women in whom serial data were collected, there were no detectable differences between pregnancies with an RhD-positive (26) or -negative (17) fetus. Maximum IgG concentrations were detected two to five days following the first anti-D IgG injection and ranged between 0 and 28 ng/mL. Only 30% of women still undelivered at 40 weeks of gestation had detectable IgG at 2 ng/mL or greater. There was a significant relationship between higher maximum values and low maternal surface body area (R2 = 0.204, P = 0.002), but this did not influence duration of persistent IgG.

CONCLUSION

Using previously published data, 70% women are not adequately protected with anti-D IgG 12 weeks after the first prophylactic injection. Despite this, previous clinical results suggest that the antenatal prophylaxis schedule used provides adequate protection and that the recommendation for the lowest concentration of protective anti-D IgG antibody levels currently in use is probably overestimated.

Diagnosis and management of Rh alloimmunization

OBJECTIVE

To assess the current problem of alloimmunization in a tertiary referral center in Croatia. The results obtained were compared to data published worldwide.

METHODS

Retrospective case analysis included women with Rhesus (Rh) alloimmunization treated in our department from January 1997 to January 2003. Data of interest included the incidence, prevention, diagnosis and treatment, with the final point being perinatal mortality and morbidity.

RESULTS

23 pregnant women with alloimmunization were identified. The incidence was 0.138% of deliveries in the same time period. The median gestational age at diagnosis/referral was 22 (range 9-37) weeks. Anti-D antigen, alone or in combination with the other antigens, was responsible for more than 90% of the alloimmunization cases included. A defined protocol for prevention of Rh D immunization after previous delivery was not followed properly in 9/19 cases. A particular problem was prophylaxis after previous pregnancy termination (TOP), whereby only 1/14 woman received adequate prophylaxis and only after 2 of 5 TOPs. Regarding fetal treatment, 9/23 women had a total of 24 intrauterine intravascular blood transfusions. Overall, perinatal mortality was 13%, and the median gestational age at delivery was 34 (range 31-40) weeks. In all there were 31 fetal exchange transfusions after delivery performed in 14/20 newborns.

CONCLUSION

Despite precise diagnostic criteria and modern therapeutic options, alloimmunization remains a problem in Croatia. It is still related with a high perinatal mortality and morbidity. The main problem is inadequate prevention.

Potentially Avoidable Maternity Complications: An Indicator of Access to Prenatal and Primary Care During Pregnancy

OBJECTIVE

We identified Potentially Avoidable Maternity Complications (PAMCs). Used with hospital discharge data, PAMCs may indicate lack of prenatal care access.

METHODS

A research team of two obstetrician/gynecologists and three health services researchers developed the PAMC indicator, which was verified by external review. AIM 1 used the National Maternal and Infant Health Survey, with prenatal care information and 8,661 pregnancy hospitalizations, to examine associations between prenatal care, risk factors, and PAMCs. AIM 2 used the 1997 Nationwide Inpatient Sample (NIS), with 895,259 pregnancy-related hospitalizations, to examine PAMC risks for groups likely to have prenatal care access problems.

RESULTS

In AIM 1, adequate prenatal care reduced PAMC risks by 57% (p < .01). Compared to nonsmokers, the odds of a PAMC for smokers were 86% higher (p < .01). Cocaine use increased PAMC risk notably (odds ratio 3.35, p < .0001). In the multivariate analyses of AIM 2, African Americans, the uninsured, and Medicaid beneficiaries had high PAMC risks (all p < .0001).

CONCLUSIONS

Findings suggest adequate prenatal care may reduce PAMC risks. Results for groups with less prenatal care access were consistent with previous research using less refined indicators, such as low birth weight. PAMCs improve on earlier measures, and readily permit adjustments for mothers' ages and comorbidities.

Efficacy and safety of a new, chromatographically purified rhesus (D) immunoglobulin

OBJECTIVES

To study the efficacy, safety, and tolerability of the 300 microg dose of a new chromatographically produced rhesus immunoglobulin (Rhophylac 300) for ante- and postnatal rhesus prophylaxis.

DESIGN

In an open-label multi-centre study, rhesus D (RhD)-negative women were randomly allocated to receive Rhophylac 300 either intravenously or intramuscularly at the 28th week of gestation and within 72 h after delivery of an RhD-positive child. Serum samples were obtained prior to the antenatal dose and 6-11.5 months after delivery of an RhD-positive child and tested by the indirect antiglobulin test and papain test for anti-D. Safety parameters were assessed in all women who were treated with the study drug.

RESULTS

Four hundred and thirty two women received the study drug antenatally. No differences were detected in efficacy or tolerability between intravenous and intramuscular administration. Of the 261 women who delivered an RhD-positive child and received rhesus prophylaxis according to the protocol, 248 women returned for follow-up investigations. None of them had detectable anti-D at their last visit. There were no serious adverse events, no cases of infectious disease transmission nor clinically relevant changes in laboratory safety values and vital signs attributable to the study drug.

CONCLUSIONS

The results suggest that Rhophylac 300 given intravenously or intramuscularly is safe and efficacious in preventing rhesus (D) immunisation.

Audit of anti-D immunoglobulin administration to pregnant Rhesus D negative women following sensitising events

We performed a retrospective audit of 99 Rhesus D (RhD) negative women to discover if anti-D immunoglobulin (anti-D) prophylaxis was given in accordance with guidelines from the National Blood Transfusion Service Immunoglobulin Working Party (1991). It was found that all patients received appropriate management postpartum. However, more than half of the antepartum sensitising events beyond 20 weeks' gestation were not managed according to the guidelines. Only one patient was sensitised during the studied pregnancy and no sensitising events were recorded in her case. This supports the introduction of a policy of routine anti-D prophylaxis in the third trimester.

The economics of routine antenatal anti-D prophylaxis for pregnant women who are rhesus negative

OBJECTIVE

To investigate the economics of routine antenatal anti-D prophylaxis in the prevention of haemolytic disease of the newborn, in support of the NICE appraisals process.

DESIGN

Cost effectiveness analysis.

SETTING

UK NHS.

POPULATION/SAMPLE

Pregnant women who are RhD-negative.

METHODS

A model was constructed to estimate the incremental cost effectiveness and cost utility of: (1) offering routine antenatal anti-D prophylaxis to all pregnant women who are RhD-negative; (2) offering routine antenatal anti-D prophylaxis to RhD-negative primigravidae, compared with conventional management alone. Effectiveness estimates were derived from a meta-analysis of two UK community-based studies. Costs were derived from published sources and NHS product lists. Threshold analysis was conducted to reflect the social value of routine antenatal anti-D prophylaxis through incorporating valuations of parental grief and fetal/neonatal loss.

MAIN OUTCOME MEASURES

Cost per life year gained and cost per quality adjusted life year (QALY) gained.

RESULTS

The cost per life year gained is in the range pound 5,000- pound 15,000. The inclusion of long term neurodevelopmental problems results in a cost utility ranging between pound 11,000 and pound 52,000 per QALY gained. Threshold analysis suggests that if fetal loss, parental grief and subsequent high intervention pregnancy are valued at greater than 9 QALYs, the comprehensive policy would be more attractive than the primigravidae policy, assuming a maximum acceptable threshold of pound 30,000 per QALY.

CONCLUSION

Routine antenatal anti-D prophylaxis provides a cost effective intervention for preventing haemolytic disease of the newborn in the pregnancies of women who are RhD-negative.

Treatment of fetal anemia due to red-cell alloimmunization with intrauterine transfusions in the Netherlands, 1988-1999

OBJECTIVE

To assess pregnancy outcome after intrauterine transfusion (IUT) for fetal anemia due to red-cell alloimmunization in the Netherlands over 11 years, in order to improve care and counseling.

METHODS

A retrospective cohort study was conducted from January 1, 1988, to January 1, 1999. Data were collected prospectively on all red-cell alloimmunized pregnancies requiring intrauterine blood transfusions. Primary outcome variables were fetal and neonatal survival in relation to the type of antibody, gestational age and presence or absence of hydrops. In addition, we studied short-term neonatal morbidity and procedure-related complications.

RESULTS

A total of 210 fetuses from 208 pregnancies received 593 transfusions. Overall survival rate was 86%. Survival of hydropic fetuses (78%) was significantly different from those without hydrops (92%). Low survival rates were especially found in hydropic fetuses with the first transfusion at gestational ages of 20 weeks or less (55%) or between 28 and 32 weeks (59%). In maternal rhesus D [Rh(D)] immunization 89% of fetuses survived, whereas survival in the case of Kell immunization was 58%. All fetuses with anemia due to Rh(c) immunization survived. The overall fatal procedure-related complication rate was 1.7% per procedure, resulting in a fetal loss rate of 4.8%.

CONCLUSIONS

Intrauterine intravascular transfusions are effective in the management of fetal alloimmune anemia. Fetal hydrops, mostly associated with late referral, decreases the chance of survival. To improve the outcome of red-cell alloimmunized pregnancies early diagnosis of fetal anemia and referral to a specialized center are important, enabling the start of treatment before hydrops develops.