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Objective: To provide guidelines on use of anti-D prophylaxis to optimize prevention of rhesus (Rh) alloimmunization in Canadian women., Outcomes: Decreased incidence of Rh alloimmunization and minimized practice variation with regards to immunoprophylaxis strategies., Evidence: The Cochrane Library and MEDLINE were searched for English-language articles from 1968 to 200 I, relating to the prevention of Rh alloimmunization. Search terms included: Rho(D) immune globulin, Rh iso- or aile-immunization, anti-D, anti-Rh, WinRho, Rhogam, and pregnancy. Additional publications were identified from the bibliographies of these articles. All study types were reviewed. Randomized controlled trials were considered evidence of highest quality, followed by cohort studies. Key individual studies on which the principal recommendations are based are referenced. Supporting data for each recommendation is briefly summarized with evaluative comments and referenced., Values: The evidence collected was reviewed by the Maternal-Fetal Medicine and Genetics Committees of The Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the Evaluation of Evidence guidelines developed by the Canadian Task Force on the Periodic Health Exam., Recommendations: VALIDATION: These guidelines have been reviewed by the MaternalFetal Medicine Committee and the Genetics Committee, with input from the Rh Program of Nova Scotia. Final approval has been given by the Executive and Council of The Society of Obstetricians and Gynaecologists of Canada., Sponsors: The Society of Obstetricians and Gynaecologists of Canada., (Copyright © 2018. Published by Elsevier Inc.)

To improve routine D typing and define transfusion strategy, it is important to establish the frequency of partial D alleles and their susceptibility to anti-D alloimmunization due to transfusion or pregnancy. We identified the partial D DNB that was caused by an RHD(G355S) allele associated with a CDe haplotype and whose phenotype presented a normal D in routine typing. The antigen density was about 6000 D antigens per red blood cell, and the Rhesus index was 0.02. Five anti-D immunization events with allo-anti-D titers up to 128 were observed. Twelve carriers of DNB were whites of Central Europe; the only Danish proband had Austrian ancestry. DNB was the most frequent partial D recognized so far in whites, occurring with frequencies of up to 1:292 in Switzerland. DNB was the underlying partial D phenotype in a relevant fraction of anti-D immunizations occurring in whites.

Fetomaternal hemorrhage can result from different types of trauma and may be followed by fetal anemia, fetal death, or isoimmunization. We prospectively studied the frequency and volume of fetomaternal hemorrhage, fetal well-being, abruptio placentae, and fetal outcome in 32 pregnant patients suffering recent trauma. Fetomaternal hemorrhage occurred in nine of 32 trauma patients (28%) with a mean volume of 16 ml +/- 14.3(SD). There was a statistically significant difference in the frequency and mean volume of fetomaternal hemorrhage in this group over that in gestational-age-matched controls. Neither the nature of the trauma nor the gestational age was related to the frequency or volume of fetomaternal hemorrhage. The outcome in three of the nine trauma patients who sustained fetomaternal hemorrhage was poor; fetal anemia, paroxysmal atrial tachycardia, and fetal death occurred in each one. Maternal trauma remains a significant cause of maternal and fetal morbidity and death, and the use of the Kleihauer-Betke analysis is indicated to identify fetomaternal hemorrhage. Rh-immune globulin therapy should be given to Rh-negative patients with fetomaternal hemorrhage.

Maternal serum alpha-fetoprotein concentrations were determined by radioimmunoassay in 72 patients immediately before and after chorionic villus sampling for prenatal diagnosis. Fifty percent showed a rise of greater than or equal to 5 ng/ml. Assuming such rises represent fetal blood crossing the intervillous space, in 14% of the cases greater than or equal to 60 microliters of fetal blood was transferred at the time of chorionic villus sampling. A positive correlation was found between the magnitude of rise in maternal serum alpha-fetoprotein levels and the amount of villi removed (r = 0.39, p less than 0.001). When cases were examined by number of passes, a greater rise in maternal serum alpha-fetoprotein levels was noted with multiple passes than with single passes for a given sample size. The transfer of greater than or equal to 60 microliters of fetal blood suggests that maternal sensitization to fetal antigens may occur after chorionic villus sampling. During biopsy, as small a sample of villi as necessary for diagnosis should be taken with as few catheter passes as possible.

Since immune memory in Rh(D)-negative isoimmunized subjects remains through life, even in the absence of measurable anti-Rh(D), we investigated the transformation of lymphocytes from such donors by Rh(D) antigen. The time lapse from the last stimulus was up to 13 years. Mononuclear cells from immunized women were stimulated by Rh(D)-positive erythrocyte stroma. Maximum transformation was observed on the sixth day of culture, with a stroma protein concentration of 8 micrograms/mL of culture medium. The stimulation index (SI) in cells from 11 immunized women was 6.8 +/- 3.1 (mean +/- SD), with a range from 3.1 to 15.0. In five different sets of control cultures, the SI ranged from 0.9 +/- 0.2 to 1.3 +/- 0.4. There was no overlap between stimulated and control cultures. No anti-D could be demonstrated in the serum of four of the 11 immunized cases studied. Also, transformation was observed in mononuclear cells from Rh(D)-negative immunized women with Rh(D)-positive erythrocytes. The findings demonstrate that lymphocytes from isoimmunized Rh(D)-negative subjects maintain the immune memory and are transformed in vitro by the Rh(D) isoantigen.