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

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 (1980-1986) and prospective (1987-1996) 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 maternities and the Regional Blood Transfusion Service antenatal serology laboratory.

Pilot trials of PDF symbology as a means of transfering data on blood units between transfusion centres.

PDF 417, a two-dimensional barcode, was used as a portable data file to transfer key information on blood units and delivery documentation between two Regional Blood Transfusion Centres. Multiple Codabar messages currently displayed on blood packs, as well as other useful information, i.e.

Prenatal determination of fetal rhesus D status by DNA amplification of peripheral blood of rhesus-negative mothers.

We have developed a sensitive PCR-based assay for the RhD gene and used it to detect circulating fetal cells from RhD-positive fetuses from peripheral blood of RhD-negative mothers. With further improvement in diagnostic accuracy, this assay may have implications in the management of RhD-sensitized pregnancies in women whose partners are heterozygous for the RhD gene. Further studies are required to determine the relationship between maternal anti-D levels and circulating fetal cell numbers.

Detection of fetal RhD sequence from peripheral blood of sensitized RhD-negative pregnant women.

A sensitive PCR-based assay was developed to amplify fetal-derived rhesus D (RhD) sequence from peripheral blood of RhD-negative pregnant women with circulating anti-D. RhD-PCR positivity was detected in 7/22 samples from women bearing RhD-positive fetuses, despite the presence of varying levels of anti-D. Evidence is presented which suggests that rising maternal anti-D levels might reduce circulating fetal cell numbers.

Anti-D concentrations in fetal and maternal serum and amniotic fluid in rhesus allo-immunised pregnancies.

Objective: To investigate the relation between anti-D concentrations in maternal serum, fetal serum and amniotic fluid, and the development of fetal anaemia.

Design: Observational cross sectional and longitudinal study.

Setting: Regional referral centre.

Computerized measurement of heart rate variation in fetal anemia caused by rhesus alloimmunization.

Objective: The purpose of this study was to examine the relationship between fetal heart rate variation and fetal hematocrit.

Study Design: In 36 red-cell alloimmunized pregnancies (mean gestational age 30, range 25 to 36 weeks) 65 computerized fetal heart rate recordings were obtained before ultrasonographically guided fetal blood sampling for the measurement of fetal hematocrit. The recordings were captured and analyzed by a microcomputer on-line.

'Partial D' women with anti-D alloimmunization in pregnancy.

We report five women with Rh 'partial D' who were found to have anti-D during pregnancy. Two patients were category IVa, their red cells typing as Go(a+); one was category VI; and two had a 'partial Du' which could not be categorized. The maternal anti-D concentration increased during four of the eight pregnancies studied, but none reached significant levels.

Rh immunization by the partial D antigen of category DVa.

Reported here is the first example of a partial D antigen stimulating the production of anti-D: stimulation was of fetal origin. During her second pregnancy, anti-D developed in the serum of a D-negative mother who had received Rh immunoglobulin after the birth of her first D-positive child. Her second baby had moderate neonatal jaundice and was successfully treated by phototherapy.

The significance of anti-Kell sensitization in pregnancy.

In a 10-year period, 407 of 350,000 pregnancies showed maternal anti-Kell allo-immunization, i.e., an incidence of 1.

Serological screening tests for syphilis in pregnancy: results of a five year study (1983-87) in the Oxford region.

Between 1983 and 1987, 62 out of 76519 pregnancies in 51 mothers had a positive miniaturised Treponema pallidum haemagglutination assay (TPHA) test--1 in 1234, or 0.81 per 1000 births. About two thirds of these mothers had syphilis and the remainder non-venereal treponematoses such as yaws or pinta.

Production of additional atypical alloantibodies in Rh(D)-sensitized pregnancies managed by intrauterine investigation methods.

The production of additional atypical alloantibodies by previously Rh(D)-alloimmunized antenatal patients can complicate the clinical management of both mother and fetus. The relative risks of stimulating additional antibodies following the use of intrauterine investigation methods currently used for the management of haemolytic disease of the newborn have been assessed. A significantly (P less than 0.

Antenatal fetal blood sampling for the management of alloimmunized pregnancies: effect upon maternal anti-D potency levels.

Increase in maternal anti-D concentrations after intrauterine investigation has been studied retrospectively in 95 rhesus (D) alloimmunized pregnancies; 48 were managed by fetal blood sampling (FBS) procedures (using fetoscopy or ultrasound-guided needle sampling) and 47 using amniocentesis. In those pregnancies where the fetus was rhesus (D) positive, the frequency of procedure-related increases (greater than 50%) in maternal anti-D potency was estimated following single procedures and found to be similar for the two methods of FBS employed (28%) and for amniocentesis (31%). The proportion of pregnancies showing an increase in anti-D potency was higher after ultrasound-guided needle sampling (75%) than after fetoscopic FBS (40%) and after amniocentesis (44%).

Serial fetal blood sampling for the management of pregnancies complicated by severe rhesus (D) isoimmunization.

Fifty-one pregnancies complicated by rhesus (D) isoimmunization have been managed by serial fetal blood sampling between 17 and 36 weeks gestation as an alternative to amniocentesis for delta OD453 measurements. In 36 pregnancies where the fetus was shown to be rhesus (D) positive and both measurements were made before any intrauterine fetal transfusions, the delta OD453 value gave misleading predictions on 13 of 63 occasions (21%). Fetal haematocrit estimations provided a direct assessment of the haemopoietic compensation occurring, but fetal bilirubin and albumin concentrations did not correlate directly with disease severity.

The significance of anti-C sensitization in pregnancy.

A study of maternal blood samples from 280,000 pregnancies in an 8-year period has shown 38 examples of anti-C (without anti-D) sensitization. This frequency (0.14/1000 pregnancies) was lower than that previously found for anti-c (0.

In-utero intravascular transfusion of the fetus for the management of severe Rhesus isoimmunization--a reappraisal.

Ten fetuses, severely affected by Rhesus (D) haemolytic disease, received one to three intravascular blood transfusions at between 18 and 30 weeks gestation, with the use of fetoscopically guided needles into one of the umbilical cord vessels. Although the technique was successfully accomplished in all cases, the fetal response to the procedure was varied. Only two fetuses survived beyond the neonatal period, and one child subsequently died principally because of the problems resulting from premature delivery.

Blood group antibody screening tests during pregnancy.

In a 2-year period 667 sera from approximately 70,000 (0.95%) antenatal patients were found to contain 726 atypical red blood cell antibodies. Overall, 66% of the immunized mothers were rhesus (D) positive.

The significance of anti-c alloimmunization in pregnancy.

In an 8-year period, 177 of 280,000 pregnancies were complicated by maternal anti-c alloimmunization. Although there was one neonatal death associated with anti-c haemolytic disease of the newborn, only two infants were severely anaemic at birth. A total of 11 babies required exchange transfusion, but nine of these developed hyperbilirubinaemia alone.

Two further examples of the low-frequency antigen Rea (Reid).

A positive direct antiglobulin reaction of a baby's cells, found during antenatal testing at Cardiff, was caused by a low-frequency antigen which has been identified as Rea (ISBT No. 700019). Investigations with this, only the second example, anti-Rea revealed another Re(a+) propositus in testing 6,635 random donors at Oxford; no further positive was found in 4,770 random donors at Cardiff.