[Post-partum survival of fetal lymphocytes in the maternal blood]

Cells of fetal origin have been searched for in the peripheral blood of mothers following delivery of a boy, using mepacrine fluorescence of the Y chromosome. In a series of 62 women such cells have been found for approximately two years in more than half of cases. Their number decreases thereafter but in some instances Y chromosome-bearing cells have been observed 5 years after delivery.

Feto-maternal bleeding. During pregnancy and at delivery

Blood samples from pregnant women and from mothers before and after delivery were tested for the occurrence of feto-maternal bleeding (f.m.b.) using Kleihauers acid-elution technique and a counting technique described by Schneider. It was assumed that f.m.b. had occurred, when there was a clinically significant difference between the values of hb-F cells per million cells in two blood samples. F.m.b. had occurred in nearly 2/3 of the mothers after pregnancy and delivery. The f.m.b.'s were most often less than 0.1 ml and only a few per cent had f.m.b.'s between 0.1 and 1 ml. Abortion, complicated pregnancies, amniocentesis, pre-eclampsia, caesarean section and other kinds of complicated deliveries increased the risk of especially larger f.m.b.'s.

Pathogenesis of Rh immunization in primigravidas. Fetomaternal versus maternofetal bleeding

Rh immunization occurring during a first pregnancy with no history of preceding abortion or transfusion may result when Rh incompatible fetal to maternal bleeding ensues early enough in the gestation to initiate a maternal immune response before parturition. Alternatively, the initial antigenic stimulus could be the consequence of maternal to fetal transfer of Rh-incompatible erythrocytes while the patient herself was in utero or at the time of her own delivery. These hypotheses were tested by 1) analysis of the blood group and Rh of 22 Rh-immunized primigravidas, their infants, and their own mothers; 2) comparison of the number of fetal cells in the maternal circulation during the antepartum period in 20 women at high risk for fetal to maternal bleeding with their matched controls; and 3) Rho (D) antibody determinations in 70 Rh-negative infants born to Rh-positive mothers. The results indicate that antepartum fetal to maternal bleeding is the usual cause of Rh immunization in primigravidas, and the Rh-negative woman with blood group A, B, or AB who gestates an ABO-compatible Rh-positive male is at highest risk. The antepartum use of anti-Rho (D) immune globulin has potential prophylactic value in this situation.

Massive feto-maternal transfusion during external cephalic version, with fatal outcome

A primipara with breech presentation underwent external cephalic version under tocolysis 9 days before term. The placenta was located on the anterior uterine wall. During the version, a massive feto-maternal transfusion occurred and the baby ultimately died.

Maternal serum FDP and circulating fetal red cells throughout pregnancy. A longitudinal study

The presence of fetal red cells in the maternal circulation and the serum FDP content of 73 women was followed serially throughout a normal pregnancy. There was a signigicant increase in the mean serum FDP levels in late pregnancy, which was due to episodic elevations occurring in approximately 65% of women. These transient elevations appeared to increase in frequency and severity as pregnancy progressed. There was also an increase in the number of occasions fetal red cells were detected in the maternal circulation in the later months of pregnancy, but his phenomenon did not appear to be associated in any way to the serum FDP elevations. It is concluded that the episodic rises in serum FDP occurring in normal pregnancy are not related to episodes of occult disseminated intravascular coagulation secondary to placental haemorrhage as was previously hypothesized. Their etiology and clinical significance remain unknown.

Differences in the immunogenicity of the HL-A antigens

Comparing the expected and observed HL-A antibody forming in condition of fetomaternal immunization in 184 pregnant women, some differences in the immunogenic strength of HL-A antigens were investigated. The HL-A antigens were graded in three groups in accordance with their coefficient of immunogenicity as follows: in first group, with a coefficient more than 50 are HL-A2, HL-A7, HL-A5, W22, HL-A13, W27 and W10; in second group, with a coefficient from 25 to 50 are HL-A1, W24, HL-A11, W5, W14 and HL-A12; and in the third group, with a coefficient less than 25 are HL-A3, W25 and HL-A8. The data about the other HL-A antigens are not significant.

Complement fixing and lymphocytotoxic antibodies in serum of pregnant women at delivery. IV. Serology

The paper concerns 275 sera of pregnant women at delivery containing complement fixing platelet antibodies (CFPAb) and/or lymphocytotoxic antibodies (LCTAb). 79 sera contained operationally monospecific antibodies against platelets and/or lymphocytes. 10 sera had only CFPAb, 4 of these were C-fix anti-A. 41 sera had CFPAb and LCTAb, 18 of these were monospecific against platelets and/or lymphocytes. In 224 sera only LCTAb could be demonstrated, 57 were monospecific. Furthermore in 8 of 258 primigravidae, screened for LCTAb 6 months post partum antibodies were detected. Generally the antibodies present at delivery had disappeared or narrowed, but in 3 cases the antibodies were detectable only in the postpartum sample.

Controlled trial of various anti-D dosages in suppression of Rh sensitization following pregnancy. Report to the Medical Research Council by the working party on the use of anti-D-immunoglobulin for the prevention of isoimmunization of Rh-negative women during pregnancy

In a controlled trial phials containing 200 mug, 100 mug, 50 mug, or 20 mug of IgG anti-D were given to nearly 2,000 D-negative primiparae whose infants were D-positive and ABO-compatible. Only mothers whose serum lacked anti-D were included and the dose of anti-D was always given within 36 hours of delivery. Each phial contained the same total volume of immunoglobulin and the particular dose given to any patient was not known to the clinician. The anti-D content of the phials was estimated three times during the course of the trials and remained fairly constant. Six months after delivery the incidence of a positive indirect antiglobulin test result, indicating the presence of anti-D, in the four dose groups (with about 450 women in each group) was as follows: 0.22%, 0.23%, 0.44%, and 1.35%. The trend towards an increase in the frequency of failures as the dose decreases was significant at the level of P=0.02.In each dose group about 200 women were followed to the end of a second pregnancy with a D-positive infant. The failure rates (in order of decreasing dosage) as judged by a positive indirect antiglobulin test result at the second delivery were as follows: 1.5%, 1.1%, 1.5% and 2.9%. The differences between the dose groups were not statistically significant. The overall failure rate (1.7%) was about one-tenth of that expected in an untreated series. Though the results failed to prove any differences in success rates between doses of 200, 100, 50, and 20 mug of anti-D, they do suggest, in conformity with other evidence, that a dose of 20 mug is suboptimal for routine use. The results support the belief that a dose of 100 mug is adequate.