Fetomaternal Transplacental Hemorrhage during Pregnancy and after Delivery

Abstract

One third of very weakly Rh-immunized women show no increase in their level of Rh immunization during pregnancy and after delivery. Administration of 300 pg of Rh immune globulin at 6-week intervals does not alter the incidence of lack of progression of Rh immunization in such women. Thirty-three Rh-positive women who ultimately delivered ABO-compatible babies, had Kleihauer fetal transplacental hemorrhage (TPH) screening tests carried out at 2-week intervals during pregnancy and shortly after delivery. One third of the 33 women had no detectable TPH (8) or a TPH of 0.01 ml of fetal red cells (3). We conclude that one third of weakly Rh-immunized women failed to show any progression of their Rh immune response during pregnancy or after delivery because they were exposed to too few fetal red cells (0.01 ml or less) to produce such a response.

The maternal immune response to fetal platelet GPIbα causes frequent miscarriage in mice that can be prevented by intravenous IgG and anti-FcRn therapies

“…The GPIbα -/-female mice immunized with WT platelets in this model may mimic the human mothers who have had previous pregnancies in which the maternal immune system is exposed to fetal/neonatal antigenpositive platelets due to uterine injury during delivery (58, 59) and thus may generate anti-GPIbα antibodies. Maternal immunization against fetal platelet GPIbα may also occur during human pregnancy when fetal GPIbα antigen-positive platelets leak into the maternal circulation via fetomaternal hemorrhage (58,59). Since (a) β3 integrin (GPIIIa) is expressed on human placental syncytiotrophoblast microvilli that are in direct contact with maternal blood and may induce the immune response against HPA-1a on β3 integrin in primiparous mothers (60,61) and (b) GPIbα has been reported to be expressed on human endothelial cells under certain conditions (62-64), we cannot exclude the possibility that GPIbα, like β3 integrin, may also be expressed on placental syncytiotrophoblasts and endothelial cells, thus contributing to maternal anti-GPIbα antibody generation during pregnancy.…”

Effect of Rhesus Negative in Pregnancy

“…In the present study the fetal outcome in sensitized patients showed that overall fetall loss due to Rh immunization was 14% which was nil in the primigravid patients, Incidence was higher because of lack of facility for neonatal management. According to the Bowman 9 work about 17% of Rh negative women become isoimmunized without preventable measures after the delivery of her first child (Harrod et al 2003) 10 . This number is very high possible because the sample size was small and most of the immunized patients had history of repeated unprotected deliveries.…”

Anti-D Prophylaxis Reviewed in the Erea of Foetal RHD Genotyping

“…Throughout pregnancy, foeto-maternal haemorrhage increases in frequency (from 3% during the first trimester to 45% during the third one), and in volume (<0.1 mL during the first trimester and in variable amounts during the third one) [8]. A dose-dependant correlation is known to exist between the volume of foeto-maternal haemorrhage and the occurrence of allo-immunisation.…”