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Published byBianca Lory Modified over 9 years ago
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ABO System & Pregnancy hemolytic diseases of the newborn may be due to ABO incompatibility O + O = O, O + A = O or A, O + B = O or B, O + AB = O or A B Fetus inherits one gene from each parent.
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Rhesus Blood Group System First demonstrated in Rhesus monkey However the underlying biochemical genetics is not well understood and the genotyping & phenotyping remains little confused Rhesus Blood Group System The genotype is determined by the inheritance of 3 pairs of closely linked allelic genes situated on chromosome 9 named as D/d, C/c, E/e ……….. (Fisher- Race theory)
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Rhesus Blood Group System The gene ( d ) is an amorph & has no antigenic expression. So there are only five effective antigens Weiner postulates a series of allelic genes at a single locus Rh (D), Rh (C), Rh (E), Rh (c) & Rh (e) The updated system of Rosenfield refers these antigens as – Rh1, Rh2, Rh3, Rh4, Rh5 Subsequently less common antigens Cw, Du, Es have been found Rhesus Blood Group System The fetus inherits one gene from each group as a haplotype such as sets of Cde, cde etc from each parent
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Rhesus Blood Group System Incidence of Rh negative varies in different races: Mongoloids > 1, Chinese & Japanese 1-2%, Indians 5%, Africans 5-8%, Caucasians 15-17% & Basques 30-35%.
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Rhesus Isoimmunization Rhesus Iso immunization is an immunologic disease that occurs in pregnancy resulting in a serious complication affecting the fetus / or the neonate ranging from … mild neonatal jaundice … to intra uterine loss or neonatal death
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Rhesus Isoimmunization This immunologic disease occur when a Rh – negative patient carrying a Rh – positive fetus ….. had a feto – maternal blood transfusion ….. the mother immunological system is stimulated to produce antibodies to the Rh antigen on the fetal blood cell ….. This antibodies cross the placenta and destroy fetal red blood cells leads to fetal anemia …. Usually the 1st fetus will not be affected if this is the 1st time that the mother has been exposed to the rhesus positive antigen
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During pregnancy while the fetus still in the uterus The bilirubin in the fetal blood will be removed by the placenta to the maternal circulation and part of it go to the liquor The fetus will be anemic ….. If the degree of anemia is severe fetus may die in utero because of heart failure After delivery The neonate will affected by …… The degree of the anemia …… The amount of bilirubin
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Rh Negative Women Fetus Rh Neg Fetus No problem Rh positive Fetus Rh+ve R.B.C.s enter Maternal circulation previously sensitized 2nd immune response IgM…IgG antibodies Non sensitized Mother Primary immune response 1st Baby usually escapes. Mother gets sensitized? Fetus Haemolysis Pathogenesis Of Rh Iso - immunisation Man Rh positive (Hetero)
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Antigen-Antibody reaction on the RBCs surface Hemolysis IN UTERO Anemia Hepatic erythropoesis & dysfunction Portal & Umbilical Vein Hypertension … Heart Failure Erythroblastosis fetalis IUD Polyhydramnios
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Antigen-Antibody reaction on the RBCs surface Hemolysis After birth Anemia … Jaundice … Kernicterus Neonatal death Hemolysis Antigen-Antibody reaction on the RBCs surface Management of rhesus negative pregnant women Management of non sensitized Pregnancy Management of sensitized Pregnancy
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Blood Group typing at 1st visit, If negative …… Check husband’s Blood Group typing. …… If husband is also Rhesus negative then no rhesus complication and manage as other pregnant women …… If husband is Rh Positive then
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Management of non sensitized Pregnancy … If husband is Rh Positive then … Check Husband being Homozygous or Heterozygous.... Check for maternal antibodies by indirect Comb's test ( ICT ) … if antibodies detected treat as sensitized … If no antibodies Repeat ( ICT ) at 28 and 32 weeks provided that no bleeding. … If there is bleeding then …..
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Management of non sensitized Pregnancy Bleeding before 20 weeks of gestation …….. Check for fetal red blood cells in maternal circulation by Kleihauer test …….. Check for maternal antibodies ( ICT ) … if negative …….. Give ( 250 IU / 50 mcg ) anti D to the mother within 72 hours from the bleeding
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Management of non sensitized Pregnancy Bleeding after 20 weeks of gestation …….. Check for fetal red blood cells in maternal circulation by Kleihauer test …….. Check for maternal antibodies ( ICT ) … if negative …….. Give ( 500 IU / 100 mcg ) anti D to the mother within 72 hours from the bleeding …….. The dose should be doubled or tripled if fetal RBCs are more than 80 cells in maternal circulation
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Prophylactic Management of non sensitized Pregnancy During antenatal period Prophylactic (500 IU / 100 mcg ) Anti D are recommended to be given to all negative non sensitized mothers married to Rh positive husband at 28weeks and 34 weeks to protect and overcome any asymptomatic or un noticed antenatal feto maternal blood transfusion
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Prophylactic Management of non sensitized Pregnancy Indications for prophylaxis At 28weeks to a Rhesus –ve non sensitized woman whose husband is Rhesus +ve Postpartum if the woman remains non sensitized and delivers a Rhesus +ve fetus Following amniocentesis or chorionic villus sampling Following evacuation of a molar pregnancy or termination of pregnancy Following an ectopic pregnancy Following abruptio placenta or undiagnosed uterine bleeding
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Prophylactic Management of non sensitized Pregnancy Failure of prophylaxis Dose too small Dose too late >72 hours Patient already immunized but antibody titer too low for laboratory recognition Defective immune globulin given
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Management of non sensitized Pregnancy Precaution should be taken to prevent the possibility of increased chance of feto - maternal blood transfusion At birth During labor … No fundal pushing in 1st or 2nd stage of labor … No uterine massage or uterine grasp and squeeze in 3rd stage … Let the placenta to be delivered spontaneous … A void avulsions of the cord … Protect the vaginal and perineal wounds and laceration from being exposed to the fetal blood spilled from cord
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Management of non sensitized Pregnancy During cesarean section … Use abdominal packs in the sides of the uterus before opening the lower segment to prevent spilled blood from the placenta to inter the peritoneal cavity. … Let the placenta to be delivered spontaneous using control cord traction without squeezing the uterus … A void avulsions of the cord
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Management of non sensitized Pregnancy At birth ……. Maternal blood sample for …….. antibodies by indirect Comb's test ( ICT ) …….. fetal red blood cells in maternal circulation ……. Cord blood sample ( Neonatal blood sample ) for …….. antibodies by Direct Comb's test ( DCT ) …….. Infant blood group …….. Infant bilirubin level …….. Infant Hb & Hct level
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Management of non sensitized Pregnancy ……. If fetal blood group is rhesus positive ……. No antibodies detected Don’t give Anti D ……. If fetal blood group is rhesus negative ……. If Antibodies detected
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Causes of sensitization Misinterpretation of maternal Rh type Rh positive blood transfusion Unprotected pregnancy & labour Inadequate dose Anti D on previous occasions Sensitized Rh Negative mothers Factors affecting immunization and severity Amount of Antigen …… ( amount of fetal RBCs) ABO-incompatible Rh- positive cells will be hemolysed before Rh antigen can be recognized by the mother’s immune system
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Management of Sensitized Pregnancy … Check quantitative antibodies level @ 1st visit … Recheck the level every 2 weeks … Serial U/S Scan monitoring every 2 weeks … If antibodies level continuo at the same level and no fetal compromise … deliver at term Sensitized Rh Negative mothers Management of Sensitized Pregnancy If antibodies level start to increase … Arrange for amniocenteses … Spectrophotometer to study the optical density of the amniotic fluid ( i.e. bilirubin level which reflect RBCs haemolysis ) … U/S Scan evaluation of the fetal will beings … Use LILY’ s Curve to determine the fetal condition
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USS can detect …..…. Fetal Skin and scalp edema, ……... Fetal Ascites, ……... Fetal Pericardial or pleural effusion …….. Polyhydramnios …….. Fetal hepatosplenomegaly …….. Fetal Cardiomegaly …….. Placental hypertrophy and enlargements …….. Abnormal fetal posture (Buddha stance) Ultrasound scan (USS)
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Term pregnancy ( mild or Severely affected ) …Deliver Suitability of the place and its facility Experience of the team Type of Delivery Extra uterine Blood exchange Photo therapy Medication Management of Sensitized Pregnancy Preterm fetus with Zone I in ….. Cordocentesis blood sample Hb > 10g/dl No U / S Scan evidence of Hydropic changes Consider conservative management with regular follow up of fetal and maternal conditions till the fetal lung maturity is assured …. Then deliver
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Regular cheek of the fetal Hb and Hct values if the facilities available Serial U / S Scan for fetal growth and amniotic fluid Daily C T G Biophysical Profile Daily maternal clinical assessments Preterm fetus with Zone II or III Cordocentesis blood sample Hb less than 10g/dl Ultrasound evidence of Hydropic changes Consider Intra uterine therapy Delivery + extra uterine mang. Transfer to suitable place Management of Sensitized Pregnancy
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Dexamethazone to enhance lung maturity Clinical assessments + C T G + U / S Scan + B P P Lung maturity ….. If certain … deliver Consider repeating the intrauterine blood transfusion Management of Sensitized Pregnancy Intra peritoneal blood transfusion Through the umbilical vein “ Cordocentesis 80 % of packed cell “ o “ rhesus negative Blood Cross matched against maternal blood group Free of infection Fresh Intra uterine therapy Management of Sensitized Pregnancy
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