ABO and Rh Incompatibility

presented byMaria Sol Solano RN IV

BSN CLC IBCLC

ABO Blood Types

• 4 Principal Types• determined by the presence of 2 antigens and

2 antibodies

Blood Type Antigen Antigen Antibody Antibody A B anti-A anti-B

A yes yes B yes yes O yes yes AB yes yes

O -universal donorAB -universal recepientRh or Rhesus factor is an antigenABO/Rh incompatibility may result in - Erythroblastosis Fetalis - Hemolytic Disease of the Newborn

Antibody Test (Coomb's Test)

• to find antibodies that attack RBC's• antibodies are proteins made by the immune system• bind to foreign substances such as bacteria and

viruses and causes them to be destroyed

Conditions that causes antibody production

• ---blood transfusion reaction• ---Rh sensitization

• Direct Coomb's Test• done on RBC's• detects antibodies attached to RBC's

• Indirect Coomb's Test• done on serum• detects antibodies present in the blood stream• could bind to certain RBC's

Rhogam

• Rho(D)Immune Globulin (Human)• RhoGam 300ug• MicRhoGam 50ug

Action

• suppresses the immune response of Rh- individuals to Rh+ RBC's

• not effective in altering the course or consequences of Rh immunization once it occurred

OB Use

• the Rh- OB patient may be exposed to RBC's from her Rh+ fetus during the normal course of pregnancy,

• after an OB procedure,• or abdominal trauma

Clinical Studies

• reduction of Rh sensitization in pregnancy from 12-13% to 1-2% with RhoGam administration within 72 hours PP

• antepartum administration at 28 wks as well as within 72 hours PP reduced the rate 0.1-0.2%

• 3 hours post abortion administration was 100% effective

Use after incompatible blood transfusion

• Rh immunization can occur even with <1ml of Rh+ blood transfused

• RhoGam or MicRhoGam is administered within 72 hrs. post BT of incompatible RBC's

Indications

• pregnancy/delivery of an Rh+ baby regardless of blood types

• abortion/threatened abortion at any stage of pregnancy

• ectopic pregnancy• antepartal fetal/maternal bleed(suspect/proven) as

in placenta previa,amniocentesis,CVS,PUBS,versions or abdominal trauma

• transfusion of incompatible blood or blood products

Contraindications

• individuals known to have anaphylactic or severe systemic reaction to human globulin

• newborn infants

Precautions

• observe patient at least 20 minutes after injection

Postpartum administration• Rh- mom has an Rh+ baby• fetal bleed screen• Pharmacy will deliver RhoGam med,RhoGam Injection Request

Form,Pharmacy Med Form• fill out Blood Bank,Pharmacy forms,and RhoGam injection

control form• identify patient with another nurse• educate patient,give RhoGam card• administer med• observe at least 20 min for any reaction• send appropriate documents to Blood Bank and Pharmacy

RhoGam and other vaccines

• Vaccines• given so the body will make antibodies to the

offending agent and protect the patient from future infection

• RhoGam• given to prevent the body from making

antibodies after being exposed to Rh+ blood

• if the body makes its own antibodies to Rh+ blood(in an Rh- person)the body will react to the Rh+ blood as if it is foreign,so it will attack any Rh+ blood administered,or any future fetus

• Rhogam is given to trick the body so it won't make its own antibodies.

• Giving a vaccine won't be a good idea,because we give vaccines hoping the patient will make antibodies and if they just had a dose of RhoGam,they shouldn't be making antibodies.

2 Alternatives

• withold the vaccines for a few months• give the vaccines,instruct patient to check

titers later to see if it worked• it wouldn't hurt to give it,it just might not

work

• IT IS NEVER APPROPRIATE TO WITHOLD RHOGAM,vaccines can be given later,but RhoGam has a narrow window to be administered.