Rh isoimmunization &

Hemolytic disease of newborn

Done by : Interns of group DMCH , Makkah , Saudi Arabia

Isoimmunization occurs when a woman produces Antibodies directed against foreign RBC surface Antigens , often those of her fetus.

DEFINITION

RH ISOIMMUNIZATION &

HEMOLYTIC DISEASE OF NEWBORN

CASE:A 34 years old patient PG , at 9 weeks gestation .

She came to ER complain of abdominal pain and

vaginal bleeding .

A urine pregnancy test was positive 3 weeks ago.

She denies passage of any tissue vaginally .

On examination the cx was dilated .

Investigation reveals that the pt is anemic and

blood type of B-ve and indirect coombs test (AAT) is

negative The patient admitted and prepared for

emergency D/C

What is the most important thing should given to

this patient before discharge?.

WHAT IS THE CAUSES!!?

The most common cause of

Isoimmunization is

FETO-MATERNAL BLEEDING

PATHOPHYSIOLOGYWhen any foreign RBCs comes to the mother , her lymphocytes get activated to produce Antibodies which will destroy those RBCs, and the mother will be (RH Sensitized).

Actually , that is not a problem in the initial pregnancy ,,, But if she get pregnant again with RH +ve fetus , Those Abs will cross the placenta and start destroying fetal blood cells causing hemolysis .

PATHOPHYSIOLOGYThe baby gets Anemic , RES activated , liver & spleen & BM get enlarged ,causing increasing in immature RBCs (erythroblasts).

The hemolysis continue and the RES can not handle it any more so complications presents.

OUTCOMES

The outcomes will varies from:• Mild Anemia and Jaundice .• Severe jaundice and kernicterus.• As severe as erythroblastosis

Fetalis and death in utero..

PATHOPHYSIOLOGY

And this is what it called

Hemolytic Disease of the newborn(HDN)

CAUSE!! Maternal

Fetal

1st exposure

CAUSE!! Maternal

Fetal

2nd exposure

Fetal red blood cells antibodies attack hemolysis

WHY IS HEMOLYTIC DISEASE OF THE NEWBORN A CONCERN ?

WHAT IS HYDROPES FETALIS ?

What is the risk of

ABO incompatibility On the risk of

Isoimmunization ?

They protects against it ..

ABO incompatibility protects against isoimmunization

Anti A

Anti B

Anti B

Anti A

O Blood Type AB Blood TypeB Blood TypeA Blood Type

A+

B+

A+

B+

A+

B+

A+

B+

Completeprotection

Partialprotection

Partialprotection

Noprotection

Anti A

Anti B

Anti B

Anti A

Rh –ve mother

Rh +ve husband Rh –ve husband

antibody

Anti-D

treatment

-ve+ve

HOW TO MANAGE HDN

1) Is the fetus at risk?2) Is the fetus anemic?3) Is the anemia severe enough so

we need to intervene?

1 )Is the fetus at risk?

5 factors must be present :1) Is mother Ag –ve ?2) Is father Ag +ve ?3) Are AAT is +ve ?4) Are Ab associated with HDN ?5) Is Ab titer > 1:8 ?

Low titer

High titer

1 : 21 : 41 : 8 1 : 161 : 321 : 641 : 1281 : 2561 : 5121 : 10241 : 20481 : 4096

Negligible

Significant

2 )Is the fetus Anemic?

3 investigation :1) Amniocentesis looking for

amniotic fluid bilirubin.2) Cordocentesis looking for fetal

hematocrit.3) U/S looking for MCA peak

velocity.

Amniocentesis

cordocentesis

MCA peak velocity

3 )Is intervention needed?

1) Amniocentesis : bilirubin in zone III.

2) Cordocentesis : HCT < 25 .3) U/S : MCA peak velocity is high.

According to GA :If < than 34 weeks gestation : IUT.If > than 34 weeks gestation : Delivery.

INTERVENTIONS

HOW TO PREVENT? By giving Anti D Ig ( RhoGAM ) .It is passively injected IM and it lysis any (D+ RBCs) before lymphocytes activated.We give it routinely at 28 weeks gestation to any (Rh-ve) mother . And after delivery if the fetus is (Rh+ve).Additional dose in special times mainly after CVS , amniocentesis , abortions , D&C ectopic preg. , APH , ECV .

Maternal Fetal

anti-D

WHAT IS THE MECHANISM OF ACTION OF ANTI –D ?

ANTI –D .…

routineFMH300 MCG

KLEIHAUER TEST

FOR 15 ML FETAL RED BLOOD CELL

KLEIHAUER-BETKE SMEAR

EVIDENCE BASED MEDICINE

What is the indications of giving anti-DOn evidence based medicine ?

ALL RECOMMENDATIONS ARE LASTLY

UPDATED AT 14-2-2014

RECOMMENDATION

• All Rh(D)-negative pregnant women should undergo an antibody screen at the first prenatal visit. If the initial screen is negative, a routine repeat screen at 28 weeks of gestation is optional.

RECOMMENDATION

The following recommendations apply to women who are Rh(D)-negative and whose fetus is, or may be, Rh(D)-positive:

We recommend routine administration of anti-D immune globulin early in the third trimester . The optimum dose regimen in the United States is 300 micrograms at 28 weeks of gestation. This practice reduces the incidence of antenatal isoimmunization from 2 to 0.1 %.

RECOMMENDATION

We recommend administration of antenatal anti-D immune globulin when there is an increased risk of fetomaternal hemorrhage. Some examples include miscarriage, abortion, ectopic pregnancy, multifetal reduction, amniocentesis, chorionic villus sampling, blunt abdominal trauma, external cephalic version, antepartum bleeding, and fetal death. We administer 300 micrograms.

RECOMMENDATION

Repeat dosing for situations where there may be an ongoing risk for fetomaternal hemorrhage (such as chronic placental abruption or placenta previa with intermittent vaginal bleeding) can be managed with serial determinations of the maternal indirect Coombs every three weeks with repeat dosing if it is found to be negative.

We recommend administration of anti-D immune globulin within 72 hours of delivery of an Rh(D)-positive infant. We administer 300 micrograms and also test for excessive fetomaternal hemorrhage in case additional doses are needed.

If anti-D immune globulin is inadvertently omitted after delivery, we recommend giving it as soon as possible after recognition of the omission . Partial protection is afforded with administration within 13 days of the birth, and there may be an effect as late as 28 days after delivery.

. 

RECOMMENDATION

within 72 hours of delivery to a postpartum nonsensitized Rh-negative

woman.

all Rh-negative nonsensitized women at 28

week of gestation.

INDICATIONS OF ANTI-D

Bleeding Early :

ectopic pregnancyAbortion

Molar pregnancy APH:

Placenta breviaAbruptio placenta

Vasa brevia

invasive prenatal

procedures

amniocentesis chorion villus

samplingfetal blood sampling

external version of the fetus

abdominal trauuma

At riskRoutine

WHAT IS THE INDICATIONS OF ANTI-D ?

Thank

you