1. Rheusus iso-Immunization
Definition :
It is an immunological disorder that occur in a pregnant Rh-ve patient carrying an Rh+ve fetus . The immunological system in the mother is stimulated to produce antibodies to Rh-antigen , which then cross the placenta and destroy fetal RBCs .

2. Pathophysiology :
The pathophysiolog of Rh- isommunization occur as following :
During normal pregnancy the fetal blood may enter the maternal circulation ( fetomaternal hg ) in small amount , it is demonstrated throughout normal pregnancy and at the time of delivery occurs ( in large amount ( 15 – 30 ml )) .
And the critical sensitization volume is 0.1 ml of fetal RBCs to stimulate maternal immune system

3. Potential sensitizing events for Rh disease
. miscarriage .
2. termination of pregnancy .
3. Anterpartum haemorrhage .
4. Delivery ( normal vag. Delivery or C/S ) .
5. External cephalic version , invasive prenatal testing ( chorion villous sampling , amniocentesis and cordocentesis )
6. Fetal loss ( IUD ) .
7. Fetal reduction .
8. Ectopic pregnancy .
9. Abdominal trauma .
10. Rh+ve platelet transfusion .
11. Manual delivery of placenta .

4. Factors determined the occurrence of Rh-Isoimmuization :
1. Presence of Rh+ve fetus inside Rh-ve mother .
2. Whether the process of immunization is initiated in the mother or not .
3. ABO blood group compatibility between the fetus and the mother , if incompatible the fetal cells will be destroyed rapidly and no immunization will occur .
4. Variable antigenicity and variable maternal response to Ag.
5. Efficacy of placental passage .
6. Quantity and subclasses of antibodies screated .

5. Clinical features of fetus with Rh-iso immunization
1. Hydropis fetalis .
2. Large placenta and oedematous .
3. Polydramnious .
4. Large fetal heart .
5. Decrease fetal movement .
6. Abnormal fetal cardiotocography(CTG) with reduced variability and eventually a sinusoidal trace .
7. Hyper dynamic fetal circulation ; can be detected by Doppler U/S by measuring increasing velocity in middle cerebral artery and aorta
8. Hepato-spleenomegaly .
9 . Mid-trimester recurrent miscarriage or still birth .
10. The baby has jaundice within the first 24 hrs post delivery and may kernicterus , cerebral palsy and convulsions .

6. Prevention :
*By administration of anti-D Ig to a non-sensitized Rh-ve woman within 72 hrs following the delivery of Rh +ve infant *. Give anti-D Ig (300 microgram ( I.M. ) as a prophlyaxis ) at 28 – 34 wks of gestation

7. Prevention
* Proper cross matching at any blood transfusion * ABO grouping and Rh factor should be known for every pregnant for her and her partner
*. 250 IU of anti D Ig if Rh D+ve platelet transfusion

8. Prevention
* Ectopic pregnancy - *Spontaneous abortion Therapeutic *Termination of pregnancy - *Threatened abortion

9. The spectrum of Rh diseases :
1. Normal delivery at term , mild jaundice requiring phototherapy .
2. Preterm delivery of an anemic fetus requiring exchange transfusion .
3. Delivery of fetus at 34 wks of gestation following fortnightly blood transfusion from 26 wks of gestation .
4. Still birth or neonatal death .

10. Detection of fetal RBCs in maternal circulation
*. Detection of Abs in maternal circulation . *Kleihauer – Betke tes.
*Agglutination test to detect IgG , IgM *Antiglobin test .
* Coomb's test ( direct and indirect ) *Measurement of Anti D antibody level in IU / ml in maternal blood with critical level >= 4IU/ ML .

11. Management of Pregnant lady that is Rh-ve
- History of present preg. and previous preg. ( any previous Rh disease and it's severity and the time of it's occurrence ( GA ) and neonatal outcome , BL. Group of her husband and Rh and the zygostiy if possible , any basal records of indirect coomb's test you can depend on it , and according to his result can divide the pat. To :
a. Rh-ve non-immunized ( comb's test – ve )
b. Rh-ve immunized ( comb's test + ve ) .

12. Management of Rh-ve non-immunized
aim of management is to prevent the formation of Abs in maternal circulation , by giving Anti D Ig injections antinatally before or shortly after the exposure to Rh+ve fetal RBCs ( sensitized event ) and prophylactically at 28-34wks of gestation , and postnatal with 72 hr of birth of Rh+ve baby300 microgram = standard dose ) if suspected more than 30 ml FMH ---- so do Kleihauer test .

13. Management of Rh-ve non-immunized
, and repeat Ab titer after 1st one at monthly interval , to ensure the ongoing status of a non-sensitization , also repeat the titer 3-6 months after birth to detect any failure of protection .Need Anti- D Ig after each delivery of each subsequent Rh+ ve baby