Rh negative pregnancies can lead to isoimmunization of the mother if she has a Rh positive baby. This occurs due to a fetomaternal hemorrhage which allows the fetus's Rh positive blood cells to enter the mother's circulation and trigger an immune response. Testing for isoimmunization involves indirect Coombs testing of the mother. Unsensitized Rh negative mothers receive anti-D immunoglobulin injections to prevent isoimmunization. Sensitized pregnancies require careful monitoring and may involve amniocentesis, intrauterine transfusions or early delivery to prevent fetal complications like hydrops fetalis. The baby may also require treatments like phototherapy or exchange transfusion if affected by hemolytic anemia or

1. Rh NEGATIVE
PREGNANCY
Dr shweta

2. Contents
 Introduction.
 Pathophysiology.
 Isoimmunisation.
 Diagnosis.
 Management.
 Effect on fetus.

3. INTRODUCTION
 Rh factor discovered by Landsteiner in
1937.
 Protein antigen of red cell membrane.
 5% of pregnancies are Rh-ve.
 Inherited as Mendelian dominant.
 common cause of perinatal mortality in
babies of Rh-ve mothers.

4. PATHOPHYSIOLOGY
 Mother is Rh-ve with a Rh+ve foetus.
 Mother is having anti Rh antibodies.
 Antibodies cross placenta to foetus.
 Foetal Rh+ve red blood cells get
hemolysed.
 Foetus suffers from severe anaemia
leading to cardiac failure,oedema and
death.

5. CAUSES FOR ISOIMMUNISATION
OF THE MOTHER
 Previous Rh+ve fetus with isoimmunisation
due to foeto-maternal haemorrhage.
 May be full term delivery, abortion,
ectopic or partial mole.
 Previous Rh+ve blood transfusion.

6. ISOIMMUNISATION
 Cause-foetomaternal haemorrhage.
 Maternal blood produces large number of
antibodies in response to small amount of
foetal blood.
 Amount of foetal blood required to cause
isoimmunisation-0.1ml.
 Antibodies thus formed in maternal blood
stays lifelong.

7. contd
 Usual fetomaternal Hge- <4ml.
 If no prophylaxis- sensitization in next
pregnancy-16%.

8. DIAGNOSIS
 Routine blood grouping and typing for all
antenatal mothers on 1st
visit.
 If Rh-ve-, husband’s blood group.
 If negative-normal pregnancy.
 If positive-indirect Coomb’s test to look for
isoimmunisation at 24 weeks.
 If negative for antibodies-treat as
nonisoimmunised Rh-ve pregnancy.

9. INDIRECT COOMB’S TEST(ICT)
 Done in Rh-ve antenatal mothers with a
Rh+ve husband.
 Timing-24 weeks.
 Detects incomplete IgG antibodies which
can cross placenta.
 Done with Coomb’s serum containing
antiglobulin antibodies.

10. MANAGEMENT OF ICT-VE
 Anti D prophylaxis-at 28 weeks.
 After delivery if needed.
 Prevent anaemia.
 Arrange donors before delivery.
 Ensuring availability of blood in bank.
 Quick clamping of cord.
 Send cord blood for testing.
 Neonatal care facility.

11. CORD BLOOD TESTS
 Blood grouping and typing.
 Direct Coomb’s test.
 Bilirubin,Hb and haematocrit to detect
haemolysis,anaemia and jaundice.

12. ANTI D PROPHYLAXIS
 Anti D immunoglobulin is administered to
neutralise the Rh+ve blood which enters maternal
circulation.
 Sensitisation in next reduced to 1.6% compared to
16% if not given.
 These antibodies disappear from blood within
some time.

13. TIMING
 Within 72 hours of delivery if baby blood
group is Rh+ve and DCT-ve.
 After 1st
trimester pregnancy loss.
 After invasive procedures-
amniocentesis,chorionic villus
sampling,cordocentesis.
 Antenatal-at 28 weeks.
 Also in 2nd
,3rd
trimester APH,ECV.

14. DOSE AND ROUTE
 Route-intramuscular injection.
 Dose-300µgm of anti D immunoglubulin.
 Neutralises 15ml of foetal RBC or 30ml of
blood.
 Higher dose required for larger FMH.
 Assessed by Kleihauer Betke test.

15. LARGE FMH
 Traumatic delivery.
 Abruption.
 Manual removal of placenta.
 Stillbirth,IUD.
 Twins.
 Hydrops fetalis.

16. KLEIHAUER BETKE TEST
 To assess amount of FMH.
 Acid elution test which detects foetal
haemoglobin.
 Amount of foetal blood in ml=
maternal blood vol x maternal hct X KB
cells/ fetal hct.

17. NONRESPONSE
 Immunologic nonresponder.
 Co-existing ABO incompatibility.
 Insufficient sensitising volume.

18. FOETAL EFFECT
 Mild effect-haemolytic anaemia of the
newborn.
 Moderate-effect-icterus gravis
neonatorum.
 Severe effect-hydrops foetalis.

19. CONGENITAL HAEMOLYTIC
ANAEMIA
 Anaemia develops slowly in first few
weeks.
 Jaundice is not evident.
 Haemolysis continues for 6 weeks after
which antibodies cease to exist.

20. ICTERUS GRAVIS NEONATORUM
 Baby not jaundiced at birth.
 Develops so within 24 hours.
 Effect starts after cord clamping as
excretion through placenta stops and
premature liver enzymes.
 If serum bilirubin >20mg/dl-crosses blood
brain barrier-kernicterus(damage of basal
ganglia).

21. HYDROPS FOETALIS
 Severe haemolysis.
 Anaemia causes heart failure.
 Compensatory placental hyperplasia.
 Liver damage causing hypoprotinemia
 Oedema,hydrothorax,ascites.
 Stillborn or dies soon after.
 USG-Buddha foetus-for scalp edema.

22. MANAGEMENT OF
ISOIMMUNISED PREGNANCY
 Critical titer of Ab-1:16 to 1:32.
 If ICT +ve-titer at 1st
visit-monthly.
 If below critical level-deliver at term.
 If >CL-if mature lungs-delivery.
 If immature lungs-glucocorticoids.
 If below 36weeks-amniocentesis and
bilirubin estimation.

23. Contd
 High titer or multiple isoimmunised
pregnancy or previous history of EF-
amniocentesis,bilirubin estimation at
OD450.
 Plot it in Liley’s graph as zones 1,2 or 3 with
zone 3 as most severe.
 Zone1-deliver at term.
 Zone 2-repeat titer after 2 weeks.
 Zone 3-cordocentesis and IUT.

24. CORDOCENTESIS
 Under USG guidance.
 0.5 to 2 ml collected from umbilical vein.
 Risk of abortion,preterm labour,IUD.
 Test for foetal haematocrit and bilirubin.

25. FOETAL MONITORING
 USG-polyhydramnios/foetal hyrops
though a late finding.
 Amniocentesis and Liley graph plotting-
from 26 weeks.
 Middle cerebral artery peak systolic
velocity-18 weeks onwards.

26. INTRAUTERINE TRANSFUSION
 Based on –Hct,amniocentesis or MCA-
PCV.
 Route-intravascular(portal/umbilical
vein),intraperitoneal.
 Blood-fresh O-ve packed cells.
 Amount based on gestational age or
Nicolaide’s formula.

27. TREATMENT OF BABY
 Phototherapy-with blue light with
protection of eye and genitalia from
exposure.
 Phenobarbitone.
 Exchange transfusion.

28. EXCHANGE TRANSFUSION
 INDICATIONS-cord Hb<10gm/dl
cord bil>5mg/dl
rising rate>1mg/dl/hr
 Aim –to correct anaemia,to remove
antibodies and bilirubin.
 Route-umbilical vein by push and pull
technique.
 Watch for hypoglycemia,
hypocalcimea,metabolic acidosis.

29. Conclusion
 Rh negative pregnancy should be
thoroughly investigated to rule out
adverse effects on the mother and the
fetus.

30. THANK YOU