Rh Incompatibility

                                                              (Rh Disease)

                                             "Haemolytic disease of fetus and newborn"

Rh is an abbreviation of  Rhesus. ISOIMMUNIZATION Rh incompatibility - A blood incompatibility between mother and fetus is affected.A mixture of maternal and fetal blood. Usually only affects  2nd of greater pregnancies. 

Introduction

When an Rh negative woman is pregnant with Rh positive child, she may be exposed to the Rh antigen (foreign to her body) during delivery or in an  event of miscarriage. As a response to this  the woman develops antibodies to Rh antigen,. If the woman is pregnant next time with an Rh positive baby,  the antibodies she had developed may enter the fetus and attack the Rh antigen in the fetus RBC's (red blood cells) leading to a condition known as Hemolytic Disease of the Newborn, causing the baby to have anemia, heart failour and jaundice..

Rh incompatibility is a condition which develops when an Rh negative mother concieves a fetus which is Rh positive.

Fetal RBC Rh Antigen : Rh "D" Ag

Mother produces Anti Rh (D) Abc

Isoimmunisation :

When the mother produces Abs directed against fetus RBC surface Ag

Cause

Feto-maternal Bleed :

Risk Factors of Feto- maternal Bleed :

• Amniocentesis

• Ectopic Pregnancy

Erythroblastosis fetalis or  Hemolytic Disease of Newborn (HDN) found due to Rh Incompatibility:

It usually occurs in fetus but can also occur in neonates. It is the type of anemia in which the red blood cells of the fetus are destroyed by maternal antibodies in an immune response targeted against the fetus. It occurs due to Rh incompatibility. As a result baby can suffer from severe anemia, brain damage and even death.

Causes

Etiology & Pathogenesis

Significant hemolysis occurring in the first pregnancy indicates prior maternal exposure to Rh positive R.B.C

• Fetal blood associated with a previous spontaneous or therapeutic abortion
• Ectopic pregnancy
• Amniocentesis.
• Percutenous umbilical blood sampling.
• Placental l separation
• A variety of different prenatal procedures.  i.e Amniocentesis.
• Blood transfusion : Transfusion of some other blood products containing Rh D R.B.C in an Rh-negative mother

How the child  and the family are affected long term ?

Hemolytic disease of the Newborn (HDN) is the difficult condition to battle. Babies with HDN may need to be placed in an incubator or require ventilator assistance immediately and blood transfusion after birth.  As they get older, they can suffer from neuro-developmental abnormalities, including deafness,blindness, speech impairment and even cerebral palsy. Consequently they may require speech therapy, occupational therapy and rehabilitation to improve their quality of life.

Care during pregnancy

Developing antibodies to Rh positive blood can affect further pregnancies and must not be ignored. While planing to expand the family. Pregnant woman with Rh negative blood type are likely to require extra attention during pregnancy, owing to high probability of sensitization occurring. Doctor should discuss management of options with parents, once a risk is discovered. The mother should be offered Rh immunoglobulin as prophylaxis and at any event where they could to be sensitized (such as invasive test or abdominal trauma). Lastly, both mother and baby can benefit from close monitoring.

While this condition may be unavoidable having information on  the situation can be very helpful in  early reorganization of Rh incompatibility. This can allow doctors to take all necessary steps to treat any complications. As the saying goes "A stitch in time saves nine."

Symptoms

It can cause symptoms ranging from mild to fatal.

1. Hemolysis. Anemia, 
2. Hepatosleenomegaly
3. Jaundice occur within 48 hours of birth
4. Total body swelling Hydrops Fetalis
5. Respiratory distress
6. Kernicterus
7. Poor feeding 
8. Decrease activity

Diagnosis

Ultrasound :

Prevention

• Vaginal delivery preferred.
• Premarital counselling
• Proper management of unsensitized Rh negative pregnancies.
• Proper matching of blood in transfusions particularly in women before childbearing .
• Blood grouping must for every women, before first pregnancy.
• On exposure to Rh positive blood Anti Rh Immunoglobulin should be given as early as possible.

Treatment

• Your baby will be monitored with  ultrasound to look for signs of anemia. (Hydrops fetalis)
• If antibodies are present and anemia is detected in the fetus, the blood transfusion is performed to replace the fetus blood supply with Rh negative blood which will not be damaged by the antibodies your body has created.
• Intrauterine transfusion : The transfusion is administered through the umbilical cord while the fetus is still in the uterus beginning at 18th week of pregnancy or beyond. 
• Early delivery : The procedure can be somewhat risky so some surgeon prefer to induce early labour. If cordocenthesis blood sample if Hb less than 10 gm/dl.
• The blood transfusion is than administered after the baby is born.
• Exchange Transfusion : The procedure is done slowly, removing the newborn's blood and replacing it with fresh blood or plasma from a donor.
• Effects of Transfusion : Removal of bilirubin, removal of sensitized RBC'S, and antibodies. suppression of incompatible erythropoisis.

Exchange Transfusion

• If Rh incompatibility is diagnosed during pregnancy, mother will recieve Rh Immunoglobin in seventh month of pregnancy again within 72 hours of delivery
• Mother may also receive immunoglobulin if the risk of blood transfer between mother and the baby is  high (for example miscarriage, ectopic pregnancy, or bleeding during pregnancy)
• Photo therapy :

Photo Therapy

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