Rhesus disease (Rh incompatibility; Rh factor disease; haemolytic disease of the foetus and newborn; HDFN)

• What is Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)
• Statistics on Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)
• Risk Factors for Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)
• Progression of Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)
• Symptoms of Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)
• Clinical Examination of Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)
• How is Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn) Diagnosed?
• Prognosis of Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)
• How is Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn) Treated?
• Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn) References

What is Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)

Rhesus disease (or Rh incompatibility) is a condition that results when a female of Rh-negative blood is exposed to Rh-positive blood cells and subsequently her body creates Rh antibodies to remove what it sees as an invading organism.
In the case of a pregnancy, if blood is shared amongst fetus and mother, the mothers antibodies will attach and attack the foetal red blood cells, leading to anaemia in the foetus. This is known as Haemolytic Disease of the Newborn.
The Rh Factor is a blood cell based surface antigen that was named in recognition of the monkeys in which it was first discovered.

Statistics on Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)

Figures tend to indicate that 15% of the population on average are considered Rh negative, meaning that 85% of the population are considered Rh positive.
Approxiamately 1 in 1000 births are considered succeptible to Rhesus disease.

Risk Factors for Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)

There are two ways Rhesus disease can occur. The first involves a Rh-negative mother being exposed to a Rh-positive foetus during the period of her preganancy.
If an Rh negative woman has a baby that is Rh positive, then it is possible for some of the baby’s blood to enter into her system. This can happen under several circumstances:

• During the birth,
• Naturally (between 28 weeks and delivery),
• During an amniocentesis,
• At an abortion,
• When a miscarriage occurs.

The condition can also occur during the course of a women receiving a Rh-positive blood transfusion.
The passing of Rh-positive foetal red cells into the maternal circulation sensitises the mother to form antibodies to the Rh antigen. Sensitisation does not pose a problem, however, if anti-Rh crosses the placenta to the foetus during the next pregnancy with an Rh-positive foetus, it will coat the foetal red cells with antibody and result in reticuloendothelial system destruction of the cells, causing anaemia and jaundice.

Progression of Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)

If affected, the newborn infant may be born with either mild, moderate or severe forms of the disease.

How is Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn) Diagnosed?

Diagnosis is made on the baby’s symptoms, such as jaundice and anaemia. The mother’s blood group is also important in diagnosis.

Prognosis of Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn)

The Rh negative women is at no risk, as the antibodies simply remain in her body for the remainder of her life, it is only the potential for childbirth that raises any risks.
Newborn survial rate can be anywhere between 70-100% depending of available care.

How is Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn) Treated?

Rhesus-negative women can be prevented from developing antibodies by being given an injection of ‘anti-D gamma globulin’ within 60 hours of the birth of a rhesus-positive baby. In order to protect future babies, this is done in all such cases. Once a woman is sensitised to the D-rhesus antigen, anti-D globulin can have no effect. So in essence the antibodies won’t have any effect on the fetus or newborn.
The injection is also given after a termination of pregnancy, or if there is any other reason to believe that a rhesus-negative mother’s blood may have come into contact with a rhesus-positive baby.

Rhesus disease (Rh incompatibility, Rh factor disease, Haemolytic Disease of the Newborn) References

[1] American College of Obstetricians and Gynecologists: Management of isoimmunization in pregnancy. ACOG Technical Bulletin 148; 1990.
[2] American College of Obstetricians and Gynecologists: Prevention of D isoimmunization. ACOG Technical Bulletin 147; 1990.
[3] emedicine
[4] Hoffbrand, A.V, Pettit, J.E, & Moss, P.A.H. 2001, Essential Haematology, Blackwell Science, Oxford.
[5] Peterec SM: Management of neonatal Rh disease. Clin Perinatol 1995 Sep; 22(3): 561-92