Rhesus Disease

Every individual is born with a certain blood type (A, AB, B, or O) and all blood are either Rhesus positive or Rhesus negative. About 85% are born with the Rhesus factor in their blood being Rh positive. This means their blood contains the Rhesus factor. However some 15% or 1 out of 6 people are rhesus negative. A pregnancy becomes a problem if the mother is rhesus negative and she is carrying a rhesus positive baby.

Causes of Rhesus Incompatibility

• In your routine blood test, you will be tested on the Rhesus factor. It only becomes an issue if the woman is Rhesus negative and the man is Rhesus positive
• Rhesus positive blood cells are equipped to generate antibodies to fight alien blood cells
• Rhesus negative blood lacks the antigen that is able to produce antibodies
• If both parents are R-, danger level is nil as the baby will also be R-
• In the first pregnancy if the mother and child differ in the Rhesus factor (the mother is R- and the fetus is R+) the pregnancy will still go without a hitch because the maternal and fetal blood never mixes.
• During delivery however baby's blood may leak into the maternal blood, resulting in the woman to develop antibodies to attack the Rhesus positive cells.
• In the subsequent pregnancy if there is incompatibility in the Rhesus factor, the baby can become anemic
• After the first pregnancy, the mother's body still retains antibodies meant to destroy rhesus positive cells
• Remnant antibodies in the mother's body during her second pregnancy can cross the placenta of the second baby and destroy its red blood cells
• Once it enters into the fetus system, the antibodies will break down the fetal cells and give rise to complications like stillbirth, severe anemia, heart failure, severe jaundice, spasticity, or mental impairment
• If the antibodies are traceable during pregnancy, the baby can be saved while in the utero itself with a intrauterine blood transfusion
• A woman with Rhesus negative (R-) will need special care so that the antibodies produced in her previous pregnancy will not destroy the blood cells of the current growing fetus

The Symptoms

• A clear indicator of the disease is the presence of Anti-D antibodies in the mother's bloodstream
• Symptom can be mild - baby is mildly anemic
• Symptom can be severe - baby suffers heart failure while inside the womb
• Regular monitoring of baby through an ultrasound to keep a close watch on baby's progress will be performed
• Watching the blood flow to the baby's brain will be monitored
• If the blood flow is very high, the baby may be anemic
• The other possibility is to take the mother's blood sample to check if baby is rhesus positive or negative. In a R- mother, if the blood sample points to baby being R- as well then all is well

The Solution - Anti-D Injections

• The use of Anti-D injections has made Rhesus disease much rarer these days. More and more Rhesus negative women are being immunized soon after delivery
• Anti-D injection is a blood product
• The injections are given to serve as a preventive measure - basically to prevent the leakage of the fetal blood cells into the mother's bloodstream
• These injections are also given at week 28 of the pregnancy and after the birth of the Rhesus positive child. A fresh injection is given during and after each subsequent pregnancy to help destroy the antibodies (within 72 hours after the birth)
• The serum is of no use if given after the woman's body has already produced the antibodies.
• These injections prevent rhesus disease by destroying any fetal cells before its entry into the mother's system so that the mother has no chance of producing antibodies
• Anti-D is also given to Rh negative women after the incidence of abortion, miscarriage, threatened miscarriage if they occur after the first trimester.
• Rh negative women who have suffered traumas to the abdomen in the form of accidents or falls are also given Anti-D shots
• A Rh negative mother who has undergone invasive procedures such as CVS, amnio, cordocentesis must be given anti-D gamma globulin injections following the test(s)

Treatment before & after the Birth

• A baby with rhesus disease can receive an intrauterine blood transfusion before it is born to completely eradicate the antibodies. First a blood sample from the umbilical cord will be taken and examined to confirm if baby is anemic
• If anemia is confirmed, baby will be transfused repeatedly if necessary until she develops enough for delivery
• Treatment after birth will depend on the severity of the anemia and jaundice in baby
• In mild cases of jaundice, bilirubin levels may respond to phototherapy or light therapy
• In the more severe cases, an exchange blood transfusion may be necessary