Is Negative ICT Test For Rh Sensitization At 11th Week Of Pregnancy Conclusive?

Posted on Tue, 18 Jul 2017

Question: Hi Doctor... My wife is B negative and I am B positive. We have a 6 years old son who is B positive... We missed to take Anti-D injection during first pregnancy/post delivery. In-between she had a miscarriage 2years back as well.Now she is pregnant and we fear about Rh sensitivity.. We took ICT today (11 week now) and result says negative. Does it mean her blood has not got sensitised on both prior occasion and have not created antibodies to Rh positive. Or does it mean it is sensitized and if positive blood of fetus mix by any chance will immediately create antibody and start to quickly affect child inside, there is no use of antiD anymore. I am very much confused a quick reply on this is appreciated.

Answered by Dr. Prof. Kunal Saha (6 hours later)

Brief Answer:
Pathophysiology explained

Detailed Answer:
Thanks for asking on HealthcareMagic.

I have gone carefully through your query and understand your concerns. ICT or indirect Coombs test is a prenatal blood test that will let you and your doctor know whether your wife is Rh-negative or Rh-positive and to check whether her body is making Rh antibodies, which would indicate that the baby is Rh-positive. It is good to know that the reports are negative as of now. However, 11 weeks can be a bit too early and periodic follow up would be needed. If starts producing Rh antibodies, then Rh immunoglobulin (RhIg or anti-D, aka RhoGAM) would not help. Instead, her doctor will have to test your blood regularly to check the antibody levels. If they get high, she might need more tests to check on baby’s health.

Let me know if I could help further.

Regards

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Prof. Kunal Saha (1 hour later)

Hi Doctor, thanks for the answers.

1. Can I consider my wife blood is not sensitized during earlier pregnancy as the result of ICT shows negative. If yes, can the risk of opposite blood group is similar to the first pregnancy and does antiD work then which we usually give at 28 week

2. Does sensitised blood produce antibodies only when it get exposed to Rh positive blood of baby. Will it not have antibody within itself. If it will be available within itself, why report showed negative.

3. I understand if baby is Rh negative there is no problem.

4. If complications starts when should I think of termination

Answered by Dr. Prof. Kunal Saha (2 hours later)

Brief Answer:
You need to wait and watch. Do not presume things

Detailed Answer:
Thanks for writing back.

1. It does not indicate lack of previous sensitization. For the effect of the prior sensitization to occur, the baby has to be Rh positive. But if the baby is Rh negative no reaction will occur. If the baby is Rh positive but has not still developed the Rh positivity, the results can be negative as of now turning positive subsequently.

2. Yes, only when exposed to Rh positive blood. Antibodies are not present as reserves. They are manufactured as per requirement.

3. Yes, if the baby is Rh negative there would be no problems anyway.

4. No, that is not for you to decide. The conditions will dictate the situation. Even a Rh positive baby can be delivered live. A condition called erythroblastosis fetalis (which needs to be managed) may develop as a complication. If the baby can survive it, it can be absolutely normal subsequently. There are therapies like intrauterine blood exchange which can be done to avert such a situation (to save the baby). I would insist you to wait and watch.

Regards

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar