anticardiolipin antibody

During my 3rd pregnancy I was tested for Lupus all tests came back negative except the anticardiolipin antibody which was IGg 29. I was told to take a baby aspirin a day and I did. After I delivered my daughter I was retested and it came back at 20. My question is can this antibody just appear during a pregnancy? Could it be possible that this can come and go. I have had 3 normal pregnancies and no clotting problems. My Dr's say don't worry, but I do. Thank you for any help in this matter, Ronnie

[CCF CARDIO MD JMF]

Dear Ronnie,

Pregnancy may cause changes in your immune status.  You should continue your aspirin and note this in the back of your mind but not worry about it.  If you do develope a clot in the future , in form your physician of this antibody.  In general.  we treat this with aspirin but do not have other therapies to prevent clots.