Can my ex-husband use an abortion against me during our custody battle?

Six months ago, I left my abusive ex-husband. I found out that I was pregnant after leaving him and I had an abortion. He found out 5 months later. He currently has our children after stating false allegations against me. He told the judge that I was an addict which is not true and after undergoing numerous evaluations, drug test and paperwork from doctors, I have proved that it was not true. Unfortunately, the abuse has not been brought up yet and my attorney says it won’t be until we go before the judge again to prove my husband was controlling, abusive, mentally unstable (he cut himself when i tried to leave, held me hostage, and more). We have mediation soon and if we can't come to an agreement (which I'm sure we won’t), we will be going to court again. Can the abortion be used against me? When I left my husband, he took everything. My house, car, children, clothing, money, etc. I was a stay at home mom for the past 4 years. I could not bear to have a child when I lost everything and am fighting for my children. I had to start from nothing. I currently have a job, home, car, etc. I'm so scared that the abortion I had will ruin my chances of my children coming home.