My wife started cutting herself when pregnant with our second child, the whole pregnancy was angry and violent?

My wife has Borderline personality disorder. We have two sons 18 months apart at birth. The first pregnancy was a joy. The second, she started "cutting" and doing "knifeplay". She spat in my face and would punch me and just be angry and mody and violent with our ond child. When the second child was two years old, she begab to cheat on me sporadically for the next 8 years. i just found all of this out and am leaving her. She has told me of numerous affairs, but says that no cheating started until after our youngest was two years old. She picked the times we had each child. She took body temps to check for ovulation..maily on the first one. I wonder if she was cheating then and was unsure whose child she was carrying, mine or someone elses. Granted, she is a cutter to this day, but it started back during the second pregnancy. Motherhood can aggravate BPD as being a "mother" is something the inner child resists wanting to be. She wanted to go to any low paying job just to get away from the child. She stayed home for two years and looked horrid and her eyes were black from being a stay at home mom. She got a job abd cheated witha homeless guy that lived in his car and was an IV drug user. She has no idea of the world, but I have known a few recovered heroin users. How different can one pregnancy be versus another emotionally and hormonally? Part of her Borderline Personality Disorder makes her "split" the way she feels about people closest to her. From adoration to spite and hatred for no real reason. I have always been good to her, but this is the point where her disorder first went severe. It was our 4th year of marriage. Could it be that she has aboted in the past and raged over being torn now having a child that she delivered? She is a serial cheater and serial liar. Again, i am leaving her this month and I have the kids 9 months out of the year. She is finally diagnosed properly and undergoing therapy. i wish her well, but she has cheated and I am forced to question paternity (though it bears no difference in my mind, these are my boys no matter what). Can pregnancy make you that crazy without a disorder?