I took zoloft when I was pregnant with my last. He was 3 weeks premature and had vitamin deficiencies. I don't know if it was the zoloft or not. The natal nurses said no, but the doctor (not my gyn/ob, but her partner) said it was my fault for being weak. I was very suicidal during the pregnancy, which is why they put me back on zoloft.

A perinatal psychiatrist sounds like a good way to go.