Any lawyer types out there that can help?

sparks4stp

So just a quick backstory. My boss is an a hole. When he found out I was pregnant the next day he freaked out on me and called me an a hole 5 times and threatened my job for refusing to restrain a super aggressive cat with just a towel. I'm a vet tech. He was really upset about me getting pregnant because we had just lost a part time employee due to her having to take care of her mom with breast cancer. And I know he was hoping to get by without hiring anyone even though we are already understaffed. This man has no compassion and in the past has told employees to consider abortions because they were young and unmarried and just recently told a another woman here who suffered a miscarriage that its because women take pregnancy tests too early. She was 8 weeks along and in our line of work we need to notify our employer ASAP because of on the job risks.
Anyways...just recently he decided to switch the company he uses for the simple Ira plan he offers. This is stated in the employee handbook as being offered to all full time employees that have been here at least 2 years. I've been here close to 7 and have always been offered the option in the past. I've never taken advantage if it because of the poor feedback from my coworkers regarding the plan. But he passed out the paperwork a week ago to everyone else on my day off and I got nothing. He showed up today to collect the paperwork from people while I was in the lab doing something so I wasn't there when he was discussing it. He hasn't even mentioned it to me. Back when I got pregnant I had said to him I was considering going part time after maternity leave but thus won't be until at least November. My question is...can he strip me of my full time benefits while I am still full time??