Would you leave him over his vicious pets?

First, I am an animal lover. I have volunteered with rescue groups for the past 15 years. Our love of animals was one of our mutual attractions a year ago.He has 1 Pitt bull, 2 Pitt mixes and a small dog. At first, I liked his dogs. Then, the big dogs started escalating bad behavior as they approached 2 years old: breaking out/destroying crates, destroying furniture, chewing shoes, etc. 
Recently, I was alone one night and let the group outside to pee. The Pitt and 1 Pitt Mix turned on the other bigger dog and tried to kill her. I broke up the dog fight. Covered in blood, I helped nurse a ripped apart dog ear and throat. I sustained minor injuries in the attack. Later, he shared the same 2 dogs tried attacking again less successfully on the little dog and the recovering pup.
Now, he asked me to move in upon discovery that I'm 6 weeks pregnant. I don't want to move. I want to break up. I'm terrified of the dogs whose teeth marks scar my arms. He kept the two very dangerous aggressive dogs and has done no additional training. I won't even go in the house now.
Whether I go full term or miscarry (I've lost one before), I'm done. What would you do?