<human>: Condense the text into a few key points

I have no idea if this is the right sub to post in, but I'll give it a shot. 

I live on Ontario, Canada. My boyfriend has worked Toyota for 2.5 years. March will be 3 years, and it will be when we have our child. I plan to take the given 15 weeks maternity leave and I would like my boyfriend to be around for atleast the first month. 

Toyota goes by 3 month contracts when you aren't hired on, renewing it every 3 months. Assuming he isn't hired on yet in March, he is allowed to take the leave but has to return within the 3 months. 

To my question: can Toyota be unreasonable and not renew his contract if he takes time off? Or does it go hand in hand with firing a pregnant woman, which is hard to get around.
<bot>: can Toyota indirectly use paternal leave to not renew your contract? (No other issue as an employee ie., write ups etc. )