Karina, I agree that it is best to keep your options open. I am also sure that under current IR laws every employee has the right to return to work part-time after maternity leave for at least a year. This would be worth checking.

With regards to child care, I reluctantly returned to work when DS#1 was 7 months. He took to child care really well and I have since decided (after wathcing numerous other children start at the day care centre) that most kids adjust better if they start before 12 months of age. Just something to consider. HTH. Good luck!!