I returned to work after 14 months leave (inc holiday) when dc1 was 13 months. Two days in I discovered I was pregnant with dc2, worked for 8.5 months and now on mat leave again.
I can't say it was an easy decision and management/my team certainly didnt take it very well, but everyone soon got used to the idea and although its scary o take two leaves so close together, IMO it suis me better.
I am getting the hard, baby/childcare years done early and close together enough for me to still be young enough to get back into my career (am 30) and go for promotion etc once dc2 is 1.
The way I also see it is I am a damn hard worker when I am there, have been with the company many years and a company wouldn't factor in your loyalty to them if they had cuts/redundancies to make, so why should I pause having a family for them?
I plan to stop at two children, be back at work by 31 and resume working FT, so the way I see it, what difference would it make if I waited 1-2 years after mat leave 1 before getting pg again. Is far better for me to get both done out the way so I can get back to work quicker.