How much time you need to take off depends on:
- when in the academic year your baby is due
- whether you have an uneventful pregnancy (if, for example, you get hyperemisis you probably don't want to be studying!)
- The structure and format of yoru degree
When I started uni, I had a 1.5 month old. Like you, I had a choice of having a baby in my mid thirties or hanging on and having a baby in my late 30s.
I decided to go for it, as I thought it was too much of a risk to wait till my mid-30s as I might find I'd missed my chance. Also the age gap would be huge if I waited.
So I tried to have a baby due in the summer holidays between 2nd and 3rd year - but what actually happened was I had a baby due April. I proposed to my uni that I leave after semester one of my third year, then go back a year later to do semester 2.
My course leader said she thought that wasn't a good idea as the field I was studying moves so quickly, the degree changes most years, so it'd be very disjointed to try to put semesters from two years together. If I had been doing a subject that doesn't change much, this would have been possible, however.
So, she suggested I intermitted for two years, so that's what I did. I took the whole year of my pregnancy off and the whole of the following year.
I suspect that is a rather extreme example however! At the other extreme, a friend got pregnant in her final year, also due in April. Her course was mostly exam based. She got all her coursework done before the deadlines and revised like mad. Then took time out until her exams, turned up for the exams with her partner looking after their baby while she sat them. This worked for her as her baby was mix fed and because it worked with her course.
More generally, it's not easy, but if you want another baby and this is your best bet, you will find a way to make it work.
My top tip is to work your socks off in the first year. The uni bent over backwards to accommodate me and I suspect a little of that might have been as I was one of the top students on my course, they didn't want to lose me!
Just FYI, the word "defer" means to put off your course before you even start. But if you take a break and come back, it's called "intermitting".