My PhD course is taught in week long crash courses, and you usually only take classes in the first year. My course is comprised of 5 modules - 2 of which I don't have to do as I've done them as part of my MA course and one runs 2 weeks after my due date so my supervisors have said I can take that in 2nd year, which means there are only 2 modules left to do. The first is in the first week of October and the assignment is due a month later, and the second is in December with the assignment due a couple of days before my birthday.
I do also have to write an 8000 word literature review before I have my first year review, which is scheduled for June, but can be pushed back depending on the amount of time I have off after the baby is born. In all honestly, I'm not planning on having any official time off, because if I take a suspension period, then my financial support stops, and I don't get any maternity pay as part of my studentship. If i'm 'working from home' then the money carries on, and as long as I'm organised, I can get a good chunk of the review written before the baby comes so I won't have a huge amount left to do before the first year review.
By the time I start proper serious data collection in my second year, the baby will be 7-8 months old and can go to nursery - I'm already on the waiting list for the university nursery, and the cost is subsidised because I'm a student so thats all perfect. Between the birth and nursery, either He will have to take his days off on the days I do go into uni. or mum can have the baby for a few hours. Its only really the first few months when I need to be there for breastfeeding, that the option for me to go to uni all day is pretty limited. Depending on where my office is based and how many people I share it with, I could even take the baby in with me for a few hours.
So thats the plan - obviously I'm aware that I may NEED to take some time out after the baby is born, and we'll just have to hope that financially we can cope by then - and this is all assuming that the later stages of my pregnancy are uncomplicated. I do always have the option to defer if things are getting too tough for me. The PhD can wait if needs be, spending time with my child can't.