Third year of med school I worked 80-100hours per week. Because of the specialty I chose, third year was worse than intern year. I also breastfed as a third year -- pumping while at the hospital, and paid the price in supervisors being upset with me taking the time to do so (resulting in negative evaluations and grades). The culture of medicine is very macho and hierarchical. And dont forget about call -- thats where you work 24-28 hours straight. Most of us in residency do that every few nights. During training, medicine is one of the least family friendly careers out there. Honestly, with what you are saying, and all your concerns about hours worked, it does not sound like the career for you. It is the least family friendly thing I can imagine for wanting to have 4 kids and exclusively breast feed them all, work 25 hrs a week, etc. Medicine requires deep sacrifices that are hard to even explain.