there are other posts on this, in my opinion having spousal support and really good communication is key, in my pre-med courses often I'd get so into studying that an interruption by my kids was likely to cause annoyance at losing my study-train-of-thought rather than parental feelings. That's when it helps to have a spouse who was comfortable calling me on this. There needs to be balance rather than solely a focus on academic pursuits.
I've read good things about parents setting aside specific times, both for family activities and for being a spouse (rather than a parent) as key to making it through. And that M1 & M2 are far more conducive to school-life balance than M3 and M4 due to rotations and overnight hospital stays.
I do know that with my younger child being 5, parenting is much easier than it was when the kids were young, they're fine if need be on their own for hours at a time with very limited guidance; as newborns they needed constant attention. But I expect there to be a price; I'll be studying and away from the family for many more hours than if I followed a different path. But I"ll also be able to pay for the kids' college, realistically, anywhere which is important to me, and set aside enough to retire comfortably.