My supervisors encouraged me to take break time to pump milk in the office even when I was only there for 3 hours a day. I was considered full time working 30 or more hours a week so I maintained my health insurance, vacation and sick leave benefits.
This arrangement is still working for me and my company and my son is currently 15 months old. When he a little older I will go into the office 8 hours a day, but only work 4 days a week. If not for this flexible work environment I feel I may have quit my job and the company would have lost all the knowledge and 6 years of experience. In fact I was the most senior person in the department and had created much of the work-flow procedures and they struggled while I was gone.
For me personally my son has never had to be in day care as my husband works from home and is able to work and take care of the kid while I am needed in the office. My son also has been able to exclusively breast feed, a real benefit.