Likewise, Margaret E. Law, senior lecturer on physics, chose to delay having children. But that choice led to her sacrificing a family altogether.

"It wasn't an absolute decision on my part. We never planned not to have children," Law says. "We just never got around to having children."

"I felt I needed to establish a career first," she says.

But Law's experience is unusual. Most women have managed to find points during their careers when having chidden was at least feasible, it not easy. Some like Skocpol have chosen to wait until they have been tenured.

Professor of Chemistry Cynthia M. Friend had her daughter Ayse, now 13, after receiving her Ph.D. and about two months before she began teaching at Harvard. Her son Kurt, 11, was born two years later.

"It seemed like a good break point in my career, and I had a tremendous amount of energy," Friend says, "I have many more demands on my time as a senior faculty member because [1] have more responsibility to the institution and to the outside community."

"I would find it much harder, with the combination of energy level and other commitments, to start a family now," she says. "I also know many women who have deferred having a family and were subsequently unable to do so for various reasons."

But Skocpol says having a young son has reenergize her life.

"There are advantages to having a child later. We are secure in our careers. We had enough money to afford excellent day care and an excellent school," Skocpol says. "Having a child rejuvenates you. That's very, very pleasant in one's 40s."

But however pleasant motherhood may be, female faculty members acknowledge that having an academic career has meant limiting the size of their families.

"I sometimes feel it would have been nice to have two children instead of one," says Skocpol. "That would have been possible if we'd started earlier."

Mandryk and her husband had considered having a third child.

"It was a theoretical possibility before I came here," she says, "But unless I simply quit sleeping altogether there is no more time I can squeeze out of my life."

"I do think I might have managed [to have a third child] at a less intense institution in a less expensive area," Mandryk says.

Assistant Professor of Economics Donald R. Davis says the challenge of balancing work and family is not faced solely by women.