freetext responses by participants:

general comments
1st child's effect on career
2nd child's effect on career

statistics about the survey:

who took the survey
age and kids
time off and childcare
effect of child on work
gender ratios

other resources:

MamaPhD blog
Do babies matter?
Mind the gap
University of Michigan: Advance program

 

Effect of having children on time spent working

 

How were women's work hours affected relative to their hours prior to maternity leave?

A fair fraction of women worked fewer hours once they returned to work, and the proportions were similar, whether it was the 1st or 2nd child (with a slightly smaller impact of the 2nd child).

Women on the tenure track were more likely to work fewer hours than before, likely a reduction from a very heavy workload to begin with.