Professor Lisa Looney:

This is very complex. If we look at what happens at postdoctoral level, though, we see people enter into a career phase where there is contract-based employment. People do one postdoc, then another one and then another. If we look at the age profile of that cohort, that period begins to intersect with the time in many people's lives when they are beginning to start families, etc. What we see then is that many of those female STEM graduates move across into research support roles within universities, for example.