Chemist Carolyn Carr took a ten-year career break to look after her two children. She said many women in her position felt it was impossible to break back into science.
"One big problem is getting your confidence back in the face of all these bright young graduates," she said.
Dr Carr, who works for the neuroscience-based biotech company Synaptica, became pregnant while completing a PhD at Oxford University.
When she began to consider a return to work, she found her field had moved on at an alarming rate in the years she had been out of the laboratory.
"Experiments I never would have dreamt of attempting when I was studying were now being done routinely," she said.
In response to her applications for science jobs she received a stream of standard-issue rejection letters.
She said: "I wanted to write to companies and offer to come in on a graduate salary, but things don't work like that."
Just as she was growing desperate she won a two-year part-time fellowship from the Daphne Jackson Trust, an organisation that helps female scientists to return to work. This enabled her to return to Oxford to undertake spectroscopy research.
"They paid me on a first-year postdoctorate researcher's salary, part time, so it wasn't a big sum. But by then I was so grateful to have something it didn't matter," she said.
She added that the system had failed many female scientists in the past.
"I didn't want to miss out on my children growing up. A lot of women in science feel the same way, but don't dare to take a break as they think they will never get back in."