Helena Morrissey, chief executive of Newton Investment Management, said there is a tendency for women to have children later in life after establishing a career.
But the mother-of-nine argues that maternity shouldn’t impact on climbing the career ladder.
“My advice would be not to overthink it,” she told Evening Standard City Editor Chris Blackhurst on the Headline Interview.
“I believe having a few months or a year out in what might be a 40 year career is neither here nor there.”
The 48-year-old added that shared parental leave will improve prospects for mothers-to-be and should change attitudes within the work place.
Helena has been campaigning for better gender equality in the workplace for the last four years after founding the 30% Club.
The organisation’s goal is to have 30 per cent of company directors within the FTSE being women.
She said since starting out, there are now no male only company boards within the FTSE 100 and only 25 left within the FTSE 250.
Despite campaigning for 30 per cent, Helena said she doesn’t agree with quotas that are being proposed in the EU and doesn’t believe the move will bring meaningful results.
The organisation is also broadening its remit to look at gender diversity at all levels – from school to the workplace.
When Helena first started in the industry she said she felt passed up for a promotion after having her first child at 25.
She took the decision to take a junior role at Newton the same year. Since then she has risen up the ranks to become CEO.
She grew up in Cheshire with her parents, who both worked within education, and sister, who is a teacher.
She said she first learnt resilience as the only girl in an all-male maths class at A level.