Mothers in professional workplace settings are being forced to work long hours, regardless of preset negotiated hours, as well as schmooze at company events and in after hour social settings, which often clashes with their childcare responsibilities. Because of this working culture, which is predominantly still organized by men, many mothers are leaving their jobs or taking lower ranking titles in order to spend more time at home.

"Unless mothers mimic successful men, they do not look the part for success in organizations", said a research paper, written by Emma Cahusac, series producer of BBC Television's "The Culture Show" and Shireen Kanji, Senior Lecturer in Work and Organization at the University of Leicester School of Management.

The researchers interviewed 26 professional mothers based in London who had quit their jobs while pregnant, or following their return to work, but before their first child reached school age. Twenty-one of the women surveyed had quit their jobs voluntarily often because they had been sidelined after returning to the workplace.

Additionally, many of the women found it hard to combine both work and motherhood because of the strong idea of presenteeism, which is the notion that they should be at their desks until late, even if there is no work to be done. "I would be in work by eight, but I would have to leave by six and actually I could do the job perfectly well," said ex-banker, Susan.

The researchers found, however, that before the women had children themselves, they accepted and encouraged the masculine culture of the workplace.

The mothers also stated the need to hide the fact that they were parents. "The male partners never talk about their families," said Nadia, a lawyer. "They've been very adept at keeping that separation between work and home."  Mothers particularly had to hide the fact that they were taking time off to look after sick children.

The findings are presented in the journal Gender, Work and Organization. .

"Many women leave high-powered jobs because they are relegated to lesser roles and feel the need to suppress their identities as mothers," said Kanji. "This is not only unfair. As an economy, we cannot afford to waste such skilled and educated workers."