Businesswoman and office workers
Many women are still forced to make the choice between career and familyFlickr

In a previous life, I left a job in a bank when I was five months pregnant. I'd heard something I wasn't meant to; my bosses discussing how they were going to cut my clients out of a lucrative deal because I'd be off soon and the chances were I wouldn't be coming back.

I was pole-axed. I'd worked like a Trojan for years, performed well and been promoted fast. But when it came down to it, this was no place for me and I left, which of course proved my bosses right after all.

It turns out I was just one statistic in a massive trend: across the UK workforce, mothers' careers take a nosedive post-children. As a Mumsnet user glumly notes: "Having the audacity to become a mother seems to be the death-knell for many women's careers even now."

Women's earnings are within striking distance of men's until they hit their thirties; by the time workers are in their forties, the earnings gap between men and women is heading towards 25%. Few dispute that motherhood explains most of the widening gap in pay and seniority.

Negative effects

Over the past few weeks, we've been asking Mumsnet users about their experience of the delicate intersection between family and work and the results are frankly a bit depressing. Over nine in 10 (91%) recognise the "motherhood penalty" phenomenon, while 65% said having children had had a negative effect on their career; yet 73% said becoming a parent had no effect on their spouse's career at all.

It's crucial that we try to tackle this unfairness. Nobody (not employers and certainly not the economy) benefits when such an enormous group of people aren't fully deploying all they have to offer at work.

When asked about what recruiters should focus on, Mumsnet users cited things like flexible or part-time working, and a need for empathetic line managers. Employers might find it helpful to think of think of this as an attitude tweak rather than a fundamental rethink of business models: it's really just about treating your employees like grown-ups.

Modern tech gives most of us the freedom to work from home, from outside the nursery gates and from the sofa after dinner. So when a member of staff asks for time out to attend a sports day, why not trust them to make up the time? Unless your recruitment processes are really outstandingly bad, your staff are probably not con-merchants whose only wish is to make a fool out of you.

Time to step up to the plate

Things like consistent, targeted support and training updates for those returning from parental leave might require a bit of adjustment, but no functioning business (apart, perhaps, from the smallest and newest) can seriously argue that they're a major impediment.

And while we've seen the UK government make big and welcome promises of further free childcare for pre-schoolers, it's probably time that more organisations – especially those with large workforces – stepped up to the plate when it comes to contributing to childcare solutions.

Students taking exam

'None of us wants to hear our child, whatever we may think, is a vile little blighter or a hopeless case. The problem is this often leaves us floundering - unable to read between the lines and unsure what exactly the teacher is trying to say.'

Read Justine's guide to school reports here (pic: Reuters)

Our Family Friendly programme showcases innovative practices in these areas from many UK companies; the excuse that it's all just too difficult and expensive doesn't really wash any more.

I'm rather glad I heard that conversation between my bosses many years ago, because it gave me the idea to start Mumsnet a couple of years later. After all, if I was in charge, I could guarantee a family friendly workplace. Too often in finance I'd seen the few women who did get ahead pretending their children didn't exist.

I wanted Mumsnet to recognise one essential fact: if you're a parent, your children come first, and work second – and now, following the launch last weekend of our Mumsnet Jobs site, we're hoping to encourage other businesses to be out and proud about their family friendly credentials.

The race is on to provide excellent working environments for people whose lives don't stop at the office door, and the reward for those who succeed will be highly committed, motivated staff who aren't constantly scanning the horizon for something new.

Justine Roberts is founder and chief executive of Mumsnet and Gransnet. She has also sat on the Expert Steering Group on Family Support Services, the Consultative Council of the British Board of Film Classification and the Commission on Civil Society and Democratic Engagement.

You can find her own Twitter @Justine_Roberts, or visit the Mumsnet page @MumsnetTowers. Alternatively, for all information about Mumsnet please visit the website here.