When Tracey Cosway’s children became teenagers, she looked forward to re-establishing her accounting career: bumping up from two days a week to five. “I thought the girls had grown up and this was [my] time,” she says. When her 23-year-old daughter gave birth 19 months ago, Ms Cosway reduced her days again to help out with her grandson.

So now Ms Cosway finds herself doing the work-toddler juggle again at a time when she had expected her career and finances to surge.

“There’s more pressure on the deadlines we need to hit. I didn’t expect to be doing this now.” She is surprised too by the guilt she feels about work, anxious that she is short-changing her employer.

On the other end of the see-saw of emotions, she is grateful for the time with her grandson and proud of their special bond (as well as being happy to return him to his mum). Without her help, she says, her daughter would not be able to pursue her studies and career at a bank, and pay for a couple of days at nursery.

“Childcare is so expensive. [My daughter’s] trying to build a career for herself. We’re all trying to juggle everything.” She can see it getting harder when her grandson starts school.

Her guilt about needing work flexibility has been reduced to some degree, she says, because her boss is sympathetic. As well she might be. After all, Ms Cosway's employer Claire Wood, co-founder of Truffle Shuffle, an online clothing retailer, depends on her own parents to look after her son two days a week and pick him up from nursery regularly.

“When it’s your own business you don’t have set hours. I’ve no idea what we would have done if it hadn’t been for my parents.”

The longevity revolution and financial pressures on pensions means that those in their 50s, 60s and even 80s might find themselves not only working longer but also cajoling toddlers – this time their grandchildren – into buggies while also keeping one eye on work emails.

The trend is driven by the rise in families in which both parents work as well as by increasingly expensive childcare.

According to research in 2014 by Ipsos Mori, 14 per cent of grandparents in the UK say they have reduced working hours, given up a job or taken time off in annual or sick leave to care for a grandchild.

Burnt-out grandparents had become so common in Spain that, in 2010, unions urged them to down tools and go on a childcare strike. In Germany, parents can transfer parental leave to a grandparent in some cases, and working grandparents are entitled to up to 10 days paid leave to look after a grandchild in an emergency.

Recently, the UK government announced a plan to change the rules on parental leave, so that parents would be able to transfer some of the paid time off work to a grandparent. It has recently extended credits in the state pension to those who regularly care for their grandchildren, in recognition of the fact that it can have a big impact on retirement savings.

Santander, the bank, in anticipation of these planned changes, is offering leave for grandparents in the first year of a grandchild’s life. In Australia, Westpac bank offers up to 52 weeks unpaid leave to employees who are their grandchild’s primary carer until their second birthday. Heritage, another Australian bank, provides leave for employees to look after grandchildren as well as to look after elderly relatives.

In countries with ageing populations, grandparents in the workforce might be pulled in both directions – caring for babies and ageing relatives.

One such person is Deborah Ejenas, communications manager at Bright Horizons, the US childcare provider. The grandmother has a variety of familial pressures on her time and has used emergency back-up care services for her mother, who lives two hours away.

“Balancing childcare with my work commitments and distance caring for my 84-year-old mother, who is fortunately very independent, can be a challenge from time to time. My daughter and mother would struggle without the care I provide.”

Amy Goyer, family and ageing expert at AARP (formerly the American Association of Retired Persons), says employers are unsympathetic. "Some just don't acknowledge a grandparent's role in childcare. They may not understand why grandparents may need time off work for a grandchild's doctor appointment, school meetings and events, sickness."

Childcare obligations affect working grandparents differently according to their income. Myra Hamilton, research fellow in the Social Policy Research Centre at the University of New South Wales, Australia, has investigated the effects of regular childcare provision on grandparents' work and retirement decisions.

Grandparents on a lower income, according to her research, were less likely to say they were caring for grandchildren in order to spend time with them and more likely to cite barriers in the formal childcare system. Higher income grandparents were less likely to say that their income was affected by their caring responsibilities.

There are gender differences between working grandparents. Dr Hamilton observes that most grandparents providing regular childcare are grandmothers. “When you ask why they are required to provide care, most say it is so that their daughters and daughters-in-law can participate in work.”

In effect, grandmothers are altering and reducing their work to facilitate the workforce participation of their daughters and daughters-in-law.

Dr Hamilton also found that patterns of work and care in parents are reproduced in grandparents. “Where grandfathers are involved in care for grandchildren – and many are – they are more likely to be involved in tasks like playing with or transporting grandchildren, whereas grandmothers tend to take on the repetitive tasks such as bathing and changing.”

Those women who have already taken time out of their careers to look after their own children might find their hopes for a professional revival take a hit.

Joan Williams, founding director of the Centre for WorkLife Law, a non-profit research and advocacy group based at the University of California, says the arc of professional development has been different for men and women. "For men it's very straight up, whereas for women in their 50s it might be an opportunity to jump back in."

She adds a further concern: "Do childcare responsibilities create a perception that no working woman is ever dependable and a societal expectation that women must look after kids?" – (Copyright The Financial Times Limited 2016)