Mothers of premature babies are calling for their statutory maternity leave to be extended.
The 52 weeks of maternity leave kick in for the mothers of premature babies the day after a baby is born.
As a result, women can lose weeks of bonding at home if their child arrives early and goes on to spend weeks in hospital before being allowed to leave.
MPs will now debate whether to allow a leave extension, following a campaign by London mum-of-two Catriona Ogilvy.
Mrs Ogilvy began her fight to increase leave after her first son, Samuel, was born 10 weeks prematurely.
"I am so glad it is finally coming to Parliament," she said. "We will need to secure a full debate, hopefully before Christmas, but this is a good step."
Mrs Ogilvy's baby boy had to be resuscitated for six minutes after he was born in 2011 and it was six days before she was able to hold him.
"I went home the day I gave birth and I was still in a state of shock," she said. "Within hours my baby was whisked away and two hours after that I went to see him.
"Only when I got into bed that night did I feel empty. No baby in or out. I felt loss."
It was then eight weeks before the 35-year-old was able to bring him back home to Norbury, south London, and that was still two weeks before his due date.
Mrs Ogilvy had to go through it all again when her second son, Jack, was also born prematurely and needed to spend two weeks in hospital.
The former neonatal worker was surprised to discover the statutory maternity leave had kicked in straight away.
"It was a complete shock to the system," said Mrs Ogilvy. "Having worked there, I thought I knew all there was to know, but all those families were using their maternity leave sat in a hospital.
"It really kicks in when you get home and you can be a mum to your baby for the first time. Then all that time is taken away from you and you have to go back to work when they are so tiny. It is a bitter pill to swallow."
The couple are among thousands to go through the same experience.
Up to 40,000 babies are born prematurely in the UK every year and the average stay in hospital for each child is eight weeks.
Mrs Ogilvy was inspired to launch the Smallest Things campaign with an online petition supporting an extra week's leave for every week parents of premature children have to spend waiting in hospital for their child to be allowed home.
It now has more than 100,000 signatures.
What is statutory maternity leave?
Statutory maternity leave is a right for mothers to take time off after they have a baby and to receive payment from their employers.
- Leave is for up to 52 weeks
- Most women choose when to start their maternity leave, any time up to 11 weeks before their due date
- But if the baby is born early it begins the day after the birth
- It also kicks in automatically if you are off work for a pregnancy-related illness in the four weeks before your baby is due
- You receive 90% of your average weekly earnings (before tax) for the first six weeks
- You then receive £139.58 or 90% of your average weekly earnings (whichever is lower) for the next 33 weeks
- Parents are now able to split their leave if the mother wants to go back to work - shared parental leave
Her local MP, Labour's Steve Reed, has tabled an early motion for the longer pay period, which will be debated in Parliament on Wednesday.
"No parent should be left alone to deal with the emotional and financial stress of balancing employment and care for a baby born too soon or too sick," he said.
"This is a small change but one which will bring a serious improvement to the lives of thousands of families."
But the Department for Business said the system was already fair.
A spokesman said: "The UK's maternity system is one of the most generous in the world. The current system strikes the right balance between the needs of new mums, including those whose baby has been born prematurely, and employers."
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Karen Stirrat had her triplets Caleb, Poppy and Alicia, 13 weeks early.
She told BBC Breakfast of the nightmare she faced travelling between the hospital and home.
"Caleb came home at six weeks, but for the girls it was 12 weeks then 13 weeks," she said. "At that point that's even more stressful, having to go back and forth to hospital.
"Then you are left with all the hospital appointments, like now there are appointments every three weeks for injections over the winter. You can't really hold down a full-time job and everything else."
Caroline Davey, chief executive of baby charity Bliss, criticised the "one-size-fits-all system" and said the cost of having a premature baby in hospital can be up to £230 a week for travelling parents.
She said: "Premature babies often develop slower and so at the time the mother needs to go back to work the baby might not yet be ready for childcare.
"It would be fairer for everyone to get 12 months at home or 12 months from due date would make sense also."
But lawyers have warned that the extension of leave could hit businesses hard.
Aye Limbin Glassey, employment law partner at Shakespeare Martineau, said: "While this would be popular with parents, it would place considerable pressure on some employers - particularly smaller businesses that might struggle to keep jobs open for workers for a longer period of time and would undoubtedly feel the added financial strain.
"We recommend that employers treat the issue with sensitivity and, where possible, consider flexible working requests. There is a clear business reason to do so [and] they need to be aware that they could lose valuable members of staff."