The consequences for some unmarried women were devastating.
Between 1949 and the mid-1970s, an estimated 200,000 women were sent away to mother and baby homes run by churches and the state where babies were put up for adoption or died through poor care.
An ITV News' investigation has found accounts of cruelty and abuse inside several institutions.
St Monica’s maternity home in Kendal, which was run by the Church of England’s Diocese of Carlisle until its closure in 1970, has a dark history.
Burial records obtained by an ITV News Freedom of Information Request showed 45 babies who were born and died at the home are buried in a mass unmarked grave.
We also heard allegations from three different sources - including a family member - that mothers were denied modern medical care and babies with disabilities were left to die in agony.
“These women were treated as second-class citizens and their babies second-class babies, and in some cases worse,” Tim Farron, the MP for Westmorland and Lonsdale, told ITV News.
“It would appear that the babies who died here in Kendal were deemed to be less desirable for adoption. Babies, probably with disabilities or other medical conditions, were not afforded the most up-to-date maternity care that other babies may have been. It just smacks of a society where some people are seen as being less important than others,” he said.
Cumbria Police has confirmed it is investigating allegations of historic abuse and said it "would welcome any new information which would assist officers…following concerns raised in relation to these premises".
There is now a local campaign for a commemorative service and permanent memorial to the babies who died.
The Diocese of Carlisle, which ran the home from 1918 to 1970, said: “It is abhorrent to think that any child should be denied proper medical care and we would urge anyone with such information to contact Cumbria Constabulary.
"Having been made aware of the first allegations…we alerted police at the earliest opportunity,” a spokesperson said.
The suffering endured at St Monica’s was not a one-off.
Since our first report aired in July, more birth mothers have come forward to share their experiences of cruelty and abuse at other homes across England and Wales.
It was the mid-1960s when Ann Keen was sent away to a home for unmarried mothers in South Wales run by the Swansea and Brecon Diocesan Moral Welfare Association.
Pregnant and unmarried at 17, she recalled being treated like a "criminal" and told she was a "bad person".
She has never forgotten the "unnecessary cruelty" of the midwives and doctors who made her give birth without pain relief.
“I was extremely frightened, it was an atmosphere of punishment, you couldn’t have anything for the pain because ‘you’ve been a bad girl.’"
"They said things like 'you will remember the pain and then you won’t do it again’.”
Ms Keen was forced to give up her baby son for adoption after just eight days together and was even cheated out of saying goodbye.
"The midwife said 'oh he’s gone, he’s in that building and his new mummy is coming to collect him, and you will never see him again’, and I was just numb.
"We went to the bathroom and she got my breast and expressed the milk out of it and said ‘you won’t be needing this anymore’, it was just so cruel”, she told ITV News.
Ms Keen went on to become a Labour MP and junior health minister, but the trauma of that experience has never left her.
A Church in Wales spokesperson told ITV News that it had “apologised unreservedly for the harsh and unsympathetic treatment that Ann Keen says she received during her time in the mother and baby home…which closed in 1979.”
“We cannot undo the pain of the past but we are doing our best to make life better for families today.”
“On a Sunday we were paraded at church as the fallen women. Because we didn’t have a gold band on our hand, we weren’t fit to be mothers,” said Susan Burrough whose son was taken from her in 1964 after being sent to a home for unmarried mothers run by the Methodist Church in London.
Ms Burrough, who was 16 at the time, said she was repeatedly told that adoption was her "only choice".
The pain of that day, 60 years ago, has never left her.
“We were all made to be aware of the crime we had committed, in fact I believe we would have been treated with more respect had we have committed a murder.”
She went on to marry the baby’s father - but disowned by his own family he struggled to cope with the trauma of what had happened. He later took his own life.
In the years that followed, Susan tried to find her lost son.
“In 2009 I tried to make contact with my son - sadly he did not want contact with me.”
“When I got rejected it was like losing him all over again. I just wanted him to know how much I loved him. I did not give him up. I still have this huge hole in my heart and desire to find out who he is, I just want to know the man he has become,” she told ITV News.
A spokesperson for the Methodist Church said it is "so sorry for the impact that this has had".
“The care provided to many young women at the time is not what we would expect today as attitudes in society have changed and the church strives to be more inclusive.”
It added, the church is "determined to address historical hurt and injustices".
The Welsh and Scottish governments have formally apologised for their part in this scandal, but so far the UK government has refused to do the same, instead arguing that "the state did not actively support these practices".
The campaign group Movement for an Adoption Apology has called on the Labour government to "do the right thing and issue a formal apology to all affected" and to "ensure that everyone who has been traumatised receives the help they need" whether that be therapy, counselling or improved post-adoption support.
A Department for Education spokesperson said: “We have the deepest sympathy with all of those who are affected by historic forced adoption.
"The practice was abhorrent and should never have taken place. We will look to learn from the approach of the devolved nations and will explore what more can be done to support those impacted.”
The Diocese of Carlisle said in a statement: “Our thoughts and prayers remain with all those who have come forward with accounts of historical emotional abuse”.
It added it is committed to supporting those who have contacted the Diocese requesting access to documents in connection with the home.