Premature babies should not always receive treatment, experts say.
Many premature babies have significant disabilities
They argue it is not always in their best interests and can cause unnecessary suffering.
What is being proposed?
The Nuffield Council on Bioethics has recommended babies born at or before 22 weeks should not be resuscitated or given intensive care.
Between 22 weeks and 23 weeks the assumption should be no care unless parents request it.
From 23 to 24 weeks parents should have final say.
And between 24 and 25 weeks the assumption should be that intensive care should be given unless parents and doctors agree there is no hope. Beyond that intensive care should be given as standard.
Why is this being proposed?
Before 1980 hardly any babies survived if they were born before 28 weeks. But advances in medical technology mean that over recent years those being born earlier are surviving.
In 1995, the percentage of babies born alive between 22 and 23 weeks who survive to leave hospital was 1%, at 23 to 24 weeks it was 11%, at 24 to 25 weeks it was a quarter and at 25 to 26 weeks it was 44%. Survival before 22 weeks was very rare.
Since the mid 1990s, survival rates have improved, although these statistics are still the most accurate available.
However, despite the improving survival rates over recent decades many of the premature babies, especially those born before 24 weeks, which do survive are left with disabilities.
What medical advances have taken place?
Doctors say much progress has been made after they have become better at ventilation and controlling babies' temperatures.
Women who are likely to give birth early are also given steroids to help develop the babies' lungs - the last things to properly form before birth.
But critics say medical advancements can also lead to unnecessary suffering. Babies born prematurely will have a series of invasive and painful procedures carried out including blood samples and pipes being fed down the throat.
If the baby has a very slim chance of surviving, some question whether this is the right thing to do.
What is current practice?
At the moment, the law allows doctors and parents to withdraw treatment if they feel it is in the best interests of the baby.
The problem is that there have been several recent high profile cases where parents and doctors have disagreed over the appropriate treatment and this has led them to court.
The Nuffield Council is seeking to avoid this in the future by spelling out a framework that should be followed.
Do doctors support the new guidelines?
The guidelines have received a widespread welcome. However, some doctors have expressed disquiet at the idea that treatment decisions can be based solely on the gestational age of the infant.
Professor John Wyatt, an expert in noeonatal paediatrics at University College London, said: "In practice assessing the maturity of babies can be unreliable and can vary by up to two weeks.
"Although I welcome the guidelines, I believe that doctors must continue to individualise care in each unique situatiuon - in other words cut off times don't necessarily fit neatly with clinical practice."
What else does the report cover?
The Nuffield Council has also dealt with the support given to families at the time the decision is taken and in the future, both of which it says are inconsistent across the country.
The think-tank also said doctors should be getting a second medical opinion or involving a medical ethics expert to reassure parents the decision is in the best interest. This practice would help to avoid court cases, the report said.
The report also rules out any suggestion that doctors should intentionally end the life of a critically ill baby.