Doctors at the British Medical Association conference in Manchester have voted against reducing the upper limit for abortion.
Doctors will discuss at what stage of pregnancy abortion should stop
Representatives overwhelmingly rejected a motion calling for the upper limit to be cut from 24 to 20 weeks.
The current time limit has been questioned as medical progress has boosted the survival chances of premature babies.
However, many very premature babies who survive have severe disabilities.
This was the first time the BMA conference had debated abortion limits since 1989.
ABORTION RATES PER 1,000 WOMEN AGED 15 TO 44
1969 - 5.3
1979 - 12
1989 - 15.5
1999 - 16.2
2003 - 16.6
Representatives at the conference voted by 77% against the motion "that this meeting holds that the upper limit for legal abortion should be reduced in light of new evidence of foetal developments and advances in neonatal care".
Speakers said late abortions were distressing, but often necessary if a pregnancy was detected late or severe abnormalities were discovered in the baby.
Less than 1% of the 190,000 abortions a year in England and Wales are carried out after 22 weeks with 87% before 13 weeks.
The abortion rate has more than trebled since it was legalised in 1969.
John McQueen, who proposed the motion, said in the past babies born before 28 weeks would have died, but now they were surviving from as young as 23 weeks.
ABORTION TIME LIMITS
France: 12 weeks
Germany: 12 weeks
Italy: 13 weeks
Sweden: 18 weeks
US: limits after 26 weeks
Australia: No limit
He said it was important there should be a clear window between the viability of a foetus and the upper limit for abortion.
Dr Jan Wise called for delegates to reject any moves to lower the time limit.
He said only a small number of abortions were carried out after 20 weeks - often because of difficulties accessing services.
It would be "shameful" if the BMA supported lowering the limit, he said.
"There is a lot of anguish in deciding to have such a termination.
"This puts an extra burden on the vulnerable and weak who have decided to take this terrible last step."
Dr Vivienne Nathanson, the BMA's head of science and ethics, said the result of the vote was "compassion winning out".
She said: "Patients find it an extremely difficult decision to make and for many people late terminations are a result of things that are largely out of their control."
Campaigners remain divided over whether the upper limit for abortion should be altered.
Anne Weyman, chief executive of the Family Planning Association, welcomed the vote to maintain the current position.
She said: "Women faced with the decision to have a late abortion do not make this decision lightly and do so under extremely difficult circumstances.
"Abortion services in the UK are not seen as a priority and many women face problems even trying to obtain an early termination."
But Christa Malkin, of the charity Life, said: "This vote is a sad reflection on the medical profession and shows how out-of-step with public opinion they are.
"There is growing disquiet in society about the sheer number of abortions being performed and particular concern about late-term abortions.
"The vast majority of the public find the abortion of babies which could survive outside the womb extremely disturbing."
Julia Millington, of the ProLife Alliance, echoed that view.
She said: "Medical advances have increased our understanding of life in the womb and, as a consequence, there is a groundswell of support for a change in the law."