The Holy See 'suspended' its objections to part of the text which referred to abortions being legal in some countries, in order to allow the 180 nations gathered in Cairo to reach a long-awaited consensus on an acceptable form of words.
The Vatican also withdrew its objection to the phrase 'family planning' in another part of the 133-page text, which has taken four meetings over an 18-month period to negotiate.
But on Monday, the day before the conference ends, delegates expect the Vatican to enter a written reservation, disassociating itself from parts of the agreement that it sees as condoning abortion.
It may be joined by a few other Catholic countries, including Malta and some countries in Latin America. Even so, most delegates believe that this will not lessen the impact of an agreement.
'This is a major contribution to the progress of the conference,' said Dr Joachim Navarro-Valls, spokesman of the Vatican's delegation. As the Holy See's representatives in Cairo came under increasing pressure, there were frequent consultations with Rome.
Pressure mounted as delegates expressed anger at seeing press coverage of a conference on population growth and women's rights to education, health care and family planning services increasingly dominated by abortion.
The most disputed piece of text will now read that the decision on whether abortions should be legal or illegal should be left to national governments. Abortion should not be used as a method of family planning. But women who undertake illegal, unsafe abortions have the right to counselling and medical care.
The Cairo agreement is intended to be a 20-year programme for all nations. If the agreement is carried out, it will help to stabilise the earth's fast-growing population by the mid-21st century. It now stands at 5.7 billion and is growing by 90 million each year. The key to achieving this is to improve medical care for mothers and babies, and to better the education of women. The Islamic fundamentalist threat to agreement petered out, leaving the Vatican isolated.