Pope Benedict XVI on Friday reaffirmed the Catholic Church's opposition to contraception and lamented that many Catholics ''have difficulty'' in understanding the Church's stance on the issue.
In a message to a Rome conference on the 40th anniversary of a landmark papal encyclical on contraception by Pope Paul VI, Benedict said the use of contraception ''means negating the intimate truth of matrimonial love, with which the divine gift (of new life) is communicated''.
Because there are ''so many Catholics in the world today'' who fail to understand the Church's message, the Church must redouble its efforts to help couples comprehend ''the beauty of conjugal love in its natural state'', according to the pontiff.
But the pope said the rhythm method of contraception was acceptable for couples who need to space children or stop having them altogether because of ''dire circumstances'' in their lives.
''In these cases knowledge of the woman's natural rhythms of fertility becomes important for the life of the couple,'' he said.
In July around 50 Catholic groups based mainly in the United States and Europe published an open letter to Pope Benedict in the Corriere della Sera newspaper claiming the Church's position on contraception had had a ''catastrophic impact on the poor and powerless around the world'' and asking him to reverse it.
Vatican Press Office spokesman Father Federico Lombardi at the time dismissed the letter, saying that many of the groups that had signed it were ''very insignificant''.
