A new report from the Guttmacher Institute, the nonprofit sexual health research organisation, shows that only two per cent of Catholic women, even those who regularly attend church, rely on natural family planning.

The latest data shows practices of Catholic women are in line with women of other religious affiliations and adult American women in general.

"In real-life America, contraceptive use and strong religious beliefs are highly compatible," said the report's lead author Rachel Jones.

She said most sexually active women who do not want to become pregnant practice contraception, and most use highly effective methods like sterilisation, the pill, or the intrauterine device (IUD).

"This is true for Evangelicals and Mainline Protestants, and it is true for Catholics, despite the Catholic hierarchy's strenuous opposition to contraception," Jones said.

Nearly 70 per cent of Catholic women use sterilisation, the birth control pill or an IUD, according to the Guttmacher Institute research.

The numbers are slightly higher among women who identify as Evangelicals or Mainline Protestants, research showed.

The latest data is from the 2006-2008 National Survey of Family Growth (NSFG).

The findings nearly match previous NSFG data from 2002, which showed that 97 per cent of Catholic women were using birth control, and are consistent with a trend tracked over the last decade by Catholics for Choice.

- Reuters