Professor Roger Short, from the University of Melbourne, and Dr Kara Britt, from Monash University, argue in a comment piece in The Lancet, that since the contraceptive pill reduces overall mortality and mortality specifically linked to ovarian and uterine cancer, nuns should be given the pill for health, rather than contraceptive, reasons.
Nulliparous women – or women who do not have children - have more ovulatory menstrual cycles than women who have children, due to the absence of pregnancy and lactation. This increased number of cycles increases cancer risk. Other factors increasing the overall number of cycles, regardless of having children or not, also increase cancer risk, such as going through puberty earlier or menopause later. Women who have children further decrease their risk of these cancers if they have their first child at a young age, bear more children, and breastfeed.
The authors say studies have shown that overall mortality in women using the contraceptive pill is 12% lower than in those who have never used it. The risk of developing ovarian and endometrial cancers falls by 50-60% in pill users compared with women who have never used it, and protection persists for 20 years, showing a clear long-term benefit.
"Of course, as with any medication, the pill is not risk-free. For example, the combined oestrogen/progestogen pill can increase the risk of blood clots, and as such the woman's medical history should always be considered," they argue.
However they acknowledge that the Catholic church condemns all forms of contraception, as outlined by Pope Paul VI in Humanae Vitae in 1968.
"Humanae Vitae never mentions nuns, so they should be free to use the contraceptive pill to protect against the hazards of nulliparity since the document states that 'the Church in no way regards as unlawful therapeutic means considered necessary to cure organic diseases, even though they also have a contraceptive effect'.
"If the Catholic church could make the contraceptive pill freely available to all its nuns, it would reduce the risk of those accursed pests, cancer of the ovary and uterus, and give nuns' plight the recognition it deserves."