Having babies can halve a woman’s risk of developing this type of cancer

By Alice Clifford via SWNS

Having babies can halve a woman’s risk of developing endometrial cancer, a new study reveals.

Giving birth to three babies compared to none could decrease a woman’s risk by 50 percent.

Pregnancy, as well as taking the contraceptive pill, has this effect, as it lowers the level of the hormone estrogen in the body.

High levels of estrogen are a key risk factor for developing endometrial cancer.

While there are many types of contraceptive pills, one of the most commonly used produces progesterone and stops ovulation, reducing the level of estrogen.

Dr. Gunn-Helen Moen, from the University of Queensland’s Institute for Molecular Bioscience, and co-author of the study, said: “It is thought that high levels of estrogen, unopposed by progesterone, is a risk factor for developing endometrial cancer.

“Pregnancy and the contraceptive pill both provide progesterone to oppose estrogen, and this could be why we see a protective effect against this cancer.

“To put it simply, the shorter the exposure to estrogen over your lifetime, the smaller your risk of developing endometrial cancer.”

Endometrial cancer occurs in the lining of the uterus and is the fifth most diagnosed cancer in Australian women, affecting one in 52 women.

In the UK, it is the fourth most common cancer for women. It accounts for five percent of new cancer cases in females.

While the contraceptive pill helps lower the risk, the study showed that childbirth has greater protective power against endometrial cancer.

Dr. Moen explained: “It could be the increase in protective progesterone in the latter stages of pregnancy, or it could be because the body potentially removes pre-cancerous endometrial cells from the uterus during birth."

Other risk factors of endometrial cancer include obesity and the age at a person’s first menstruation and menopause, as the more someone ovulates the greater the risk. As a result, older women are more likely to suffer from this cancer.

Cases of endometrial cancer is on the increase worldwide, which Dr. Moen partially attributes to rising obesity across the globe.

Obesity is the reason for 40 percent of endometrial cancer cases in developed countries.

Dr. Moen said: “In obesity, high levels of estrogen are produced in fat tissue, which makes it a risk factor for endometrial cancer."

While these are key risk factors, the researchers used genetic analysis to specifically focus on the effect of the number of live births and years a person ovulated to see how pregnancy specifically lowers risk.

Dr. Moen said: “We wanted to find out more about the impacts of live births directly, irrespective of other known risk factors.

“We used data to study hundreds of genetic variants, six of which were associated with the number of live births.”

According to the NHS, symptoms of endometrial cancer include pain in the lower back or between the hip bones, bleeding or spotting from after menopause, unusually heavy periods and pain during sex.

The study was published in the journal BMC Medicine.