Women who have three children have a 50% lower risk of uterine cancer

According to research from the University of Queensland, having more children can reduce a woman's risk
of endometrial cancer.

According to research from the University of Queensland, having more children may reduce a woman's risk
of endometrial cancer.
Dr Gunn-Helen Moen and Dr Shannon D'Urso from the University of Queensland's Institute of Molecular Biosciences used genetic analysis to investigate risk factors for endometrial cancer and found that having three children reduced a woman's risk of endometrial cancer by 50%
compared to not having children.

Dr Moen said: "We found that the longer a woman is pregnant or taking birth control pills – the less estrogen the body is exposed to – the lower
the risk of endometrial cancer.
While previous studies have shown that multiple pregnancies and the use of oral contraceptives can reduce the risk of endometrial cancer, this is the first time genetics has been used to study multiple risk factors
at the same time.
”

Endometrial cancer, a type of cancer that affects the endometrium, is the fifth most common cancer among Australian women, with a prevalence of around 1 in 52
.
In their study, researchers at the University of Queensland used genetic analysis to examine the year a woman ovulated, which was calculated by subtracting the time it took to become pregnant or take birth control pills from menstrual time
.

"It is thought that high levels of estrogen are a risk factor for endometrial cancer, and progesterone does not combat
it.
Both pregnancy and birth control pills provide progestogens to fight estrogen, which may be why we see protective effects
against this cancer.
Simply put, the shorter the exposure to estrogen in a lifetime, the lower
the risk of endometrial cancer.
”

The researchers found evidence that reducing the number of years of ovulation can reduce the risk of endometrial cancer, but the strongest link points to fertility
.
Dr.
Moen says there may be several explanations
for why pregnancy reduces the risk of endometrial cancer.

"This could be an increase in protective progesterone later in pregnancy, or it could be because the body may remove precancerous endometrial cells from the uterus during delivery," Dr.
Moen said
.

In this study, the researchers isolated a number of known risk factors for endometrial cancer, such as an increase in body mass index (BMI) and the age of first menstruation and menopause, with a particular focus on the number of live births and the number of years of ovulation
.

"When obese, high levels of estrogen are produced in adipose tissue, which is a risk factor for endometrial cancer," says Dr.

Moen.

Endometrial cancer cases are increasing worldwide, and Dr Moen says this could be due to rising BMI levels, which account for about 40 percent
of endometrial cancer cases in developed countries.
"But we wanted to find out more about the effects of live birth directly, regardless of other known risk factors
.
" We used the data to study hundreds of genetic variants, six of which were associated with
the number of live births.
”

"This study is the first time we have been able to establish a causal relationship between the number of births and a reduced risk of endometrial cancer," Dr.
Moen said
.

However, researchers can't determine whether the same applies to multi-year ovulation and oral contraceptives
.

"Analyzing larger data sets can help us more clearly understand whether the hormonal or mechanical effects of pregnancy bring greater protection, as well as further dig into the effects of
oral contraceptives.
"

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