OSLO - Women who have given birth to multiple children face a significantly reduced risk of developing certain types of cancers, according to a new large-scale Norwegian study, reported Xinhua.
The research, conducted by the Arctic University of Norway (UiT), found that the risk of breast, ovarian and uterine cancer decreases by approximately 10 per cent with each childbirth.
Women who have had six children face nearly half the risk compared to women who have not given birth, the Norwegian broadcaster NRK reported on Wednesday.
The study, led by Eiliv Lund, professor emeritus at UiT, analysed historical data from Norway's 1960 census and cancer registry records of more than 385,000 women born between 1870 and 1915.
Researchers looked far back in time to collect sufficient data on women with many children, as high fertility rates are rare in Norway today.
"Our analysis shows a consistent decrease in cancer risk with each childbirth, and the effect extends up to 15 children, something no previous studies have documented," Lund told NRK.
The study attributes this protective effect to hormonal and immunological changes that occur during pregnancy. Researchers observed nearly identical risk-reduction patterns across the three cancer types.
According to Lund, pregnancy requires the mother's immune system to adjust significantly, as the fetus is genetically distinct. This immune modulation is believed to play a role in reducing cancer risk later in life.
Giske Ursin, director of the Cancer Registry of Norway, noted that while the link between childbirth and reduced cancer risk has been known for years, this study is unique in its inclusion of women with up to 15 children.
"The findings add valuable insight into cancer prevention, even though women today have fewer children on average," she said.
The study was funded in part by the Norwegian Cancer Society, which highlighted the importance of further research into women's health. "
This is very exciting research that helps us improve prevention and treatment strategies," said Brage Larsen Sollund, regional director of the Norwegian Cancer Society in Northern Norway. - BERNAMA-XINHUA