Sons born to women with polycystic ovary syndrome (PCOS), one of the most common causes of female infertility affecting millions of women of reproductive age, are three times more likely to develop obesity, a new study has found.

Researchers from Karolinska Institutet discovered the previously unknown risk of passing PCOS-related health problems across generations through the male side of a family in a study whose findings were published in Cell Reports Medicine.

PCOS is a condition that causes irregular menstrual cycles, missed periods and unpredictable ovulation in women due to hormonal imbalance. Women with PCOS have excessive amounts of androgens or the male sex hormones that are otherwise present in small amounts.

It is estimated that around 15% of women of reproductive age have PCOS.

In addition to causing infertility, PCOS has been linked to a series of health issues such as diabetes, obesity, heart disease, stroke and mental illness.

The exact cause of PCOS is not known, but those who are overweight and with a family history of diabetes, insulin resistance or PCOS are more likely to develop the condition.

The common symptoms of PCOS include irregular periods, abnormal hair growth, obesity, infertility, thinning of hair, acne and darkening of skin.

Earlier studies have found that daughters of women with PCOS are at a fivefold risk of developing the same condition. However, it was unclear how PCOS affected the health of sons until the research team found that they are more likely to have weight and hormone problems.

The research team behind the new study evaluated the data of 460,000 sons born in Sweden between July 2006 and December 2015. Among them, 9,000 were sons of women with PCOS. The researchers then identified the children who were obese.

"We discovered that sons of women with PCOS have a threefold risk of obesity and of having high levels of 'bad' cholesterol, which increases the risk of developing insulin resistance and type 2 diabetes later in life," Elisabet Stener-Victorin, who led the study, said in a news release.

The findings of the research were further confirmed through a mice study wherein female mice were fed either a standard diet or a diet rich in fat and sugar before and during pregnancy and exposed to high levels of male sex hormones.

The researchers then evaluated the male offspring of the female mice, who were fed a standard diet until adulthood. When the fat distribution and metabolism of the male mice were examined, they were found to have more fat tissue, larger fat cells and a disordered basal metabolism.

"Through these experiments, we can show that obesity and high levels of male hormones in the woman during pregnancy can cause long-term health problems in the male offspring. Their fat tissue function, metabolism and reproductive function deteriorate, which in turn affects future generations," Qiaolin Deng, one of the researchers involved in the study, said.

"These findings are important because they highlight the risk of passing health problems down through the male side of a family, highlight the risk of passing this kind of health problem, and they may help us in the future to find ways to identify, treat and prevent reproductive and metabolic diseases at an early stage," Stener-Victorin added.

mother and son
The sons of women with PCOS are three times more likely to develop obesity, a new study has found. pixabay