London, Oct 13 (IANS): The age at which a young woman experiences her first menstruation is associated with the age at which her son experiences puberty, according to a latest research.

While it has been known for some time that mothers' age at puberty is associated with their daughters', much less was known about the link with their sons' age at puberty.

The findings, published in the journal Human Reproduction, suggested that mothers who reported having their first menstrual bleed earlier than their peers had sons with signs of puberty starting earlier than their peers.

"The relationship between first menstrual bleeding in mothers and the first menstrual bleeding in their daughters has been reported in several studies," said Nis Brix, researcher at the Aarhus University in Denmark.

"The novelty of our study was to include other markers of pubertal development in daughters, such as different stages of breast and pubic hair development. The relationship in sons has only been sparsely investigated," Brix added.

For the study, the researchers examined 15,822 children and interviewed the mothers twice during pregnancy and asked them to fill in a questionnaire when their children were seven.

"The largest difference was when hair started growing in the armpits, which started, on average, approximately two-and-a-half months earlier; their voices broke nearly two months earlier, acne started to develop nearly two months earlier and their first ejaculation of semen was nearly one and a half months earlier," Brix said.

However, in girls, the largest difference was seen in breast development, which started up to six months earlier in those whose mothers had experienced earlier periods than their peers, or up to four months later in girls whose mothers had started puberty later than their peers.

Puberty at a younger age has also been linked to increased risk in later adult life of diseases such as breast and testicular cancer, diabetes and cardiovascular disease.