Girls who start their periods before the age of 12 may have an increased risk of developing cardiovascular disease later in life, the results of a new study indicate.

Cardiovascular disease includes all diseases of the heart and circulatory system, but it most commonly refers to heart disease, stroke and other blood vessel diseases.

Previous research has suggested that certain reproductive risk factors are linked with cardiovascular problems later in life, however the findings have been mixed. UK researchers decided to look into this further.

They used data from the UK Biobank, a large population-based study involving over 500,000 men and women who were recruited between 2006 and 2010.

Overall, the health of over 267,000 women and more than 215,000 men was tracked up to March 2016, or until they had their first heart attack or stroke. None of the participants had cardiovascular disease when the study began.

The researchers found that the average age for females starting their periods was 13 years.

They monitored a specific seven-year period and during that time, they recorded over 9,000 cases of cardiovascular disease, 34% of which were in women.

Following an analysis of the data, and after taking account of factors that may have affected the results, the study found that who had started their periods early - before the age of 12 - had a 10% increased risk of developing cardiovascular disease compared to those who started at the age of 13 or older.

The study also found that those who went through the menopause early - before the age of 47 - had a 33% increased risk of cardiovascular disease.

Previous miscarriages were also linked with an increased risk of heart disease, with each miscarriage increasing the risk by 6%. Furthermore, those who experienced a stillbirth had a 22% increased risk of developing cardiovascular disease.

Women who had undergone a hysterectomy also had a 12% increased risk of cardiovascular disease and a 20% increased risk of heart disease. Those who had their ovaries removed before a hysterectomy were twice as likely to develop cardiovascular disease compared to those who had not had these procedures.

The researchers acknowledged that this is an observational study, so no firm conclusions can be drawn. However, it was a large study and they were able to account for a range of factors that may have influenced the results.

"More frequent cardiovascular screening would seem to be sensible among women who are early in their reproductive cycle, or who have a history of adverse reproductive events or a hysterectomy, as this might help to delay or prevent their onset of cardiovascular disease," the team from the University of Oxford advised.

Details of these findings are published in the journal, Heart.