Women who got their first period at age 11 or earlier are at higher risk of developing diabetes during pregnancy, a recent Australian study suggests.
Being overweight is known to be a factor in early periods and also in what's known as gestational diabetes, but it did not fully explain the link between the two conditions, the researchers write in the American Journal of Epidemiology.
Diabetes develops in as many as 9 percent of pregnant women in the United States and can carry serious health risks, according to the Centers for Disease Control and Prevention.
Mothers with gestational diabetes are more likely to have high blood pressure and go into premature labor, said lead study author Danielle Schoenaker, a research officer at The University of Queensland.
"There are also consequences for the baby, which is more likely to grow faster and be larger at birth," Schoenaker told Reuters Health by email. "In the longer term, both mothers and their children are at higher risk of developing type 2 diabetes later in life."
To explore the link between women's age at first menstruation, known as menarche, and their risk of developing gestational diabetes, the study team analyzed data on nearly 5,000 women participating in the larger Australian Longitudinal Study on Women's Health between 2000 and 2012.
The women included in the analysis all reported a live birth during the study and had completed a questionnaire every three to four years, answering questions about when they had their first period and whether they were diagnosed or treated for diabetes during pregnancy. None had type 2 diabetes or a previous history of gestational diabetes at the start of the study.
The average age at which women got their first period was just under 13 years, researchers found.
Women who had their first period at or before age 11 were more likely to have been overweight in childhood, to engage in little physical activity as adults and to currently be overweight or obese.
Overall, 357 women, or about 7.5 percent of the participants, reported being diagnosed with gestational diabetes. These women were also more likely to be overweight or obese and to have a sedentary lifestyle at the beginning of the study.
Women who got their first period before age 11 were 51 percent more likely to develop gestational diabetes, compared with those who started menstruating at age 13.
This was true even after the researchers took into account things that might influence age at menarche or risk for gestational diabetes, including mothers' education level, physical activity, previous children, a hormonal condition known as polycystic ovary syndrome and body mass index (BMI), a measure of body fat based on height and weight.
"Chronic disease risk, such as risk of type 2 or gestational diabetes may be 'programmed' much earlier in life by exposures occurring during developmentally sensitive periods such as puberty, infancy or even intrauterine life," said Dr. Dana Dabelea, a professor at the University of Colorado Denver who studies gestational diabetes but was not involved in this research.
Interventions to address these health issues may need to start earlier to address the risk of diseases like diabetes, Dabelea said by email.
"Women with early menarche are at increased risk of diabetes later in life so they should take additional precautions, especially active lifestyles and maintaining a healthy body weight, to mitigate this increased risk," Dabelea said.
"Supporting healthy environments and behaviors from early in life are important strategies, and promoting healthy eating and physical activity should be a priority for young mothers and schools, and for all women throughout their lives," Schoenaker said.