With the first signs of puberty arriving as early as age 8 in some children, early menstruation may be a cause for concern among their parents and caregivers. Emerging research links early menstruation to breast cancer and other health risks later in life. These findings may prompt understandable alarm.
Clinicians should know how to address common questions and provide sensitive, clinically appropriate care when a patient's first period arrives earlier than expected.
Pubertal Milestones and Menstruation
In the late 1960s, researchers W.A. Marshall and J.M. Tanner defined the stages of pubertal development in children and adolescents with "Sexual Maturity Ratings," also known as Tanner Staging. The first sign of female puberty, per the Tanner Stages outlined in StatPearls, is breast development at 8.9 years in Black patients and 10 years in white patients.
In terms of pubertal milestones, menarche typically occurs within two to three years after the appearance of breast buds, according to research from the Journal of Pediatrics. A U.S.-based cross-sectional study in Pediatrics notes the presence of breasts and/or pubic hair in 15 percent of white patients and 48 percent of Black patients by age 8.
According to research from the Journal of Adolescent Health, decades of National Health and Nutrition Examination Surveys reveal a long slide in the age of menarche in girls in the U.S. in all racial groups. The mean age for the first menstrual cycle slipped from 13.3 years in girls born prior to 1920, to 12.4 years in those born between 1980 and 1984. By 2020, an evaluation published in the New England Journal of Medicine found the median age of menarche had ticked down to 11.9 years.
Research also describes variations in first menstruation in racially diverse groups, with the Journal of Adolescent Health pointing out that non-Hispanic Black girls have experienced the largest historical change in the mean age of menarche. The mean age of a first period dropped to 12.2 years among Black girls born between 1980-84 compared to 13.6 years for those born prior to 1920. A 1997 cross-sectional study in Pediatrics similarly reports first menstruation at 12.16 years in Black adolescents compared with 12.88 years in white adolescents.
Rising rates of childhood obesity may also play a role in the timing of puberty and menstruation. Studies across world regions suggest that overweight children now enter puberty and begin to menstruate at a younger age than in the past.
What Is Considered Normal?
Naturally, the parents of children who have menstruated early may wonder if this is normal. It may be reassuring to note that the typical menstrual cycle in youths is irregular, but normalizes over time.
In adolescents, 90 percent of menstrual cycles last between 21 and 45 days, with two to seven days of menstrual bleeding, reports a committee opinion by the American College of Obstetricians and Gynecologists (ACOG). Even so, cycles shorter than 20 days and longer than 45 days may occur. By the third year after menarche, 60 to 80 percent of menstrual cycles are 21 to 34 days long, as is typical in adulthood.
In the first initial years after menarche, immaturity of the hypothalamic–pituitary–ovarian axis often produces anovulatory cycles, notes ACOG. Young patients may experience delays from one cycle to the next.
Still, it is uncommon for adolescents to remain amenorrheic for more than three months. ACOG suggests evaluating young patients with more than three months between periods. Other reasons for clinical investigation include prolonged or heavy bleeding that lasts more than seven days or soaks more than one tampon or pad every one to two hours.
How Does Early Menarche Affect Long-Term Health?
Evidence is emerging that an early first period may pose health risks for your patient later in life. A meta-analysis published in The Lancet found a link between early menstruation and breast cancer risk, although more research is needed in this area.
In 2018, a paper published in the British Medical Journal reported a 10 percent higher risk for cardiovascular disease among women who began menstruating before age 12 compared with those who started at age 13 or older. Studies also suggest ties between early menstruation and early menopause, according to research from Human Reproduction. Finally, research published in the journal Menopause reports that early menstruation may also increase the risk of type 2 diabetes, although body mass index appears to influence this risk.
Notably, menstruation remains an understudied area of medicine, but future research should improve clinical understanding of the potential health impact of what ACOG calls "the fifth vital sign."
Taking Steps for Sensitive Evaluation
Currently, a thorough history with questions about menstruation, symptoms, sexual activity and contraceptive use is part of an initial workup. As these questions are intimate and intrusive, taking a sensitive approach to the inquiry can help put an adolescent at ease. If polycystic ovarian syndrome is suspected, blood tests can be helpful in minimizing some of these questions.
When it comes to evaluating a young patient's reproductive health, it is natural for your patient to feel overwhelmed in a clinical setting. The world of pelvic exams, Pap tests and ultrasounds is foreign to them. Carefully balancing the comfort of a young patient with clinical information-gathering may, in turn, aid in the pursuit of accurate findings about their health.
Ultrasound is well established as the first-line imaging modality for patients of any age. Yet, adolescent patients may find examination with a transvaginal probe to be an intimidating, uncomfortable experience. Consider offering the choice between a transabdominal ultrasound and transperineal ultrasound. Both modalities are internationally recognized and one may be viewed as more culturally sensitive to your patient and their family.
By approaching diagnostic assessment with sensitivity, you can make an accurate diagnosis early on, then work with your young patient and their parents to proactively manage their health as they grow into adulthood.
