"Puberty is the cornerstone of reproductive development," said Marni Sommer, DrPH, MSN, RN, associate professor of Sociomedical Sciences at the Mailman School of Public Health. "Therefore, the transition through puberty is a critical period of development that provides an important opportunity to build a healthy foundation for sexual and reproductive health. Given the importance of this transition, the research is striking in its lack of quantity and quality to date."

The investigators used Qualitative Research guidelines to review the data from peer-reviewed articles with a qualitative study design published between 2000 and 2014. They used a quality assessment form as a further check of the data.

The age of breast development and menarche has declined steadily in the U.S. during the last 25 years, with 48 percent of African-American girls experiencing signs of physical development by age 8. "This trend may mean that increasing numbers of African-American girls are not receiving adequately timed puberty education¬, leaving them uninformed and ill-prepared for this transition," said Ann Herbert, doctoral candidate at the Bloomberg School of Public Health.

Although many of the girls reported being exposed to puberty topics from at least one source - mothers, sisters, or teachers - most felt that the information was inaccurate, insufficient, or provided too late. Girls also reported being disappointed in the information they received from mothers; meanwhile many mothers said they were unable to fully address their daughters' needs. Mothers were uncertain about the right time to initiate conversations, uncomfortable with the topic, and uninformed about the physiology of menstruation. The timing of puberty also influenced girls' puberty experiences.

The researchers noted that despite a strong focus on adolescent sexual health outcomes, such as sexually transmitted infections and teen pregnancy, clinicians and public health practitioners in the U.S. have yet to capitalize on the issues of puberty onset and menstruation as a window of opportunity to improve adolescent sexual and reproductive health. In addition, the current body of research leaves out many topics entirely. "For example, missing are the voices of adolescents with non-conforming gender role and sexual orientation," Herbert said.

Earlier research showed that irrespective of race, higher-income girls had more knowledge about puberty, were more prepared for menarche, and had more positive attitudes about menstruation, strongly suggesting socioeconomic disparities related to preparation for puberty.

"Findings from the current review suggest that low-income girls today expressed a sentiment similar to girls studied in the 1980s and 1990s - a feeling that they were largely unprepared for puberty and menarche," noted Herbert.

"Our review makes it clear that there is a need for new more robust interventions to support and provide information about puberty for low-income girls, something we are considering for the coming years," said Sommer.