By Laura K. Grubb, MD

My daughter is 13 and a half and has not experienced her first period yet. Her next well visit is still 6 months away: Should I call her pediatrician and schedule an appointment in the meantime? I'm unsure of the typical age range of first periods these days. Should I be concerned?

Dear Reader,

Your daughter's first period, or lack thereof, can be a common cause for concern among parents. However, most young women get their first period between the ages of 11-15, with 12 ½ being the average.

There are a number of contributing factors that may determine when a young woman begins her period: family history, ethnicity, health status, and nutrition all play into the expected timeline. During this time they may also be experiencing other signs of puberty, but not their period. Other signs of puberty in young women include breast development, hair growth, and growth spurts. Beginning a period is commonly seen as the "last part of puberty." Unless there are no other signs of puberty, a young woman who has not begun her period by age 13 is not a particular cause for concern.

For many young women who have not yet experienced their first period, there are two very common causes for the delay. The first is a "constitutional delay," which simply means the period has not yet started and that there are no underlying medical problems or concerns. The second most common delay is due to nutritional issues or deficiencies.

If a 15-year-old has not yet started her period, a doctor would most likely complete an evaluation that includes a comprehensive review of her health history, a physical exam, testing to rule out pregnancy, and possibly other labs or studies. If your daughter's doctor recommends a full evaluation, you can be prepared to help by providing a detailed family history that outlines any previous or family illnesses, patient's nutritional status, and any underlying medical conditions or concerns.

I recommend having conversations about puberty with your children (boys and girls!) before it starts so they know what to expect and can feel comfortable asking questions. I often advise parents to read books with their children. One of my favorite books for girls and young women is The Care and Keeping of You: The Body Book from American Girl. It is a great resource for young girls, and there are two versions based on age group. Books like this are great to sit down and read with your child on a daily basis, but also to leave with your child to read on their own. They may have questions not just about puberty, but about all things concerning growing up and becoming a teenager and young adult.

Puberty is a difficult time for young men and women and their parents, and there are always a lot of questions. It is always best to reach out to your child's pediatrician if you have continued concerns.

Laura K. Grubb, MD MPH, is director of adolescent medicine at Floating Hospital for Children at Tufts Medical Center and an assistant professor of pediatrics and assistant professor of public health and community medicine at Tufts University School of Medicine.