Reproductive health is an important part of female health, and it’s important for pre-teens and teens to understand how to manage changes that their body will experience during puberty. This includes menarche or the onset of their menstrual cycle. On this week’s On Call for All Kids, Jasmine M. Reese, M.D., assistant professor of pediatrics and director of Adolescent and Young Adult Specialty Clinic at Johns Hopkins All Children's Hospital, talks to parents about important issues on this subject.

When should girls expect to start their menses or what we call period?

Girls should expect to start their menstrual cycle around the age of 12. This typically comes after other physical changes happen such as breast development, growth of body hair and their growth spurt. If they haven’t started their period before their 16th birthday they should be sure to discuss this with their pediatrician.

What timing and frequency should girls expect for their period?

Having a regular menstrual cycle usually means having a period once per month. This is typically about every 21-40 days. As young girls first start their period, their body is still going through hormone changes. This is likely to cause periods to be irregular especially within the first two years after starting. This means that periods can sometimes come more than once per month or skip months in between.

When does it become a problem if a girl’s period is not regular?

If periods are coming too frequently, for example, more than once in a month, lasting longer than seven days, or if flow is very heavy during menses, this can lead to iron deficiency anemia or low hemoglobin levels. Having low iron due to chronic blood loss can lead to a variety of symptoms including feeling weak, tired, low energy, dizziness or even fainting. Heavy periods can sometimes lead to bleeding through sanitary pads, clothing, bed sheets or even missing school or important activities because of flow. If you notice that periods are too heavy or too frequent it is important to discuss with your pediatrician to see if further evaluation or treatment is needed to help regulate your period.

What are treatment options to help regulate menstrual cycles and control bleeding?

Hormonal birth control methods are the most common way to regulate and control menstrual bleeding. We know that hormone birth control is very often used as a contraceptive method; however, these methods have several other non-contraceptive uses and benefits. These include decreasing menstrual flow, decreasing cramping pain, improvement in acne, treating premenstrual syndrome (PMS) and managing polycystic ovarian syndrome (PCOS).

What are safe hormone contraceptive methods that can be used by teens and preteens?

There are a variety of options that can be used and the best one overall is the one that fits your needs and preferences. These hormone methods are all reversible, temporary, and you can decide to change your mind about using them any time. It is important to remember that these methods may vary in effectiveness when used as a contraceptive method.

Some examples include:

• Hormonal pills: A pill is taken orally each day 
• Birth control patch: This is a patch that sticks to the skin, delivers hormones through the skin, and is changed once per week for three weeks
• Vaginal ring: This is a small flexible device that is inserted into the vagina once a month for three weeks
• Depo-Provera shot: This is an injection into the muscle every 12 weeks 
• Hormone-releasing intrauterine device (IUD): This is a tiny, T-shaped device that is inserted into the uterus and can stay in place for three to six years depending on the IUD that is chosen
• Birth control implant: This is a small, thin rod that is inserted under the skin of the arm for three years (one in 10 women stopped using this method because of unfavorable bleeding changes)

What should parents who are hesitant to have their young teens started on hormone contraceptives know to help them make the best decision for their adolescent?

Deciding to have your teen start any new medication can be challenging and you should always ask your doctor about risks and benefits. Risks and benefits of hormone methods can vary by individual depending on their medical history and their use of other routine medications. Parents should remember that heavy and irregular menses can lead to a lot of unwanted and potentially very embarrassing accidents during school, sports or other activities that they want to take part in. Managing this with just supportive measures can be quite challenging and may not work. In severe cases, heavy periods can also lead to hospitalizations and even blood transfusions if too much blood is being lost during menstruation. It is really important to consider the benefits of using a hormone-based method, especially as it relates to teens feeling confident, healthy and overall good about their own body.

On Call for All Kids is a weekly series featuring Johns Hopkins All Children's Hospital experts.