The start of menstruation is a momentous event in a girl's life. Some girls greet those first drops of blood with joy or relief, while others feel bewildered and shy. Whatever the reaction, the arrival of the first period holds the same meaning for every girl: It's proof that she's becoming a woman.

On average, most girls start their periods when they're 12 or 13 years old (although some begin earlier or later). But if you wait until your daughter gets her period to talk to her about menstruation, that's too late.

So, how do you discuss menstruation and offer education, as well as guidance and support, before the big day even arrives? Or, what do you tell your son? (Boys have questions, too.) Before you can discuss menstruation, it's important to have a good understanding of how the process works.

What's Menstruation?

In the early 1900s, girls generally reached menarche (the medical term for the first period or the beginning of menstruation) at age 14 or 15. For a variety of reasons, including better nutrition, girls now usually start to menstruate between the ages of 9 and 16. But menstruation isn't just about having a period. It's a sign that a girl is physically capable of becoming pregnant.

During the menstrual cycle, hormones are released from different parts of the body to help control and prepare the body for pregnancy. That preparation begins when the ovaries (two oval-shaped organs that lie to the upper right and left of the uterus, or womb) produce the hormones estrogen and progesterone. These hormones trigger certain changes in the endometrium (the lining of the uterus). Then, other hormones from the pituitary gland stimulate the maturing and release of the egg, or ovum, from the ovary. The release of the egg is called ovulation, and it occurs at the midpoint in the cycle — usually day 14 of a 28-day cycle, for example. From the ovary, the egg moves into one of the fallopian tubes (the two tubes that connect the uterus to the ovaries).

If the egg is fertilized by sperm, the fertilized egg will take about 5 days to travel down the fallopian tube and attach to the thick, blood-rich lining of the uterus. If it's not fertilized, the egg begins to fall apart, the estrogen and progesterone levels drop, and the uterine lining breaks down and is shed — this bleeding is what's known as a period.

A menstrual cycle lasts from the first day of one period to the first day of the next. The typical cycle of an adult female is 28 days, although some are as short as 22 days and others are as long as 45. Periods usually last about 5 days, although that can vary, too. During a period, a woman passes about 2–4 tablespoons (30–59 milliliters) of menstrual fluid.

For the first few years after menstruation begins, cycles are often irregular. They may be shorter (3 weeks) or longer (6 weeks), or a young woman may have only three or four periods a year. The absence of periods is called amenorrhea. A girl should see her doctor if she hasn't started menstruating by age 16, or 3 years after her first signs of puberty appeared.

So, how will you know when your daughter might start menstruating? You'll probably be able to see physical changes that signal she's getting close to starting. Breast development is usually the first sign that a girl has entered puberty. It's usually followed by the growth of some pubic hair.

About a year after breast development begins, most girls enter into a phase of rapid growth. They'll get taller and curvier, and their feet will grow. Then, about a year after the growth spurt begins and about 2 years after breast development starts, the first period arrives.

Timing Is Everything

It's probably best to avoid "The Talk" about menstruation. Instead, try to spread it out into lots of smaller conversations — education about how the human body works should be continuous. Otherwise, too much importance is placed on a single discussion and the information can be overwhelming. In other words, kids reaching puberty should already know what a penis and vagina are.

Even toddlers begin asking questions about their bodies, and parents should answer them honestly. But how specific you are with the details should depend on your child's maturity and ability to understand, particularly if you're talking to boys about girls.

Throughout childhood, kids ask many questions and each is an opportunity for parents to advance their child's knowledge. Doing so not only gives kids the information they need when they ask for it, but also lets them know that their parents are available for and comfortable with these discussions.

But you shouldn't necessarily wait for your child's questions to talk about puberty and menstruation. Ideally, by the time they're close to puberty, both girls and boys should have full knowledge of the changes that will take place in their bodies. Why? Kids really want to learn about most things from their parents. And you can be sure that they'll also hear their friends discuss these changes.

By providing kids with good information, parents will know that they're well-informed and able to sort out any misinformation. Kids can often make certain aspects of puberty — menstruation, especially — sound bad and scary; and if that's the only information your child has, then that's what he or she will believe.

It's also important for parents to paint the process of menstruation in a positive light. If a mother refers to her period as "the curse," her daughter might take away a negative impression of the whole experience. Instead, mothers can explain that monthly periods are a natural and wonderful part of being a woman. After all, without them, women couldn't become mothers.

Explaining that everyone is different is also key. For example, your daughter may be concerned that her body is changing more quickly — or more slowly — than her friends' bodies.

In addition to understanding how menstruation works, girls need to be familiar with feminine-hygiene supplies (sanitary pads and tampons) and they should know that sometimes periods may cause cramps when the muscles of the uterus contract.

Another reason kids need to know about menstruation at an early age is that sexually active girls can get pregnant before they start menstruating. Sometimes ovulation (the release of an egg from an ovary) can happen just before a girl is about to have her first period. This means that she can be fertile and become pregnant even though she hasn't yet menstruated.

Common Questions Kids Ask About Periods

Kids — both girls and boys — often have lots of questions about menstruation, such as:

• How come only girls have periods? Explain that boys change in different ways during puberty, like the deepening of their voices and the growth of facial hair. Getting her period means a girl can have a baby.
• Do girls have their periods for the rest of their lives? No, a woman stops having her period usually between the ages of 45 and 51, which means she will no longer be able to become pregnant (at least without the help of some fancy reproductive technology, that is!).
• How long does a period last and how much blood is there? It varies for each girl, but some have their period for 3 days and others have it for a week. Periods can be light, moderate, or heavy, and there can be a total of 2–4 tablespoons (30–59 milliliters) of blood or up to as much as half a cup (118 milliliters). And this can vary from period to period in the same girl.
• Are pads or tampons better? In choosing between the two, what matters is a girl's physical and emotional comfort. A tampon can be uncomfortable in the years right after menstruation starts, when the pelvis and vagina are still growing. Usually, girls are more comfortable using pads at first, but they may want to start using tampons when they get older (although they don't need to wait to use tampons until a certain age). Their friends may have started using them, and the freedom tampons can give may be appealing. Each box of tampons includes instructions, so be sure to read them with your daughter.
  
  Although the first few times using a tampon can be frustrating, explain to your daughter that it will soon be easy with a little practice. Because the muscles of the vagina can become tense when a girl is nervous, it can be difficult to insert a tampon at first. It's important to relax as much as possible. It may also help to start with a slim tampon with an applicator because they can be easier to insert.
• Do girls have to stop playing sports or swimming while they have their periods? Girls should understand they can do everything they normally would do — as long as they're comfortable. For example, girls who swim may prefer to wear a tampon so they can continue to practice while menstruating.
• What's toxic shock syndrome (TSS)? TSS is a rare but serious bacterial infection that's associated with tampon use. Fortunately, TSS can almost always be prevented by changing tampons regularly and by using the smallest size possible (for example, "slender regular" instead of "super plus"). A reasonable precaution is to change tampons every 4 hours or more frequently if the blood flow is heavy.
• Do girls always have cramps with their periods? Concern about cramps is a big issue for some girls. But until girls start their period, it's unknown whether they will have cramps. It's important to tell girls that cramps don't usually last long. Sometimes, a hot water bottle or a hot bath can help ease discomfort. Some find that deep breathing and exercising help, too. If cramps become too uncomfortable, your daughter might want to take an over-the-counter (OTC) medicine like ibuprofen (such as Advil or Motrin).
  
  Having cramps for a day or two each month is common, but signs of dysmenorrhea — severely painful menstruation that interferes with a girl's ability to attend school or study or sleep — or other menstrual problems should be discussed with your child's doctor.
• What's PMS? Premenstrual syndrome (PMS) includes physical and emotional changes (mood swings and irritability, tension, bloating, and breast tenderness) that can occur during the time right before some girls get their periods. But girls usually don't develop symptoms associated with PMS until several years after menstruation starts — if ever. For those who do experience PMS, plenty of rest, exercise, and eating a balanced diet may help.
• Do girls need to douche or use deodorant spray when they have their periods? No. In fact, douching can increase a girl's possibility of infection by disrupting the normal balance of bacteria in the vagina.

Tips for Talking

Just as parents might be slightly embarrassed to talk with their children about menstruation, kids and teens may find it difficult to let mom and dad know their questions or concerns. If talking about menstruation is awkward for you, here are some ways to make discussions a little easier and more open:

• Look for good books and videos or DVDs that can help foster a more comfortable and educational conversation.
• Speak to your family doctor about ways to talk about menstruation and puberty.
• Brush up on the facts of menstruation and have information readily available for your child to look at or read.
• Coordinate your conversations with the health lessons and sex education your child receives in school. Ask your child's teacher about his or her plans and for any advice.
• To break the ice, try asking your child some questions that will help you both ease into discussions. Ask what kind of questions he or she has while you walk down the feminine-hygiene products aisle at your grocery store or while you watch a commercial for pain relievers advertised to alleviate symptoms of PMS.
• If you hear your child mention something related to getting a period, spur a conversation by asking where the information came from. Questions can be a great way to set the record straight on any misconceptions your child might have.
• Before you take your preteen daughter for a routine checkup, let her know that the doctor may ask if she's gotten her period yet. You can then ask if she has any concerns or questions about getting her first period.

It's important to tell kids the truth about menstruation in an age-appropriate way and to be comfortable with the accuracy of that information. Don't be put off by their questions — they're probably the same questions you had at that age, and now you can answer them.

Reviewed by: Barbara P. Homeier, MD
Date reviewed: March 2005