Explaining menstruation to your daughter is a great way for her to feel comfortable with the changes that are going in her body. It’s also a great way to bond and show her you’re there for her through everything. Here are some menstruation basics to help you explain everything she needs to know about her cycle.
Unique Menstruation Timing
How Hormones Start Her Period
- Most girls get their first period between 11 and 13 years old, but it can start anywhere from ages 8 to 16.
- The average cycle for most girls is 28 days, but it may last from 21 to 35 days and still be “normal.”
- If she has a short cycle, it’s likely she’ll have a period more than once a month. On the flip side, if her cycle lasts longer, she’ll have fewer periods
in a year. Every girl is different!
Hormones are something her body makes and uses to control her body’s functions. As your daughter approaches puberty, a part of her brain called the
pituitary gland begins releasing more and more of certain hormones.
These hormones stimulate her ovaries to produce estrogen and another part of her body to produce other hormones called androgens. These hormones cause a
lot of the physical changes that take place during puberty and during her monthly menstruation cycle.
Phases of the Menstrual Cycle
Women and girls have two ovaries that contain thousands of eggs (ova). During the pre-ovulation (or follicular) phase, hormones stimulate the development
of eggs. At the same time, the soft lining (called the endometrium) of the uterus (the place where a baby can grow) starts to thicken.
Ovulation occurs when a mature egg(s) is released from the ovary. After the egg is released, it travels along the fallopian tube to the uterus. If the egg
is fertilized, it will stick in her uterus and develop into a fetus.
Ovulation usually happens around 10 to 16 days before her next period.
Premenstrual (Luteal) Phase
After ovulation, hormones trigger her body to continue developing the lining of the uterus, in preparation for a fertilized egg. During this phase, if your
daughter were to become pregnant, the egg moves into the uterus, and then attaches to the lining.
If she is not pregnant, the lining of the uterus is shed through the vaginal opening during menstruation.
The womb lining leaves the body through the vagina as a reddish fluid containing blood — typically about a quarter of a cup of blood (although it can seem
like a lot more). This is your daughter’s “period” — it is also called menses — and it will last between three to seven days. The first day of bleeding is
officially day one of her menstrual period. It’s also day one of her cycle (which ends on the first day of her next period.)
- The American Congress of Obstetricians and Gynecologists (ACOG), Patient brochure 49
- ACOG, Patient brochure: midlife transition and menopause
- ACOG, Medical Student Education Module 2008
- Comprehensive Gynecology Review, 3rd edition; edited by F. W. Ling, L. A. Vontver, and R. P. Smith
- Bloom and Fawcett: A Textbook of Histology, 11th edition, by Don W. Fawcett
- Emans, Laufer, Goldstein's Pediatric and Adolescent Gynecology, 4th edition, by S. Jean Emans and Marc R. Laufer)