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Does the age of your first period affect fertility?

The age at which a girl gets her first period, known as menarche, can have implications for her future fertility. Menarche typically occurs between the ages of 8 and 15, with 12 being the average age. However, getting your period at an earlier or later age can impact your reproductive health down the road.

What is menarche?

Menarche is the start of menstruation and fertility in girls. It signals the beginning of puberty and adolescence. During this time, a girl’s body begins producing the hormones estrogen and progesterone, which trigger ovulation and menstruation. The first period usually occurs around 2 years after breast development begins.

Some key facts about menarche:

  • It typically happens between ages 8 and 15.
  • The average age is around 12.
  • Earlier breast development can signal earlier menarche.
  • It occurs about 2 years after the start of puberty.
  • Periods can be irregular for the first 1-2 years.

The timing of menarche is influenced by several factors, including genetics, body weight, diet, physical activity, and environmental exposures.

Does early menarche impact fertility?

Girls who get their periods at an early age, defined as before age 12, may have reduced fertility later in life. Here’s how early menarche can affect future childbearing:

Shorter reproductive lifespan

The earlier periods start, the sooner a girl will experience menopause. Menopause typically occurs around age 51. So girls who had menarche at age 9 may go through menopause in their late 30s or early 40s, resulting in a shorter reproductive lifespan.

Higher risk of polycystic ovary syndrome (PCOS)

PCOS is a hormonal disorder characterized by infrequent or absent periods, excess androgen, and small cysts on the ovaries. It can interfere with ovulation and make it harder to get pregnant. Girls who matured early are at increased risk for developing PCOS as teenagers or adults.

Greater chance of endometriosis

Endometriosis causes tissue similar to the uterine lining to grow outside the uterus, leading to pain and reduced fertility. Early menarche raises the odds of developing endometriosis later on.

Higher estrogen exposure

Starting periods early means greater lifetime exposure to estrogen. High estrogen levels have been associated with conditions like uterine fibroids that can impair fertility.

Increased risk of chronic health issues

Obesity, diabetes, heart disease and other chronic health problems are more common in women with early menarche. These conditions can negatively impact ovarian function and fertility.

Potential emotional immaturity

Girls who get their period before peers may be less emotionally ready for it. The stress of early puberty can potentially affect relationships, sexual behavior and future parenthood plans.

Does late menarche decrease fertility?

On the other hand, delayed menarche, defined as after age 15, can also cause fertility issues later on:

Ovulation problems

Girls who start menstruating late often have issues with irregular or absent periods. This reflects problems with ovulation that make it difficult to get pregnant. Even after periods become regular, ovulation may not occur every cycle.

Polycystic ovary syndrome

Like with early puberty, late menarche also increases the chances of developing PCOS. The hormone imbalances involved in PCOS interfere with normal ovulation.

Uterine and ovarian developmental issues

A late start to periods can signify that the uterus and ovaries did not develop properly. Structural or anatomical abnormalities in these organs can prevent conception and implantation.

Primary ovarian insufficiency

Primary ovarian insufficiency describes when ovaries stop functioning normally before age 40. It leads to low estrogen levels and irregular/missed periods. Women who had late menarche have higher odds of developing primary ovarian insufficiency.

Risk of chronic health problems

Delayed sexual development raises the risk for many chronic diseases later on. Thyroid disorders, diabetes, obesity and autoimmune conditions become more common. These problems can directly or indirectly cause fertility troubles.

Key takeaways

Here are the key points to understand regarding menarche timing and fertility:

  • Early periods (before 12) tend to predict shorter reproductive lifespan and higher chances of conditions like PCOS and endometriosis.
  • Late periods (after 15) are linked with ovulation abnormalities, ovarian issues, and insufficiency.
  • The lowest risks for fertility problems occur with menarche between 12-13 years old.
  • Extremes on either end can signify that pubertal development did not occur as expected.
  • Menarche age alone does not definitively determine future fertility, but is one factor among many.
  • Other influences include genetics, environmental aspects, chronic disease risk, and sexual health factors.

What is a normal menarche age?

The average age falls between 12 and 13. However, menarche anywhere from 8 to 15 can still be considered normal.

Here are the rough percentiles for age at first period:

Age Percentile
8 years 5th
10 years 25th
12 years 50th (average)
13 years 75th
15 years 95th

As this data shows, most girls get their first period between ages 10 and 13. By age 15, almost all girls have started menstruating.

Factors influencing menarche timing

A number of factors can influence the timing of a girl’s first period:


Genetics accounts for about half of the variation in menarche age. If a mother started menstruating early or late, her daughter often follows a similar pattern. But genes alone do not determine menarche timing.

Body weight

Girls who have higher body mass indexes (BMIs) and more body fat tend to begin puberty and menstruation earlier. Excess body fat produces more estrogen.


A diet with adequate nutrition and calories is needed to initiate puberty at the appropriate time. Lack of key vitamins and minerals can delay sexual development.

Physical activity

Moderate to high levels of exercise are linked to later menarche. However, too much strenuous activity and low body weight may excessively postpone maturation.

Environmental factors

Chemical exposures, nutrition, light exposure, stress and socioeconomic status during childhood can all influence menarche timing. The effects are complex and not fully understood.

Medical conditions

Serious chronic illness as a child can delay puberty and menarche. Examples include cystic fibrosis, renal disease, diabetes, and autoimmune disorders. But these only impact menarche timing if diagnosed before puberty begins.

Common concerns

Some common questions and concerns regarding age at menarche:

My daughter got her period at age 9. Could this mean she has a health problem?

Getting your period before age 10 outside of normal pubertal changes may signify an underlying issue. Causes can include hormonal imbalances, tumors, medications, or foreign objects in the vagina. See a pediatrician to determine if there is a health reason for early menarche.

I’m 16 and haven’t gotten my period yet. Does this mean I can’t have children?

No, but you should be evaluated to determine the cause of delayed menarche. Simple hormone testing can help identify any problems. Treatment may be needed to trigger menstruation. Lack of periods by age 16 likely relates to a medical condition impacting normal sexual development.

My sister had a late first period. Am I likely to as well?

Possibly, given the strong genetic influences on menarche timing. However, environmental factors also play a role, so you may not follow the same exact pattern. Tracking your development through puberty can help predict when you will get your period.

I got my period at 13. Is that considered early or late menarche?

Thirteen is right around the average age, so that is considered normal timing for menarche. Early is before 12, while late is after 15 years old.

Can I do anything to influence when my period starts?

Not significantly. The timing of menarche is primarily determined by your genetics, health status, body composition, and early life environment. Eating well, minimizing stress, and staying active can support normal timing – but no specific actions will drastically change menarche age.

When to see a doctor

Consult your pediatrician or doctor if:

  • No breast development by age 13
  • No period by age 15
  • Periods started before age 8
  • Periods suddenly stop for over 90 days
  • Menstrual problems or irregularities persist beyond the first 1-2 years after menarche.

Seek prompt care for early menarche accompanied by symptoms like headache, vision issues, nausea, sexual development, or vaginal bleeding.


In summary, the age at which a girl gets her first period can influence certain aspects of her reproductive health and fertility later in life. Very early or late menarche may be a sign of medical issues impacting pubertal development. However, menarche timing alone does not definitively determine future childbearing potential. Regular periods between the ages of 12 and 15 suggest normal maturation. While menarche age can positively or negatively correlate with fertility based on large population studies, it should not cause alarm about an individual’s ability to conceive.