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First menstrual cycle: is it normal or not?

Published on October 21, 2014 at 14:41 / Updated on July 22, 2019 at 14:36

The onset of the first menstrual cycle is a very important stage in the life of a teenage girl. Mixed feelings and endless questions usually permeate this time in a girl’s life, even if she has prepared for it. The question that most often comes up: “Is it normal?”

The onset of the first menstrual cycle is a very important stage in the life of a teenage girl. Mixed feelings and endless questions usually permeate this time in a girl’s life, even if she has prepared for it. The question that most often comes up: “Is it normal?”


The American Academy of Pediatrics has issued a clarification on this subject. Contrary to popular belief, the first period or menarche does not in fact occur at an earlier age than it did in the past. Since the 1950’s, young girls in developed countries have their first menstrual cycle around the ages of 12 or 13, approximately two or three years after breast budding (development). It is estimated that 90% of teenage girls are menstruating by age 14, and 98% by 15. Young girls of African and Hispanic descent usually have their first period a few months earlier than Caucasian females do.


Menstrual cycles are often irregular throughout adolescence, particularly between the first and second cycle. Most cycles vary between 21 and 45 days starting in the first year. A cycle begins on the first day of the period and ends on the first day of the next period. Normal bleeding will last between two and seven days.


Menstrual flow is generally qualified as medium. Experts estimate that approximately 30 mL of blood is lost during a menstrual cycle, or the equivalent of two tablespoons. However in reality, it is quite difficult to measure the actual quantity. Most young girls report changing their chosen menstrual hygiene product (pad or tampon) between three and six times a day. It is normal for the menstrual flow to be more abundant during the first few days of the cycle, and to decrease thereafter.


It is also normal to have abdominal cramps and lower back pain during a period. Taking analgesics such as acetaminophen or ibuprofen can help relieve the discomfort. However, if the pain pins a young girl to bed or prevents her from going to school, you should discuss the situation with a physician.


Paediatricians have identified 11 warning signs that require medical consultation: - no menstrual cycle in the three years following breast budding; - no menstrual cycle at the age of 13 if the young girl does not exhibit other signs of puberty (breast budding, development of pubic hair, enlargement of hips); - no menstrual cycle at the age of 14 if the young girl exhibits signs of hirsutism (excessive hair on the face, chest, back, stomach, thighs or arms); - no menstrual cycle at the age of 14 if the young girl exercises excessively or has an eating disorder (anorexia or bulimia); - no menstrual cycle a the age of 14 if genital or urinary problems are suspected; - no menstrual cycle at the age of 15; - regular monthly menstruations that become totally irregular; - menstruations that occur at intervals shorter than 21 days or longer than 45 days; - menstruations that last longer than 7 days; - menstruations that occur at an interval of 90 days, even if only once; - excessive menstrual flow that require a change of pad or tampon more than once every hour or two.


According to this group of paediatricians, monitoring menstrual cycles should be considered an additional vital sign in women, as important as blood pressure, heart rate or breathing rhythm. Being able to recognize what is normal or abnormal can help diminish the anxiety caused by incessant questioning and detect potential health problems that can benefit from early treatment.


Menstrual cycles are not useless; rather they are an excellent indicator of a woman’s general health condition. Often regarded as a cumbersome problem in early adolescence, they take on a whole different role later in life. Take a woman’s word for it!

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