INTRODUCTION
This is the first menstrual cycle of a girl and usually occurs between the ages of 10 – 15 years. However, some girls achieve menarche at 8 – 9 years, while others may have it delayed beyond 16 years.
Menarche usually signals the beginning of a female’s reproductive life. However, most of the early menses are not associated with ovulation hence the cycle intervals are wide apart and unpredictable. Ovulation usually occurs when the cycle becomes stable and predictable.
The event which triggers menarche to occur is still unknown. However, it is known that the hypothalamus and pituitary glands secrete hormones [FSH and LH], which stimulate the ovaries leading to the production of estrogen. The estrogen produced by the follicles acts on the lining of the uterus to make it proliferate and grow. It also causes the uterus to grow in size. About 14 days from the onset of menses, there is a surge of hormones leading to ovulation [release of the eggs]. Following ovulation, the follicle gets converted to the corpus luteum and starts secreting progesterone which converts the proliferative endometrium to secretory. The secretory endometrium is conducive for implantation in the event of pregnancy occurring. If no pregnancy occurs, this secretory endometrium sloughs off as menstrual blood in a predictable pattern.
In very young girls because the hypothalamus and pituitary glands are not well developed, stimulation of the ovaries are not adequate leading to insufficient production of estrogen, thus leading to absent ovulation. Hence, the cycle intervals are not regular and unpredictable.
EVENTS AROUND MENARCHE
Menarche usually is the end stage of events surrounding puberty. These events commence with:
- Development of breast buds
- Development of pubic hairs
- Presence of pimples [acne]
- Development of hair around the armpit
- Rapid growth, girls get taller
- First period [menarche]
CHALLENGES
Menarche could be delayed beyond the age of 16 years. When this happens it is called primary amenorrhea. It could arise as a result of several disorders or diseases.
WHEN TO SEE A DOCTOR
You are advised to see your doctor if you experience the following.
- If you have not seen your menses at age 16 years or more
- If at age 16 years you have not experienced the events around puberty [pubic hair, axillary hair, rapid growth]
- If you have your first menses before age 10
