The woman’s menstrual cycle


The woman’s menstrual cycle

Most women wanting to get pregnant are very concerned about when ovulation takes place and when the chances of getting pregnant are therefore greatest. You are always welcome to contact our specialists if you need individual advice.


The menstruation is controlled by hormones

Already at birth, the girl’s ovaries contain hundred thousand eggs, which remain inactive until puberty, when she begins to develop a menstrual cycle.

The woman’s regular menstrual cycle is between 24-35 days and can be divided into three phases. It is a complex process that is primarily controlled hormonally in the brain, as the mesencephalon (midbrain) sends signals to the pituitary gland (hormone-producing gland in the brain) that stimulates the production of the sex hormones FSH (follicle- stimulating hormone) and LH (luteinising hormone).

The menstrual cycle

First phase

When the production of FSH increases, this results in maturation of an egg in the ovaries. The egg is located in an egg sac (follicle) which forms the female sex hormone oestrogen. Oestrogen builds up the endometrium.


Approximately 14 days before you expect your menstruation, the follicle is mature and now produces large quantities of oestrogen. This causes the pituitary gland to excrete large quantities of the sex hormone LH, which causes the follicle to burst and ovulation to occur. The remnants of the burst follicle (the yellow body) now produce the hormone progesterone, which helps to maintain pregnancy if the egg is fertilised.

Second phase

If a sperm cell manages to fertilise the egg within approximately 24 hours, it will wander through the fallopian tubes down into the uterine cavity and attach itself to the endometrium after five days. If the woman becomes pregnant, she produces hCG (pregnancy hormone).
If the egg is not fertilised, it will be lost and there will be a decrease in the progesterone and oestrogen hormones, there is desquamation of the endometrium and menstruation will begin.

Optimal time for fertilisation

After ovulation, the egg can be fertilised for approximately 24 hours. Sperm can survive for approximately 48 hours after intercourse. Therefore, the optimal time for fertilisation starts two days before ovulation and ends one day after ovulation. I.e. approximately 14-16 days before the woman expects her menstrual period.

ALERIS HAMLET INTERIOR V080 2 Aspect Ratio 4x3

Visit us for a consultation