ovulationOvulation is the release of the secondary oocyte (the egg cell, ovum or female gamete) from the ovary. Ovulation is the release of the secondary oocyte (the egg cell, ovum or female gamete) from the ovary.


Female menstrual cycle is a process that makes female organism ready for conception, because in the middle of the cycle ovulation takes place. It occurs after the follicular phase on the 14th day of the cycle, although it was reported to vary widely.

Estrogen levels reach their highest level at the end of the follicular phase. This causes an increase of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the serum. This process continues 24 – 36 hours, as results the ovarian Graaf’s follicle ruptures and the oocyte is released from the ovary via the oviduct, than travels to the uterus.

During the following luteal phase may occur the fertilisation of the egg. Endometrium is thickened to nourish the zygote. If the conception doesn’t happen, the uterine lining laminates and the menstrual bleeding occurs.The few days before and after the ovulation (10 – 18 day of a 28-days cycle) are considered to comprise the fertile phase. After the ovulation an egg remains in the female reproductive organs for 12 – 24 hours if it’s not fertilized. It was estimated that the sperm may remain fertile in the woman reproductive system up to 7 days.

Signs of ovulation

• Discharge changes – the mucus of the cervix becomes thicker;

• Body temperature – average body temperature increases before the ovulation and remains increased during the luteal phase;

• Mittelschmerz  (derived from German “middle pain”) – the pain in the abdomen during;

• Senses – many women experienced a heightened perception of smell during it;

Libido – in the days prior to it, females experience increased sexual desire;

See also: Menorrhagia, test

Related disorders

According to the World Health Organization (WHO)  there are four groups of this disorders

• WHO group I: Hypothalamic–pituitary-gonadal axis failure.

• WHO group II: Hypothalamic–pituitary-gonadal axis dysfunction. Polycystic ovary syndrome (PCOS), the most common of these diseases, is characterized by the elevated androgens level in females. It causes irregular or no menstrual periods, heavy periods, abnormal body and facial hair, acne, pain, infertility, and  thick, velvety skin.

• WHO group III: Ovarian failure.  Premature ovarian failure – the ovarian failure that occur in females younger than 40. Usually the triad is seen which includes amenorrhea, hypergonadotropism, and hypoestrogenism.

• WHO group IV: Hyperprolactinemia is characterised by the elevated level of prolactin in the serum (higher than 500 mIU/L). This leads to hypoestrogenism, anovulatory infertility and decreased menstruation, absence of menstruation (amenorrhea) or its irregularity. Women begin producing breast milk (galactorrhea), althoough they are nr pregnant neither nursing. Vaginal dryness makes the intercourse painful or difficult.

Menstrual disorders related to ovulation are oligoovulation and anovulation.

• Oligoovulation – infrequent or irregular (less than 8 cycles a year).

• Anovulation – the absence of ovulation. It begins as the irregularity of menstrual periods. Anovulation can cause the periods cessation (secondary amenorrhea) or excessive bleeding known as dysfunctional uterine bleeding. Anovulation is usually the symptom of PCOS, Cushing syndrome, hyperthyroidism, hypothyroidism, adrenal insufficiency etc.