What is ovulation?

Ovulation is an integral part of awoman’s menstrual cycle. Although it occurs about midway in the cycle, whichbegins on the first day of a woman’s period, it affects the entire cycle.However, this process can be split into an accelerated time of activity beforean egg is released from an ovary, and a time of deceleration, after the eggor ovum is released.

As a woman begins her period, her body isin the follicular phase of the process. The body, or more specifically,the hypothalamus gland, recognizes this pre-ovulation state andreleases hormones to the pituitary gland. On receiving these signals, thepituitary gland produces a hormone called follicle stimulating hormone(FSH), which will allow follicles in an ovary to start maturing into an egg.

During ovulation, generally only oneegg is released. Even though several follicles along the ovaries maybegin to mature, only one ovum actually will be released. The rest of thestimulated follicles simply disintegrate.                

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Once the follicles have produced a fullymature ovum, estrogen is released into the body. This signal that thebody is ready to ovulate must be met by a hormone response from thehypothalamus and pituitary gland. They in turn release luteinizing hormone,which causes the egg’s release.

The release of estrogen and of luteinizinghormone tends to result in some women experiencing pre-menstrual syndrome(PMS). Women may also have cramping during this time, or notice a bit ofspotting. The body temperature does rise slightly during this time period, andvaginal mucus becomes thicker. Many women may also feel the desire to bemore sexually active prior to ovulation.

From a scientific standpoint, rise in bodytemperature, vaginal mucus and interest in sexual intercourse are allbeneficial when one wants to produce a baby. They can help predict, dependingupon the regularity of one’s cycle, when one is most likely to get pregnant.

Once the ovum is released and travels downone of the fallopian tubes, the process is complete and the body entersthe luteal phase of the menstrual period. Estrogen and luteinizinghormone levels drop, and the body begins to produce progesterone.The uterus is lined with a thickened material that assists in eggimplantation.

As progesterone is released, this liningwill essentially thicken a bit more. However, the body also recognizes when theovum is not fertilized and dissolves. Unfertilized ova tend to live for about24 hours after the egg reaches the uterus. Some 12-16 days after a womanovulates, this lining will be shed from the body at the beginning of a woman’snext menstrual cycle.

Although a woman's fertile time can sometimesoccur on a predictable schedule, this is not always the case. Stress or illnesscan delay or force early ovulation, which can cause either late or earlyperiods. Adding to the difficulty to pinpoint exact time of the egg is releasedand the window of fertility, it is important to note that male sperm canlive for several days in the uterus. Pregnancy can occur if sexual intercoursetakes place two to four days before the egg is released, and at least a dayafter ovulation.