Ovulation refers to the release of an egg during female menstruation.
An egg discharges a part of the ovary called the ovarian follicle. The egg is also known as gamete ovum, oocyte, or female. This is released on maturity maturity only.
The egg moves down the Fallopian tube after release, where it can be met by a sperm and become fertilized.
During the menstrual cycle, ovulation and hormone release are regulated by a part of the brain called the hypothalamus. This sends out signals to secrete luteinizing hormone ( LH) and follicle-stimulating hormone (FSH) to the anterior lobe and pituitary gland.
Knowing when ovulation is likely to occur is beneficial, because a woman is most fertile during this period, and more likely to conceive.
Throughout the menstrual cycle the ovulation process is characterized by a duration of high hormones. It is divisible into three phases:
- The periovulatory or follicular phase: A layer of cells around the ovum begins to mucify, or become more like mucus, and expand. The uterus lining begins to thicken.
- The ovulatory phase: Enzymes are secreted and form a hole, or stigma. The ovum and its network of cells use the stigma to move into the fallopian tube. This is the period of fertility and usually lasts from 24 to 48 hours.
- The postovulatory or luteal phase: LH is secreted. A fertilized egg will be implanted into the womb, while an unfertilized egg slowly stops producing hormones and dissolves within 24 hours.
The uterus lining often starts to break down and prepares to leave the body during menstruation, or menstruation.
When does it occur?
A woman’s menses last from 28 to 32 days on average.
The beginning of every cycle is considered to be the menses’ first day. The release of the egg happens normally 12 to 16 days before the next cycle is due.
Most females start menstruating between the ages of 10 and 15 years. Around the same time, they continue ovulating and are capable of conceiving. It is a time which is called the menarche.
Ovulation usually ceases after menopause, on average between the ages of about 50 and 51 years, although it also happens in the period leading up and menopause. It is called peri-menopause.
There are many signs a woman ovulates.
The cervical mucus rises in thickness during ovulation, and becomes thicker due to elevated levels of estrogen. Around the most fertile stage of a woman the cervical mucus is often compared to egg whites.
Slight changes in body temperature can also occur. It is driven by the progesterone hormone, which is secreted at release of an egg. Females are typically most fertile for 2 to 3 days before their average temperature reaches.
The gradual increase in temperature can be monitored using a basal thermometer. It can be purchased online, or in most drug stores.
Many people experience a slight ache in the lower abdomen or pang of discomfort. It is known as pain in the Mittelschmerz. This can last several minutes to a couple of hours.
Eventually, predictor kits of ovulation, available in drug stores, can detect the rise in luteinizing hormone ( LH) in urine just before ovulation.
The aim of an ovulation calendar is to help a woman predict when she will be most fertile.
There are several websites and apps which support this process by asking questions such as:
- When was the beginning of your last menstrual cycle?
- How long do your menstrual cycles generally last?
- How long is your luteal phase, or the time between the day after ovulation to the end of your cycle?
Women usually find it useful to document or map menstrual details for calendar entry. Holding menstrual cycle monitor can also be crucial to highlighting any irregularities.
Issues with the ovulation process can lead to infertility or difficulty conceiving.
Polycystic ovarian syndrome
A woman with PCOS has swollen ovaries, frequently with small, fluid-filled cysts on them. This can contribute to an imbalance in the hormone which can hinder ovulation.
Certain signs can include insulin resistance, obesity, hair growth that is irregular and acne.
PCOS is female leading cause of infertility.
This is when the FSH and LH hormone output is interrupted. The hormones that induce ovulation are these. That can affect the process of menstruation.
It is normal to have irregular menstrual cycles and amenorrhea which means no menstruation at all.
Hypothalamic dysfunction can include severe physical or emotional stress, excessively high or low body weight or substantial weight gains or losses.
Excessive exercise, low body weight and hypothalamus tumors may also cause hypothalamic dysfunction.
Premature ovarian insufficiency
It is when development of eggs ceases prematurely, leading to a decrease in levels of estrogen.
This may be due to an autoimmune disease, genetic or environmental toxins.
Usually it affects women before they are 40 years old.
Hyperprolactinemia, or excess prolactin
Women may produce excessive quantities of prolactin in some cases, such as the use of medicine or an abnormality in the pituitary gland that produces hormones.
It can in effect contribute to a decline in the development of estrogen.
Another less common cause of ovulatory dysfunction is excess prolactin.
Fertility drugs can cause ovulation.
These drugs are known to control ovulation, or cause it. Doctors may prescribe the following for the treatment of anovulation, or for ovulation to cease.
Brand names are in brackets.
- Clomiphene citrate (Clomid): This oral medication increases pituitary secretion of FSH and LH, stimulating ovarian follicles.
- Letrozole (Femara): This works by temporarily lowering a woman’s level of the hormone progesterone to stimulate ovum production.
- Human menopausal gonadotropin or hMG (Repronex, Menopur, Pergonal) and FSH (Gonal-F, Follistim): These injectable medications are known as gonadotropins and stimulate the ovary to produce several eggs for ovulation.
- Human chorionic gonadotropin or hCG (Profasi, Pregnyl): This matures eggs and subsequently triggers their release during ovulation.
- Metformin (Glucophage): This medication is typically used in women with PCOS to treat insulin resistance and increase the chances of ovulation.
- Bromocriptine (Parlodel) and Cabergoline (Dostinex): These medications are used in cases of hyperprolactinemia.
Be mindful that taking fertility drugs will make you more likely to have twins or triplets. This can cause side-effects, including:
- abdominal pain
- hot flushes
- heavy menstrual flow
- tenderness in the breasts
- vaginal dryness
- increased urination
- mood swings
When these get serious, a doctor can consider other options.