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The menstrual cycle

The menstrual cycle refers to the changes and preparation that a woman's body goes through to prepare for pregnancy. About once a month, the uterus grows a new lining (endometrium) to get ready for a fertilized egg. When there is no fertilized egg to start the pregnancy, the uterus sheds its lining starting off the monthly menstrual bleeding also called menstrual period.

The menstrual cycle is from Day 1 of bleeding to Day 1 of the next instance of bleeding. The average cycle is 28 days, although it is perfectly normal to have a cycle that is as short as 21 days or as long as 35 days. A regular menstrual cycle is an important element of successful conception.

Hormones control a woman's menstrual cycle and this cycle is comprised of three distinct phases.

The Menstrual Cycle Chart The menstrual cycle
Phase 1 - The Follicular Phase

This phase begins on Day 1 of the menstrual period and lasts until ovulation. The brain's hypothalamus and pituitary gland send hormone signals that get the ovaries and uterus ready for pregnancy. Through the influence of a rise in follicle stimulating hormone (FSH) during the first days of the cycle, a few ovarian follicles are stimulated. These follicles, which were present at birth and have been developing for the better part of a year in a process known as folliculogenesis, compete with each other for dominance. Under the influence of several hormones, all but one of these follicles will stop growing, while one dominant follicle in the ovary will continue to maturity. The follicle that reaches maturity is called a tertiary, or Graafian follicle, and it forms the ovum.

As they mature, the follicles secrete increasing amounts of estradiol, an estrogen. The estrogens initiate the formation of a new layer of endometrium in the uterus, histologically identified as the proliferative endometrium.

Phase 2 - The Ovulatory Phase

This is the key phase in the menstrual cycle. The level of luteinizing hormone (LH) surges during this phase signalling the release of the egg from the follicle into the fallopian tube. The process is known as ovulation and the egg can then be fertilised for up to 24-48 hours. Cervical mucus is most receptive to sperm around this time and a woman has the best chances of conceiving right before and during ovulation.

It is therefore important to accurately identify when a woman is ovulating if trying for a baby, in order to maximise chances of getting pregnant. During this period When a couple has intercourse, the sperms swim through the cervical mucus, into the uterus and along the fallopian tube, where they meet the egg. While millions of sperms are released, only one sperm can fertilize an egg. If fertilization does not occur, the egg passes through the uterus, the uterine lining then breaks down and is shed several days later as the next menstrual cycle begins.

Phase 3 - The Luteal Phase

This is the final phase of the menstrual cycle and lasts from the day of ovulation to the last day before the next period. Glands in the lining of the uterus called the endometrium secrete proteins in anticipation of implantation of the fertilised egg (embryo). If implantation does not occur, the endometrium starts to break down and is eventually sloughed off leading to menstruation. The luteal phase derives its name from the follicle that produces the egg which then becomes a functioning gland called the corpus luteum. The corpus luteum produces progesterone which prepares the endometrium.

Process of conception

The human reproductive process is complex. To become pregnant, the intricate processes of ovulation and fertilization need to work just right. Every month, during a woman's menstrual cycle, a single egg is released at the time of ovulation.

The egg travels through the fallopian tube and can be fertilized within about 24 hours after its release. Conception is more likely to occur when intercourse takes place in and around ovulation.

For pregnancy to occur, a sperm must unite with the egg in the fallopian tube during this time. Sperm are capable of fertilizing the egg for many hours after deposition though they are at their functional best during the initial hours. Ideally sperm must be present in the fallopian tube at the time of ovulation for conception to occur. In order for a sperm to reach an egg, the man must have an erection and ejaculate enough semen to deliver the sperm into the vagina. There must be enough sperm, and it must be the right shape and move in the right way. In addition, the woman must have a healthy vaginal and uterine environment so that the sperm can travel to the egg.

If fertilized, the egg moves into the uterus where it attaches to the uterine lining and begins a nine-month process of growth. For some couples attempting pregnancy, something goes wrong in this complex process, resulting in infertility.

As they mature, the follicles secrete increasing amounts of estradiol, an estrogen. The estrogens initiate the formation of a new layer of endometrium in the uterus, histologically identified as the proliferative endometrium.

Problems with conception

Infertility is the inability to conceive a child. A couple may be considered infertile if, after one year of regular sexual intercourse, without contraception, the woman has not become pregnant. Primary infertility is infertility in a couple who have never had a child. Secondary infertility is failure to conceive following a previous pregnancy.

Health & fertility

Ten Steps to Fertility

Good health, nutrition and a balanced lifestyle can go a long was in improving your chances of conceiving. This 10 step approach is sure to put you on the right track to fertility.

Step One: Time is the key!

Did you know that there are only about 6 days each month when a woman might get pregnant? And the best chance is on the day of ovulation - when one of the ovaries releases a ripe egg. It is important to have sex on and around ovulation day so that the sperm makes contact with the egg and fertilization occurs.

For a woman on a regular 28-day cycle the day of ovulation will be about 14 days after the start of her period, but this can vary from person to person, so it is better to keep a diary. There are also a number of ovulation prediction kits available and you can try one of these.

Step Two: Say No to alcohol and smoking

Heavy drinking (more than six units per day) can lower a man's sperm count and affect the health of the sperm. Women are also recommended to avoid alcohol when trying to conceive as it can affect a developing foetus and cause birth defects. Smoking also harms sperm and can reduce a man's sex drive. It affects ovulation in women and can reduce fertility.

Step Three: Know your Body Mass Index (BMI)

The best indicator of health, Body Mass Index is calculated using height and weight. Find your BMI and work towards maintaining your ideal weight as it greatly impacts fertility. Excess body fat in men is also a significant cause of low sperm counts.

Step Four: Eat nutritious!

Eating a healthy, balanced diet has many advantages. It helps maintain an ideal body weight, keeps the hormone levels of the body normal and improves the health of the reproductive system. Foods that are rich in antioxidants, vitamins C and E, and certain minerals are particularly good. Vitamins C and E and Zinc play key roles in fertility, increasing sperm count and motility (movement) and reducing stress on eggs and the female reproductive organs.

Foods such as green leafy vegetables (folic acid, calcium and iron), eggs and dairy (calcium), nuts and seeds (vitamin E, zinc and selenium) and citrus fruits (vitamin C) provide the essential nutrients.

Step Five: Cut down on caffeine

Caffeine affects the fertility level of both men and women, so cutting back is a sensible precaution. Caffeine is not just found in tea and coffee but also in chocolate and some soft drinks.

Step Six: Work-out regularly

Moderate exercise every day is key to maintaining a healthy body, helping to burn off excess body fat and reducing the effect of stress on hormone levels. For men, it can boost the fertility hormone testosterone. But it is also important that women avoid excessive exercise as this can result in irregular periods. You can indulge in enjoyable, low-impact activities like walking, swimming, cycling, Pilates and yoga.

Step Seven: Avoid hard bicycle seats and hot baths

Overheated testicles can temporarily lower sperm counts in men. So men should avoid saunas, hot baths, sun bathing and tight underwear. In addition, regular and prolonged cycling on hard bike seats can also reduce fertility through pressure on the perineum - potentially damaging nerves and blood vessels to the genital area.

Step Eight: Sleep well

Good, regular sleep of about 8 hours or more per night can help both men and women optimize their fertility. Lack of sleep can have a negative effect on hormone levels, with studies of professions involving sleep deprivation (flight attendants, shift workers etc.) showing an increase in irregular periods among women.

Step Nine: Beware of other medication

Seek medical advice about other medications or herbal remedies that you are taking to see if these may affect fertility. Many over the counter medicines, and some herbal remedies such as St John's Wort, Ginkgo Biloba and Echinacea may have an adverse effect on your fertility.

Step Ten: Relax and take it easy!

Take time off now and then to relax and enjoy each other's company. Emotional stress can interefere with the hormone responsible for egg and sperm production. Consider taking regular exercise, getting home on time and taking more frequent and/ or longer holidays which can all help to reduce the pressure.

Initial workup

The first step for a couple that suspect infertilty is to determine the cause of infertility. The doctor usually begins by asking both partners about their health histories, their medication usage, their sexual histories, and their sexual practices. Tests are then performed to diagnose infertility and these tests are called pre-screening tests. Before a treatment cycle is initiated, it is important to identify any potential obstacles to achieving a pregnancy and the assessment is determined by the results of both male and female pre-screening tests.

Tests for the woman

The tests to determine occurence of infertilty in a woman begins with a full physical examination and cervical smear.

The doctor then makes sure that the woman is ovulating regularly and assesses whether her ovaries are doing their job of releasing eggs. Having regular menstrual cycles and a biphasic basal body temperature curve usually confirms that ovulation is regular. Blood tests are carried out to determine hormone levels.

The ovaries and uterus are examined by ultrasound, and tests to check for tubal blockage or any abnormality in the uterus are done.

Tests for the man

In the case of the man, to determine, the first step is a physical examination. Male infertility is usually related to sperm health or function, which is mostly tested with a spermanalysis.

In certain cases, the man may have enough sperms, but the sperms may not swim well enough to reach the egg. Also, sperms that are not normal in shape may not be able to penetrate and fertilize the egg. But once the doctor has identified all the problems, most of them are treatable.

Once the diagnosis is established for the couple, a treatment plan is drawn up. This treatment plan depends on the age, diagnosis, the duration of infertility, any previous treatments, and personal preferences if any.

In about 80% of couples, the cause of infertility is either a sperm problem, irregular or no ovulation, or blockage of the fallopian tubes. In 15% of couples all tests are normal, and the diagnosis of "unexplained infertility" is made.

Indications for ART

Male factors
  • Severe abnormalities with sperm count, sperm motility or morphology
  • Absence of sperms in the ejaculate or azoospermia
  • Mechanical or psychological issues with erection or ejaculation
Female factors
  • Older age leading to compromised oocyte quality and chromosomal abnormalities
  • Cervical factors
  • Antisperm antibodies - Can be present both in the male or female
  • Disorders of ovulation - e.g. PCOD or polycystic ovarian disease
  • Disorders of fallopian tubes - Tubal blockage either due to infections or scarring
  • Endometriosis
Unexplained infertility

In some couples all the investigations might be normal both in the male and the female and there seems to be no apparent cause for infertility. Such couples are said to be experiencing unexplained infertility though the exact reason might be at a more cellular level - pertaining to the oocyte or sperm or a combination of both. Or sometimes, there could be issues with the binding of the oocyte and the sperm.

Combination of both male and female factors.