Understanding fertility and infertility
What is fertility and what are your odds of conceiving? What exactly is infertility and what causes it?
Fertility: Definition and statistics
Fertility is defined as the ability to conceive a child. It is usually at its peak in young, healthy couples, and it decreased over time.
This natural decrease is due to several factors. For example, a woman has a predefined number of ova that are released each month, usually one at a time, from puberty to menopause. The number of available ova, and therefore the woman’s fertility, gradually decreases as the woman ages. Fertility begins to decrease as of age 30, and the decrease accelerates as of the age of 35. At the same time, the risk of a miscarriage also increases with age, mainly because the quality of the ova decreases with age. Around the age of 40, there is a 40 percent risk of miscarriage. All of these factors contribute to a gradual decrease in fertility in women.
Statistically, 91 percent of 30-year-old women successfully conceive. The success rate decreases to 77 percent by the age of 35, and the 53 percent by the age of 40.
In men, fertility evolves differently. It decreases with age, but at a much slower rate than in women. As long as men have no health issues that affect their fertility, they remain fertile until an advanced age.
Fertile period
When wishing to conceive, there is another big difference to keep in mind when comparing men and women’s fertility: healthy men are always fertile, whereas women are only fertile a few days per month, at the time of ovulation.
In order to increase the odds of conceiving, it is therefore important to have sexual intercourse during the woman’s fertile period. This period varies from one woman to another and even form a cycle to another, but, usually in women with a 28-day cycle, conception can occur between day 9 and day 16 (day 1 being the first day of menstruation). Fertile period comes with physical symptoms like a temperature rise and presence of cervical mucus.
Statistically, a healthy, fertile couple having regular unprotected sexual intercourse has a 20 percent likelihood of conceiving during each cycle when the woman is under the age of 30. The likelihood drops to approximately 5 percent when the woman reaches the age of 40.
Infertility: Definition and statistics
Infertility is declared when a couple has not successfully conceived after 12 months of unprotected intercourse. Some experts take into account the duration of the attempts in relation to the woman’s age: 12 months in women aged 35 and under, and 6 months in those above the age of 35. Infertility may also be declared if a woman successfully gets pregnant but cannot carry the pregnancy to term.
The rate of infertility in Canada is approximately 16 percent (approximately one couple out of six).
Causes of infertility in women
In addition to age, the following factors may be involved when a woman is unable to conceive:
- Having an ovulatory disorder, which usually manifests as menstrual irregularity or the lack of periods
- Having had a sexually transmitted infection, chlamydia in particular
- Having uterine problems, such as fibroma or polyps
- Having a malformation of the fallopian tubes
- Suffering from endometriosis
- Having a hormonal imbalance
- Entering menopause before the age of 40
Causes of infertility in men
In men, infertility can be caused by the following factors:
- Problems with the shape or motility of the sperm
- Low (or no) sperm production
- Having had a sexually transmitted infection, chlamydia in particular
- Having a hormonal imbalance
Factors that can affect fertility in both men and women
Fertility in both women and men can be affected by treatments against cancer or certain chronic conditions (e.g. diabetes), certain types of medication, smoking, excessive alcohol intake, and being either underweight or overweight.
Does infertility occur more commonly in men or women?
When a couple is unable to conceive, the problem may stem from the man, the woman, or both partners.
Statistically, it is attributed as follows:
- A problem in the male partner in 30 percent of cases
- A problem in the female partner in 40 percent of cases
- A problem with both partners in 20 percent of cases
In 10 percent of cases, doctors are unable to find the source of the problem in either of the partners, and so the infertility remains unexplained.
Can infertility be treated?
Certain causes of infertility can be treated. For example, a malformation could be corrected through surgery, or a treatment could be prescribed for a hormonal imbalance. Some medication could stimulate ovaries to ovulate in cases where a woman has an ovulatory disorder.
When infertility is caused by a chronic illness or treatment, better management of the condition or a change in the treatment can sometimes improve fertility.
When no other causes have been identified, fertility may be increased by quitting smoking, stopping or reducing alcohol consumption, and maintaining a healthy weight. While no studies have established a direct link between stress and infertility, better stress management may help improve a couple’s quality of life as they try to conceive.
Conclusion
For myriad reasons, today’s couples are often ready to welcome a child at a more advanced age than previous generations. Since a woman’s fertility decreases over time, it is best not to delay the project too much, if possible, and to maintain a healthy lifestyle in order to improve one’s odds of conceiving. Couples who experience difficulties conceiving should not hesitate to consult a healthcare practitioner, especially if the woman is over the age of 35.