Age & Fertility

There are a variety of different factors that can affect your fertility. From uterine abnormalities, to poor sperm count, the list of fertility problems is almost endless. This can often make it quite difficult to determine the root cause of infertility. However, age is one factor that usually comes to mind when a couple faces pregnancy difficulties. This is because age actually plays a highly significant role in determining female fertility.

It is important to remember that fertility decreases with age, particular after age 35. Even though women today are healthier and taking better care of themselves than even before, improved health in later life does not offset the natural age related decline in fertility.

Women are most fertile between age 20-24. As women grow older the likelihood of getting pregnant falls steeply while the likelihood of infertility rises sharply.

Pregnancy Rates and Age

Studies of pregnancy rates and age support the idea that female fertility declines with age. If you have not considered age as a factor in your infertility, you may be unaware of these pregnancy trends.

• Pregnancy rates begin to decline slowly, beginning in the early 30s.
• Throughout the late 30s and early 40s there is an even greater decline in pregnancy rates.
• Few pregnancies are recorded after the age of 45.
• By the age of 30, 7% of couples are infertile.
• By the age of 40, 33% of couples are infertile.

Factors Involved in Female Fertility Loss

Menstrual cycle: irregularity in menstrual cycle is common with increasing age.

Lining of the womb: The endometrium may become thinner and less hospitable to an embryo

Mucus secretion: vaginal secretions can become less fluid.

Diseases affecting the reproductive system – some conditions can damage the reproductive organs as time passes or worsen if not treated properly, including endometriosis, PCOS and Chlamydia.

Chronic illness – some illness can have a negative impact on fertility.  

Egg Quantity as You Age
As you age, the number of eggs in your ovaries begins to decrease. By the time you begin menstruating you have only about 400,000 eggs available for fertilization. Each month you may produce several eggs for ovulation, but many will die before they are ever fertilized. By the time menopause arrives, most women only have a few hundred eggs left in their ovaries. Because the number of eggs that you have available for fertilization declines with age, this can make it more difficult to become pregnant as you grow older.
Egg Quality as You Age
Unfortunately, egg quality also changes over time. As you age, your eggs become weaker, and less able to form a healthy embryo. Your eggs also begin to decrease in number, leaving fewer and fewer quality eggs available for fertilization. A woman of 40 typically has lower egg quality than a woman of 20.This is not to say that your eggs are of poor quality just because you're aging. Many younger women have poor quality eggs while some older women have very high quality eggs. On average however, egg quality does decline with age.
Complications of Poor Egg Quality
Poor egg quality can lead to a variety of complications, including:

• unexplained infertility
• IVF or IUI failure
• repeated miscarriages
• chromosomal abnormalities

How long will it take to conceive? 

According to the Human Fertilisation and Embryology Authority, "At 35 you're half as fertile as when you were at 25; at 40 you're half as fertile as when you were 35". This means that it can suddenly take much longer to get pregnant when you hit your late thirties or early forties and you may have problems conceiving at all.

Most couples (92 per cent) will conceive within two years if they do not use contraception and have regular sex. That leaves 8 per cent of couples in the general population who do not conceive within two years. If you are over 35 and keep on trying for another year you may still get pregnant but in the next few years your chances of conceiving start to fall rapidly; 6 per cent of women aged 35 years and 23 per cent of those aged 38 years will not have conceived after three years of regular unprotected sex.

Getting Pregnant After Age 30

Statistically speaking, the chances of pregnancy for women over 30 start to decline by about 3.5% per year. This rate continues to increase after the age of 40. After 45, however, experts say it is virtually impossible for a woman to conceive using exclusively her own eggs.

That’s why women over the age of 35 will generally undergo a fertility evaluation if they do not conceive after 6 months of having unprotected sex.

In summary, age and infertility is an increasing problem due to general societal trends for women to delay childbearing until later ages. Despite these grim statistics, not everyone will have trouble getting pregnant after 35. However, if you are having trouble, and you’re older than 35, you shouldn't try on your own for longer than six months. The sooner you get help, the better your chances of treatment success.