Understanding the basic components of fertility allows us to home in on each aspect to optimise it for better fertility and natural conception. This should be done in conjunction with a broader view of overall general health, as explained later. Essentially, becoming pregnant can be broken down into three components: the quality of the egg and sperm, the sperm’s journey to the egg and the receptibility of the uterus lining.

Follicles (eggs)

At birth, a woman will have between 500,000 and 1,000,000 follicles (each containing an egg). Incredibly, with a woman ovulating just once a month from puberty to menopause, fewer than 500 of the 500,000–1,000,000 eggs will reach ovulation. During each menstrual cycle, around 10–20 follicles are stimulated at once with generally just one becoming dominant and ovulating. This number declines rapidly by the age of 38, with around 25,000 remaining in the ovaries, and then decreasing ever more rapidly until about 1000 remain around the age of menopause, normally around the age of 49.

Follicles are dependent upon good amounts of anti-Müllerian hormone (AMH) and androgens (testosterone, androstenedione and sex hormone-binding globulin (SHBG)). The follicle converts androgens into oestrogens, which helps it grow. The follicles also need good amounts of protein and complex carbohydrates to grow. It takes 85 days for the egg to grow from start to finish.

Sperm

The volume of semen in a typical ejaculation is 2.5-5mL, with 50-150 million sperm per mL, giving an average normal sperm count of 125-750 million. When trying for a baby, having sexual intercourse just around the time of ovulation sends billions of sperm on the hunt for one egg! However, only 1 per cent of sperm will reach the cervix and only around 0.01 per cent from each ejaculation will reach the ovary.

The volume of semen in a typical ejaculation is 2.5-5mL, with 50-150 million sperm per mL, giving an average normal sperm count of 125-750 million. When trying for a baby, having sexual intercourse just around the time of ovulation sends billions of sperm on the hunt for one egg! However, only 1 per cent of sperm will reach the cervix and only around 0.01 per cent from each ejaculation will reach the ovary.

Sperm health has been plummeting since 1938. This is mainly caused by exposure to chemicals, excessive stress and poor lifestyle and diet choices. Making simple changes to a man’s diet and lifestyle can have a massive positive impact upon his sperm quality.

Because the sperm need to travel a vast distance they must be strong and mobile. This journey from the vaginal canal up into the fallopian tube where insemination takes place helps to eliminate the weak from the strong and gives a higher probability that sperm with intact DNA in their head are able to reach the egg and penetrate it. However, the DNA within a mature sperm head can still have chromosome abnormalities. It’s therefore important to try to improve sperm quality as much as possible.

To learn more about the egg and sperm and how to improve them, read My Fertility Guide.