Age affects fertility for both men and women.
As men age they:
Have less energy
Have a lower libido and are less sexually interested
Suffer prostate enlargement and erectile problems
Acquire other medical conditions like high blood pressure and diabetes that can cause erectile failure
Gain weight which can increase oestrogen and lower testosterone
The children of older men have been studies and interestingly have an increased risk of suffering from certain conditions involving spontaneous gene mutations (de novo conditions like dwarfism or achondroplasia) and are at higher risk of developing multifactorial conditions like autism and schizophrenia.
However men, as a generalisation make sperm every day of their lives and can father children into older ages.
Women are very affected by egg aging, mainly due to the fact that a woman forms all her eggs when she herself in a baby. Actually well before she has been born.
Eggs are very clever cells but very fragile. As they age, they start to make mistakes that result in incompetent embryos. A lot of the time this is because DNA divisions in the egg have occurred unevenly around the time of ovulation, IVF egg collection or fertilization. These mistakes occur both in natural conceptions and in IVF.
While miscarriages are unfortunately quite common in young women (affecting one in 5 pergnancies) in women over 40, the chance of miscarriage in 1 in 2 or 50%.
The chance of getting pregnant per month goes from 1 in 5 (20%) in younger women to 1 in 20 or 5% in a woman at 40. This statistic (the chance of getting pregnant per month) is known as monthly fecundity.
While women do have a higher chance of other problems like developing fibroids and endometriosis over time with age, the main reason for female fertility decline with age is egg quality.
However in parallel, egg quantity also declines. This make very little difference to a natural cycle when a couple is trying to conceive by having sex. However, one technology that can be used to help couples who are struggling is IVF (in Vitro Fertilisation). In IVF, a doctor calls on the ovary to give us more than it would naturally in terms of egg number. The idea is that if we can coax a woman to mature multiple eggs, each representing a chance to make a baby, then even if the majority of her eggs are no longer of high quality, we might find a little miracle amongst the crowd.
Unfortunately, some women suffer both poor egg quality and low ovarian reserve. Such women are very hard to help through IVF unless they are open to the option of using an egg donor. An egg donor is a younger women whose eggs remain healthy, who donates her egg to a woman whose own eggs are no longer capable of making babies. Sometimes this occurs in the context of early menopause but mostly not. Women generally lose their fertility around 10 years before they go through menopause – not because they have no eggs, but because the eggs they do have are no longer able to make babies.
It’s easy to think IVF can achieve more than it actually can. While IVF is a hugely powerful technology that can get around many fertility problems, we are only as good as the eggs and sperm our patients provide us with. If your eggs can no longer make babies, no amount of medication or IVF attempts can change that.
It is important as a fertility specialist to recognize when own egg treatment is futile and to gently counsel a patient down a different pathway.
Seeking fertility help at the youngest age possible is key to achieving your goals. If you are needing IVF and are over 35, speak to your fertility specialist about the number of children you ultimately desire. Consider planning stimulated IVF cycles while you are younger to bank embryos for future use. If you are single or not ready to be pregnant and over 30, research the concept of egg freezing.
Age happens to all of us. Being proactive can be a significant game changer and can be the difference in fertility treatment including IVF between success and failure.