Infertility is defined as the failure to achieve pregnancy after at least one year of systematic attempts. Since 2015 it has been described as a disease by the World Health Organization (WHO).
It concerns women (30%), men (30%), mixed causes (men and women, about 20%) and unexplained infertility, when no cause has been found after investigation of the couple (about 20% of cases).
The woman's age is one of the main prognostic factors for the outcome of an assisted reproduction treatment.
When a woman reaches 40, her chances of achieving pregnancy fall significantly, to about 5% per cycle of attempts.
For women aged 40 to 44, almost 30% are infertile, compared with only 15% of women aged 30 to 34 and 7% of women aged 20 to 25.
When women are born, the ovaries contain a fixed number of eggs available for their reproductive age.
The main cause of age-related infertility is the decline in the ovarian egg reserve. This decline is not only quantitative but also qualitative, and is expressed through genetic abnormalities in the resulting embryos. This leads not only to difficulty in achieving pregnancy but also to an increased risk of miscarriage and of giving birth to a baby with chromosomal abnormalities.
At ages 20-25 the risk of miscarriage is 10%, at 30-35 it is 12%, at 40-44 it is 35%, and over 45 the risk of miscarriage is almost 55%, according to the ASRM (American Society for Reproductive Medicine).
The number of women over 40 who have difficulty conceiving naturally and start some form of assisted reproduction treatment has increased tenfold over the last 15 years.
Before any treatment, a detailed investigation must be carried out by a specialist doctor. Both personal and family medical history should always be taken to identify any personal or hereditary conditions that could be related to infertility.
A transvaginal ultrasound is also important to rule out anatomical pathologies such as fibroids, polyps, ovarian cysts etc. In addition, hormonal testing should be performed to determine FSH, LH, oestradiol and thyroid function. Anti-Müllerian Hormone (AMH), together with ultrasound, can give us information about the ovarian egg reserve.
There are various treatment methods, and they should be individualised according to each woman's history and the cause of the infertility.
Intrauterine insemination (IUI) is a painless, non-invasive method that can be carried out in a natural cycle or with ovarian stimulation.
IVF is the most effective treatment, particularly in these age groups. Different protocols can be used. In a natural cycle a single egg is retrieved by aspiration of the follicle, under local anaesthesia or light sedation, fertilised in the laboratory and transferred into the uterine cavity, usually 3 to 5 days after fertilisation. Embryos that reach day 5 of development (blastocysts) have a greater chance of implantation.
Ovarian stimulation is more effective as we obtain a greater number of eggs/embryos. The most common protocols are the long and the short protocol with an antagonist, which requires a stimulation time of about 9-10 days. Embryo transfer at the blastocyst stage again increases the success rate.
A modern method that has been used more and more in recent years is preimplantation genetic diagnosis (PGD) of embryos to detect chromosomal abnormalities. Embryo biopsy is usually performed at the blastocyst stage, with the aim of testing and transferring euploid (chromosomally normal) embryos. This method increases the implantation success rate and reduces the miscarriage rate in older women.
Egg donation is a very effective method for women with poor egg quality, ovarian dysfunction or a history of unexplained recurrent miscarriages.
For women aged 30-35 who are not considering pregnancy for medical or social reasons, cryopreservation of eggs or ovarian tissue (fertility preservation) is an effective method that secures the storage of genetic material for use in the future.