Un new worrying finding. According to the latest study by the World Health Organization, published on April 4, one in six people in the world is infertile. “The proportion of people affected shows the need to expand access to fertility care and to ensure that this issue is no longer sidelined in health research and policy,” said its chief executive. , Tedros Adhanom Ghebreyesus. For the international health agency, it is now “a major health problem in all countries of the world”.
In poor countries as in rich countries, in the northern hemisphere as in the south, infertility affects approximately 17.5% of the adult population. The latter is defined as the inability to achieve pregnancy following at least twelve months of full, regular sexual intercourse (two to three times a week) and without contraception.
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After many years, during which the disease remained silent, hidden, shameful, tongues are loosened little by little. In February 2022, a report, bringing together around twenty gynecologists, psychologists, biologists, was submitted to Emmanuel Macron, with the aim of establishing a “national strategy to combat infertility”. If, to date, no concrete action has been taken by the government, Point returns to the main questions posed by this disease, which affects more people than asthma or diabetes.
Multiple causes, male and female
Are women more infertile than men? Responsibilities are shared, according to Inserm. In three out of four cases, infertility is of either male, female or mixed origin. This leaves 25% of couples who consult for infertility which does not present any “specific defect of one of the two sexes”. Hormonal problem, malformation, malfunction of the genital organs or environmental disturbances: several causes are possible in men as in women.
For the latter, “the first cause of infertility is the advanced age of procreation”, explains Professor Michael Grynberg, head of the reproductive medicine department at Antoine-Béclère (Hauts-de-Seine). From the age of 30, the number and quality of oocytes decrease, leading to a marked decline in fertility, which is aggravated following 37 years. However, in 60 years, the average age of first pregnancy has only increased. If in 1965, women had their first baby on average at age 24, they had 29 in 1991, 31 today, according to the latest data from INSEE.
After age come biological causes. In 20% of cases, women suffer from an ovulation problem: absence, insufficiency or alteration in the quality of oocytes, hormonal imbalance or chromosomal abnormality. Many women also have polycystic ovary syndrome. Abbreviated by the letters PCOS, this hormonal disease, due to an excessive production of androgens, in particular testosterone, the male hormone, is responsible for many cases of infertility: half of the women affected struggle to give birth, once more according to Inserm data.
Last main cause of infertility in women: mechanical problems of the reproductive system. Thus, the fallopian tubes can be blocked, preventing the transfer of the fertilized egg to the uterus. It also happens that the latter, nest for the embryo, is blocked, malformed or absent. The tissue that lines it, called the endometrium, can also show defects. In case of endometriosis, fragments are attached to other organs, making pregnancy impossible.
In men, two main causes are known and both relate to sperm. On the one hand, oligospermia which is a decrease in the number and mobility of spermatozoa. On the other hand, oligo-astheno-teratospermia (OATS) which affects more the shape of male gametes. As with women, male infertility has been on the rise in recent years. If we still lack precise data, scientists are formal: the concentration of sperm has decreased by 50% in 50 years.
Whose fault is it ? Once once more, gynecologists point to the absence of studies on the causes of infertility but agree on the certain influence of our quality of life. “Our way of life is in question, that’s for sure,” says Professor Micheline Misrahi-Abadou, head of the National Reference Laboratory for genetic infertility in women and men, at Bicêtre Hospital (Paris). But it will hardly trigger infertility on its own. Factors end up being added to it, such as endocrine disruptors, pesticides, stress…” The scientists point out that tobacco and the consumption of drugs increase the frequency of miscarriages and alter the quality of sperm. Overweight and obesity are also responsible for an increased risk of infertility. In women, it increases by 27% in case of overweight, 78% if she is obese.
Ways to fix it
Is infertility a fatality? Faced with the growing number of couples concerned, scientists are trying to find remedies to enhance fertility. In case of ovulation concerns, ovarian induction treatment is possible. Using drugs like clomiphene citrate, doctors will stimulate and induce ovulation. It should be added that in case of ovarian stimulation, the risks of multiple pregnancies and prematurity are greater.
If the couple faces infertility due to a blocked fallopian tube, endometrial tissue elsewhere than in the uterus, a dilated vein in a testicle, a uterine fibroid, a surgical operation will be offered to them by gynecologists, without guarantee for immediate success.
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In case of failure of medical and surgical remedies, it is also possible to appeal to a donation of oocytes, sperm or to benefit from IVF (in vitro fertilization) to insert into the functional female genitalia the missing gametes or embryos. Finally, let us add that, in February 2021, a first uterus transplant was carried out in France and made it possible to give birth today to two little girls.