[LUM#9] Painkillers and pregnancy: dangerous liaisons
A study bythe Institute of Human Genetics (IGH) reveals that taking paracetamol and non-steroidal anti-inflammatory drugs during pregnancy affects the fertility of unborn children. These alarming results call for limiting the use of these drugs in pregnant women.
To relieve pain, many pregnant women continue to take paracetamol combined with a non-steroidal anti-inflammatory drug such as ibuprofen during their pregnancy. "It is estimated that 4% of women use this combination of molecules, " explains Brigitte Boizet-Bonhoure. This cocktail is sold without a prescription and is often considered harmless, but it should be prohibited for pregnant women, as confirmed by the work of theIGH biologist.
"Numerous studies have already shown that exposure to these molecules early in pregnancy increases the risk of genital malformations such as cryptorchidism or hypospadias in newborn boys, but the consequences for the development of reproductive organs and fertility in offspring were unknown," explains Brigitte Boizet-Bonhoure.
Early pregnancy: a critical period
To fill this knowledge gap, researchers administered paracetamol and ibuprofen to mice in early pregnancy. "If we draw a parallel with humans, this is equivalent to a pregnant woman taking these two drugs at the usual authorized doses between the fourth and sixth weeks of pregnancy, bearing in mind that paracetamol is authorized throughout pregnancy and that ibuprofen is only contraindicated from the sixth month onwards , " explains Brigitte Boizet-Bonhoure.
However, this very early stage of gestation is a particularly sensitive phase: it is at this point in early embryogenesis that the reproductive system develops, with the formation of embryonic ovaries or testicles. "This embryonic period determines the entire future sexual life; if there are any disturbances in these processes, there may be fertility problems in the offspring. "
And that is precisely what the researchers found. "When we analyzed adult mice that had been exposed in utero, we showed that males produce fewer sperm. " Even more worrying: when exposed animals reproduce with each other, their offspring have less motile sperm, leading to a decline in male mouse fertility from the age of 6 months, which corresponds to around 40 years in humans.
Review medication recommendations
Are there also consequences for female mice? "We are currently studying this data, but we have already observed that the fertility of females exposed in utero is also affected; in particular, they are at risk of early menopause, " explains Brigitte Boizet-Bonhoure.
Can these results obtained in mice be extrapolated to humans? "Even if we can't transpose them 100%, there is currently enough data showing that these treatments have an impact on fertility to warrant a review of drug recommendations," warns Brigitte Boizet-Bon-houre, who has shared her concerns with the French National Agency for Medicines and Health Products Safety.
These findings are particularly worrying as they show that taking paracetamol and ibuprofen affects not only rodents exposed in utero but also their offspring, who were not exposed to these drugs during gestation. "This suggests that exposure to these molecules induces intergenerational effects that could affect the genome and gene regulation of germ cells, as endocrine disruptors do, and have consequences for several generations!" says the biologist with concern. In a context where human fertility is steadily declining (see box), this is one more factor to consider in preserving reproductive health. "Pregnant women need to be warned that taking paracetamol and ibuprofen, even in the very early stages of pregnancy, is not a harmless act."
Fertility in free fall
1 in 6. That is the proportion of couples who are unable to conceive without medical assistance. It is a worrying figure, "and one that continues to rise, " warns Professor Samir Hamamah, head of the reproductive biology department at Montpellier University Hospital. According to the specialist, this decline in fertility is partly attributable to the chemicals we are exposed to every day from birth... and even long before. "The fetus is already exposed to these products in the womb, which can affect the fertility of the unborn child." Endocrine and environmental disruptors, pesticides, volatile organic compounds... in total, there are more than a hundred molecules that are toxic to reproductive health that we handle every day, often without knowing it. "When you put on lipstick, you are coating yourself with glycol ether; when you heat up a frozen meal in the microwave, you are ingesting phthalates. " These are just some of the dangerous substances hidden in even the most innocuous everyday products.
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