Paris (AFP)

Children whose mothers were treated with the drug Depakine during pregnancy are five times more likely to develop developmental disorders from early childhood, a much higher level than with other epilepsy treatments, study shows French published Thursday.

The dangers for the fetus of drugs based on sodium valproate (including Depakine) have been known for many years, but while the risks of physical malformations are relatively well assessed, this is less the case with developmental disorders (autism, delay in walking, language problems ...) which they can also cause.

A team of researchers from the Health Insurance (CNAM) and the Medicines Agency (ANSM) analyzed the medical data of more than 1.7 million children born in France between 2011 and 2014 - the largest cohort studied on this subject -, and followed them until 2016, to see if they presented such disorders.

50 children, out of the 991 whose mothers had taken sodium valproate during pregnancy, were diagnosed with neuro-developmental disorders, a proportion of 5%, details the article, published in the journal Scientific Reports.

However, this proportion is only 0.89% (15,270 children) in children who have not been exposed in utero to an antiepileptic drug.

In detail, children exposed to sodium valproate during pregnancy are 5.1 times more likely to have mental retardation, 4.7 times more likely to have motor, learning or language disorders, and 4.6 times more no more autism spectrum disorders.

The proportion of children affected remains underestimated, in particular because "the limited follow-up in the study (up to the age of 3.6 years on average, and up to 5 years at most) probably led to identify only the most severe cases which give rise to an early diagnosis and / or treatment from the very first years of life, whereas less severe cases will only be identifiable with a longer follow-up period ", explains to AFP the coordinator of the study, Rosemary Dray-Spira.

- "Complementary studies" -

The article also shows that there is no increased risk in children exposed to valproate "only during the first trimester" of pregnancy, while "the available studies did not make it possible to establish whether the risk differed depending on the period of exposure, "says the researcher.

He also concludes that "the risk is lower in children exposed to lower doses of the drug than in those exposed to higher doses".

Another lesson: "the risk of early neuro-developmental disorders associated with other antiepileptics, in particular lamotrigine, appears much less marked. However, the risk (...) after exposure in utero to pregabalin", increased by 50% according to the study, "needs to be monitored and must be the subject of additional studies", underlines the epidemiologist.

"The level of knowledge" for other treatments for epilepsy has so far been "heterogeneous and generally insufficient to allow a definitive conclusion on the risk of neurodevelopmental disorders," says Rosemary Dray-Spira.

According to the recommendations of the High Authority for Health (HAS), the alternatives to valproate in epilepsy are lamotrigine (to be preferred) then levetiracetam and oxcarbazepine.

The French laboratory Sanofi, manufacturer of Depakine, is accused by families of victims of having delayed too long in informing of the risks of taking this drug during pregnancy, known since the 1980s. The pharmaceutical group was indicted this year for "manslaughter", "aggravated deception" and "unintentional injury".

The prescribing conditions of Depakine for women of childbearing age were gradually restricted from 2015 and it should now be dispensed to women of childbearing age and pregnant epilepsy patients only in the absence of therapeutic alternative (ineffectiveness or poor tolerance of other treatments).

© 2020 AFP