EPI-PHARE publishes the results of the study on the use of mycohpenlic acid products (MAP) among women of childbearing age and during pregnancy in France.

In total, 94,121 patients used MAP between 2010 and 2017; among them, 17,726 (19%) were women of reproductive age. The use of MAP was constantly increasing in the entire French population (+ 49% between 2010 and 2017) and among women of reproductive age (44%), reaching almost 59,000 users in 2017, including more than 10,000 women of reproductive age. Two thirds of users (67%) had a history of transplantation, of which 66% had a kidney transplant and 17% had a liver transplant. Among the patients with no history of transplant identified, nephrotic syndrome, lupus erythematosus and multiple sclerosis were the main diagnoses found (19%, 19% and 17% respectively). The increase in use of MAP between 2010 and 2017 concerned the two contexts of use (transplant: + 47%; excluding transplants: + 53%). Whatever the context of use, the MAP treatment was mainly initiated by a doctor employed by a public or private establishment. Between 2010 and 2017, 852 pregnancies occurred among women who had used MAP in the year before or during pregnancy. Of these 852 pregnancies, 410 (48%) involved transplant women and 442 (52%) women with no history of organ transplants.

The results show a significant drop in the use of MAP before pregnancy, regardless of the context of use. Among transplanted women, a relay is implemented mainly by azathioprine (in more than 70% of cases). Among women with no history of organ transplant, mycophenolate is most often replaced by azathioprine (in about a third of cases) or discontinued (in about a third of cases). A total of 383 pregnancies were identified as exposed to MAP over the study period. The annual number of exposed pregnancies remained stable at around 50 per year between 2011 and 2017. Among these exposed pregnancies, 175 (46%) occurred in transplanted women and 208 (54%) outside the context of an organ transplant. The proportion of pregnancies exposed in the context of a transplant and outside the context of a transplant remained stable over the period. The exposure period during pregnancy included the 1st trimester in the majority of cases (55%). Of these 383 exposed pregnancies, 169 (44%) had an unfavorable outcome – the most common (for 155 of these 169 pregnancies) was an abortion. Among the 214 pregnancies that resulted in a live birth, 164 newborns exposed in utero to MAP could be identified. 19 of them (12%) were diagnosed with a congenital birth defect.

In conclusion, the use of MAP has been increasing steadily since 2010 in the whole French population and among women of reproductive age, in an organ transplant context and outside. When a pregnancy occurs, a relay with azathioprine is often set up during the preconception period. However, around 400 pregnancies were exposed to MAP in France between 2010 and 2017, with serious consequences on the outcome of pregnancies and the risk of birth defects in children. Routine use of effective contraception and planning for pregnancy remains essential among women of childbearing potential using MAP.