Mycophenolic Acid (MPA) products, used as a first-line treatments for the prevention of organ transplant rejection, are also used off-label to treat autoimmune disorders.

Due to its highly teratogenic nature, MPA use is contraindicated during pregnancy in Europe. In addition, the conditions for prescribing and dispensing MPA in women of childbearing age have been reinforced in France since 2016.

The aim ot this study was to quantify and characterize exposure to MPA during pregnancy in France between 2010 and 2017, according to the pathological context of use (organ transplant or other).

The study was conducted using data of the French National Health Data System (SNDS). Any pregnancy with at least one dispensation of MPA in the 3 months prior to onset and/or during pregnancy was considered exposed. All MPA-exposed pregnancies initiated and completed between April 1, 2010 and December 31, 2017 were included. The analyses consisted in describing the MPA-exposed pregnancies (socio-demographic characteristics of the women, pathological context of use, period of exposure during pregnancy) and their outcomes.

A total of 383 pregnancies exposed to MPA were identified : 175 (46%) for whom MPA was used in an organ transplant context and 208 (54%) in another context. The annual number of exposed pregnancies was approximately 50 pregnancies per year throughout the study period. The proportion of pregnancies exposed in a transplant context and in another context remained stable. The exposure period included the first trimester of pregnancy in the majority of cases (55%). 169 (44%) exposed pregnancies had an unfavorable outcome, mainly termination of pregnancy. Of the 214 pregnancies that resulted in live births, 164 newborns exposed in utero to MPA could be identified. A congenital malformation was diagnosed at birth for 19 of them (12%).

Nearly 400 pregnancies were exposed to MPA between 2010 and 2017 in France. The consequences on pregnancy outcomes and on the risk of birth defects in children exposed in utero are damaging.