USE OF METHYLPHENIDATE IN PREGNANCY

Summary: Methylphenidate is a central nervous system stimulant used in the management of attention deficit hyperactivity disorder (ADHD). It is also used off-license in the treatment of narcolepsy.

The data regarding therapeutic use of methylphenidate do not suggest a significant increase in overall congenital malformation rates, nor do they provide convincing evidence for an increased risk of cardiac malformation as a composite outcome. Two studies which utilised an overlapping dataset have described increased risks of some specific cardiac defects (conotruncal and major arch anomalies in one and ventricular septal defects (VSD) in the other). However, the data regarding VSD risks were conflicting between the two studies, the risk estimates were imprecise, and the findings may have been produced through statistical chance.

Up to two-fold increased risks of miscarriage with methylphenidate use in early pregnancy and low Apgar score with use in later pregnancy have also been identified. Rates of intrauterine death, small for gestational age or preterm delivery have not been shown to be increased following pregnancy exposure; however, the data are too limited to exclude increased risks. As with other CNS-acting drugs, neonatal withdrawal symptoms may be expected following the use of methylphenidate during pregnancy. There are no studies on the long-term effects of antenatal methylphenidate exposure on neurodevelopment.

Growth restriction and preterm delivery have been reported following abuse of methylphenidate in pregnancy. However, the data are too limited to confirm an association and concurrent risk factors for adverse pregnancy outcomes were present in most cases.

It is important that maternal ADHD is adequately controlled during pregnancy. The risks of destabilisation and maternal relapse must be taken into account when considering dose reduction or switching a patient from methylphenidate to another medication(s).

Exposure to methylphenidate at any stage of pregnancy would not usually be regarded as medical grounds for termination of pregnancy. However, other risk factors which independently increase the risk of adverse pregnancy outcome may be present in individual cases. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.