ADHD medication methylphenidate during pregnancy not tied to malformation: Study
Denmark: The use of methylphenidate during pregnancy is not associated with an increased risk of malformations, finds a recent study in the Journal of Clinical Psychiatry.
Attention-deficit/hyperactivity disorder (ADHD) medications are being used increasingly in pregnancy. Studies on the safety of these medications are based mostly on live births which may underestimate severe teratogenic effects that may cause termination of pregnancy or fetal demise. The study by Line Kolding, department of obstetrics and gynecology, Aarhus University Hospital, Denmark, and colleagues addresses this limitation by including data from both prenatal and postnatal diagnoses of major malformations.
For the purpose, the researchers performed a nationwide registry-based study of 364,012 singleton pregnancies in Denmark from November 1, 2007, to February 1, 2014. Using redeemed prescriptions from the Danish Health Services Prescription Database, exposures to ADHD medication were obtained.
Outcome data included prenatally diagnosed malformations from the Danish Fetal Medicine Database and postnatally diagnosed malformations from the Danish National Patient Registry. The primary outcome was major malformations overall, and secondary outcomes were malformations of the central nervous system and cardiac malformations. The comparison group was pregnancies with no redeemed prescriptions for ADHD medication.
Severe cardiac malformations (SCM) were defined as concurrent diagnoses of a cardiac malformation with miscarriage, termination, stillbirth, postnatal death, or cardiac surgery within 1 year of birth.
Key findings of the study include:
- The prevalence of first-trimester exposure to ADHD medication increased during the study period from 0.05% in 2008 to 0.27% in 2013, with the majority (473/569) of the exposures being to methylphenidate.
- There were 5.1% malformations overall and 2.1% cardiac malformations among the exposed compared to 4.6% and 1.0%, respectively, among the unexposed.
- For methylphenidate, the adjusted prevalence ratios (PRs) were 1.04 for malformations overall and 1.65 for any cardiac malformations (number needed to harm [NNH] = 92), with septum defects in 10 out of 12 cases.
- The PR for ventricular septal defect was 2.74 and for SCM, 2.59.
"Methylphenidate exposure was not associated with an increased risk of malformations overall in data that included information from both prenatal and postnatal diagnoses of major malformations. There was an increased risk of cardiac malformations with NNH of 92 based on 12 cases among the exposed. More data are needed on other types of ADHD medication," wrote the authors.
"Associations Between ADHD Medication Use in Pregnancy and Severe Malformations Based on Prenatal and Postnatal Diagnoses: A Danish Registry-Based Study," is published in the Journal of Clinical Psychiatry.