A new study has found that using narcolepsy drugs such as Provigil (modafinil) and Nuvigil (armodafinil) during pregnancy may increase the risk of major congenital malformations in offspring.

The study findings were published in the Journal of the American Medical Association (JAMA) Internal Medicine.

Researchers examined nearly 150 women who used either Provigil or Nuvigil in the 6 weeks before conception or during pregnancy.

The investigators found that among the live births, around 13% had major congenital malformations, including congenital torticollis, hypospadias, and congenital heart defects. In general, the incidence of major congenital malformations in offspring is roughly 3%.

Congenital torticollis, aka wryneck, is a condition in newborns detected shortly after birth. Wryneck is characterized by a rotational deformity of the cervical spine, with tilting of the head.

Hypospadias is a “condition in which the opening of the urethra is on the underside of the penis instead of at the tip,” according to Mayo Clinic.

The researchers found that all of the newborns with congenital malformations were exposed to Provigil or Nuvigil during the first trimester of the pregnancy.

“This potential risk is not likely due to the underlying condition of narcolepsy, because previous data suggest that narcolepsy does not increase the risk of abnormal pregnancy outcomes,” the study author wrote.

They advised, “These medications should be avoided or offered along with a reliable contraceptive to individuals who could become pregnant.”

Currently, the prescribing information for Provigil and Nuvigil notes the potential for fetal harm based on animal data.

Also called smart drugs or nootropics, modafinil and armodafinil are advised to people with excessive sleepiness caused by narcolepsy, obstructive sleep apnea, or shift work sleep disorders.

Off-label, these smart drugs are used to improve concentration, focus, and attention. Many people use either Provigil or Nuvigil to perform better at their academics or workplaces. Modafinil and armodafinil are psychostimulants that have strong wakefulness-promoting effects, which is why they are recommended to people with excessive sleepiness.