 [ Symptoms ] why is caffeine considered a drug during pregnancy [ Disease ] caffeine is legal and prevalent in foods such as chocolate and drinks such as coffee and sodas but experts claim it is still a drug and should be limited caffeine has been a controversial subject in fda guidelines in the early 1980s the fda released a study that stated caffeine use had toxic results in studies of rats however this warning has since been loosened a bit pregnant women who need caffeine should regulate their intake it can cause low birth weight and irritability if taken in large quantities