How much Benadryl can you take in pregnancy? Doctors usually recommend taking a 25mg to 50mg oral dose once every six hours [11] in the first trimester, while the dosage should not generally exceed 25mg in six hours during the last two trimesters [6, 7]. Use of topical Benadryl is considered safe in pregnancy as there is little evidence of harm to the fetus. However, there is inadequate data regarding whether the diphenhydramine in the ointment form crosses the placenta [5].
Best Answer: Mutagen: a substance that causes mutation, i.e. that causes changes in genes. Teratogen: Substance that deforms the fetus in the womb and so induces birth defects. Carcinogen: a substance that causes cancer. All of them give undesirable defects in human beings, the difference is obvious from the definitions.
A teratogen is any agent that causes abnormalities when a developing baby is exposed to it during the mother's pregnancy. These environmental exposures can cause birth defects and other problems. 1  Teratogens are can have effects that range from mild to severe, and they are often most dangerous during early pregnancy and with excessive or prolonged exposure. There are several factors that influence the severity of the effect: