Entecavir is a class of antiviral drugs that are mainly used in clinical practice for the treatment of viral hepatitis. Before the drug is marketed routinely need to do reproductive toxicity, genotoxicity, pharmacological toxicity and other aspects of the test, entecavir is no exception, in the market before the study done on rats, rabbits, etc., given to humans orally tens of times the standard dose, or even hundreds of times the drug, rats and rabbits did not find obvious genotoxicity and abnormalities, chromosomal mutations and other phenomena, proving that entecavir should have no effect on fertility. Of course, this is only an animal experiment, because humans are forbidden to experiment with these drugs, so for the sake of eugenics, if it is allowed, it is better to stop the drug before having children, and if you happen to get pregnant during the drug, there is no need to panic, there should be no obvious effect on the offspring.