success rates are dependant upon many factors, there are no ‘definites’.
sperm can be frozen indefinitely. there have been normal pregnancies from sperm stored frozen for 12 years. the efficacy of the freezing is questionable when it has been frozen for more than 12 years. each individual's sperm reacts differently to the freezing process.
there is absolutely no indication that insemination with thawed sperm increases the likelihood of having an abnormal or unhealthy child.