Can a father's drug use during conception cause birth defects - for example cocaine, opioids, depressants, stimulants, lsd/ecstacy?

Of course!: He does contribute 50% of the pregnancy product and genes are known to be altered by excess substance abuse. The classic case is the use of marijuana on congenital malformations.

Major drug abuse: A history of major drug abuse can cause damage to male reproductive health - but it would not be from a single use at the actual time of conception. I'd also think hard about the maturity and responsibility toward a potential child that you might expect from a man who abuses drugs enough to cause harm to his body. Creating a Life is serious business - even more than sex (which is too!) Be safe.