Question:

if the father use drugs, what effect does this have on his sperm and then conseption and the fetus?

Answer:

This is an interesting question – thank you for asking.

First I must say the obvious; that relationships in general and sexual function specifically can be effected by drug and alcohol use.  Conception is less likely when relationships are adversely affected by drug use.  However, this is not the question you are asking.

In men, health and nutrition can influence the volume of sperm production and the health of the sperm.  To the extent that drugs and alcohol lead to poor nutrition, this does influence sperm numbers and quality.

Certain drugs like the opiates (heroin, Vicodin, codeine, Tylenol #3 etc,) can have an effect on sperm morphology (the sperm having a normal or abnormal anatomy) and motility (the sperm swimming normally).  These influences on sperm tend to have an “all or none” effect.  In other works, these sperm are so abnormal that women tend not to become pregnant from these affected sperm.  Women are also, therefore less likely to become pregnant if a large percentage of there sperm are abnormal.

If a woman does become pregnant, there will most probably be no effect of the drug or alcohol use on the fetus.  In other words, the abnormal sperm are not capable of causing pregnancy so there should be no effect on the fetus.  The one known class of drugs which CAN affect the fetus through the male partner is the class of drugs which causes genetic changes in the sperm – these are certain cancer therapy drugs which work through attacking the DNA of cancers.  Drugs of abuse do not cause genetic changes in sperm. 

In summary, drugs and alcohol can lead to a lower chance of pregnancy because of both social and medical effects.  However, if a woman does become pregnant and the male partner uses drugs, this will most likely not affect the developing fetus.

For more information:

Go to the Addiction and Substance Abuse health topic.