And this is another site to help answer this question. They also diminish the sperm's motility or ability to swim. Drugs can interfere with reproduction by changing the process by which sperm are selected for fertilizing the egg.
Damaged sperm can cause miscarriages .
The drugs in a man's system may lead to lower birth weight, birth defects or serious illnesses for the child after birth. A father's smoking before conception may result in lower birth weight and an increased risk of life threatening diseases such as leukemia, lymphoma, and brain cancer. The use of cocaine by men may also be linked to some mental problems in their offspring. Sperm can also be adversely effected by environmental and hazardous materials often encountered in the workplace and home. If you are starting or continuing a family see a doctor to determine if any damage has occurred.