Prescription and recreational drug use can have a large impact on fertility, and is responsible for a large percentage of cases where infertility has no known medical cause. Even once drug use has stopped, the effects on fertility can be permanent.
Excessive alcohol consumption can actually change your body’s hormonal balance to affect sperm production or ovulation. The effects of light to moderate consumption have not been fully studied yet, but there is a consensus that moderate drinking kills off sperm-producing cells in men and disrupts female hormones to affect fertility too.
Heavier drinking can have extreme effects on the body. In women, it can result in luteal phase defects (meaning that the uterus lining doesn’t thicken as usual to prepare for ovulation), anovulation, and amenorrhea. In men, it lowers sperm count, reduces sperm mobility, and has a large effect on sperm quality.
Research in 2003 has shown that regularly smoking marijuana can reduce sperm count and affect sperm motility. THC in marijuana can also over-stimulate sperm, which means that they slow down as they approach the egg and cannot penetrate the outer layer to complete fertilisation. If a woman has been smoking marijuana, the THC found in vaginal fluid can have the same effect on sperm.
Smoking can dramatically decrease a couple’s chances of conceiving, and has further risks during pregnancy. Men who smoke can suffer from low sperm counts and poor sperm motility, which make it harder to conceive. Female smokers can also suffer from reduced ovarian reserve and chromosomal abnormalities.
Blood Pressure Medication
Older blood pressure medications such as Largactil and Aldomet can raise prolactin levels in women (the hormones responsible for lactation) and disrupt ovulation.
Antidepressants and Antipsychotics
Some of these drugs have side effects such as loss of libido, lowered sperm count, erectile dysfunction, and menstrual irregularities. They can also affect prolactin in women and disrupt ovulation that way, or cause severe birth defects if used during pregnancy. However, serotonin reuptake inhibitors do not have the same risks attached.