Drug Exposures in the Male Partner and teratogenecity
How does the exposure to teratogenic drugs in male partner affect fetus?
@zain Research is increasingly addressing the role of paternal exposure to medications before conception or during his partner’s pregnancy. Certain exposures may alter the size, shape, performance, and production of sperm. This observation suggests that drug exposure in the male may put the fetus at risk. Animal studies have shown that paternal teratogenic exposure may lead to pregnancy loss or failure of the embryo to develop. However, unlike teratogenic agents taken by pregnant woman, teratogenic agents affecting the father do not seem to directly interfere with normal fetal development. Animal studies show that paternal teratogenic exposure may lead to pregnancy loss or embryonic failure.
At present, no evidence shows that paternal exposure directly increases the risk of birth defects. A large cohort of over 340,000 pregnancies in Norway did not find paternal drug exposure to be a particularly important cause of birth defects or adverse pregnancy outcomes, especially after controlling for confounding factors with maternal exposure. Agents such as recreational drugs do affect sperm quality and, to a limited degree, indirectly expose the developing fetus to the substance. Rather than affecting the developing fetus, teratogen exposures like illicit drugs and alcohol seem to lower the likelihood of a woman's becoming pregnant rather than resulting in adverse pregnancy outcomes.
Paternal alcohol use may increase the risk of heart defects in newborns. In one study, paternal smoking was associated with heart defects. Chemotherapy or radiation therapy to treat cancer in a father may increase the risk chromosomal abnormalities of the fetus. Studies have demonstrated less-than-normal numbers of chromosomes and damage to the structure of chromosomes in the sperm of men with cancer. No data suggests an increased rate of birth defects in fetuses conceived with sperm from male chemotherapy patients.
Paternal exposure to prescription medications, such as cholesterol- and blood pressure–lowering drugs, has not been linked to a risk of birth defects. Additional research must clearly be conducted to assess the safety of drugs recently released onto the market. Regardless of the lack of evidence supporting a direct influence of paternal exposure on fetal risk, caution is warranted, and the father's physician should provide counseling and active involve the patient.