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| Illustrations by Rod Clement |
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There is a growing problem of 'sick sperm'.
Medical evidence is rapidly accumulating that a man's exposure to a variety of substances before they father a child can seriously damage the health of their unborn baby. It would seem that gone are the days when only a mother is the target of heartless blame should a birth defect occur.
Pregnant women are rightly cautioned to avoid alcohol, tobacco, certain other drugs, work place chemicals, radiation, and a variety of other substances. But it now seems that men too should also guard against dangerous exposures prior to conception.
Medical researchers now suspect that many birth defects come from damage to the sperm of men exposed to various teratogens. A teratogen is any substance which produces a birth defect. Simply put, the teratogen makes the sperm unwell--unfit for the task of helping to produce a healthy, defect-free baby.
According to Dr. Donald Mattison, 'that the man's contribution to birth defects has been ignored for several decades is astonishing. Many medical students are still taught that spontaneous abortions are caused by sick eggs. Sick sperm are never mentioned.' Dr. Mattison is the Dean of the Graduate School of Public Health at the University of Pittsburgh and Chairman of the Board of Health Promotion and Disease Prevention of the National Academy of Sciences/Institute of Medicine.
About 70 per cent of birth defects still defy scientific explanation. Several years ago, this realization stimulated medical science to look for additional sources of causative factors. In addition, one surprising study revealed that a number of rare childhood cancers stem from mutations in sperm more often than from mutations in eggs. Thus, according to Dr. Devra Davis, science finally recognized what everyone else knew: 'That reproduction is a two-person process'. Dr. Davis is a University of Pittsburgh colleague of Dr. Mattison, consultant to the World Health Organization, and the author of WHEN SMOKE RAN LIKE WATER (2002) - a book about environmental dangers and human health. Dr. Davis adds that 'since sperm cells divide rapidly, they have many opportunities to mutate'. Furthermore, 'toxins probably reach sperm cells faster than they reach eggs cells. So sperm may be even more susceptible to substance-based damage than eggs.'
Although there is no direct cause-effect relationship between a father's exposure and a baby's birth defect, certain correlations have been discovered over the last two decades or so.
- Men who smoke cigarettes before their children are born are 40 per cent more likely than non-smoking men to have children who develop leukemia. Moreover, they are 60 per cent more likely to produce children who develop lymphomas or brain cancers.
- Men who have two or more alcoholic drinks daily during the month before they conceive children are more likely to produce babies with significantly lower birth weight. Birth weight is generally taken to be a major indicator of over-all infant health.
- In a controversial study by the Harvard University School of Public Health in 1990, men who served in the Vietnam War were shown to be up to 70 per cent more likely than other men to father children with major malformations. These defects included damage to the infant's central nervous system, genital organs, urinary tract, and cardiovascular system. One of the reasons that the study remains controversial is that Agent Orange was implicated.
- Equally controversial, men who served in the Gulf War in the early 1990s were at increased risk of fathering children with birth defects. Probably the largest study of this kind was a report by the U.S. General Accounting Office in 1994 that identified 21 potential toxicants and teratogens present during the Gulf War and listed agents that were present in smoke from oil fires, soil samples, pesticides, and decontaminating agents. In addition, a high proportion of deployed personnel were exposed to multiple vaccinations including those for plague and anthrax, while some also took pyridostigmine bromide (anti-chemical warfare nerve agent preventative or NAPS) tablets.
- A 2003 British study from the London School of Hygiene and Tropical Medicine suggested that birth defects could occur to children of soldiers exposed to Middle East war conditions.
- Men exposed to low levels of radiation at the nuclear power plant near Sellafield, England were found to have fathered children with a six times greater risk of developing leukemia or non-Hodgkin's lymphoma.
- Men who work at jobs that routinely expose them to paints were found to be seven times more likely to father children who develop brain cancers by the time the child is ten years old.
- Men exposed to chemical solvents as a regular part of their work are nearly three times as likely to father children with brain tumors.
- Men who work in the glass, clay, stone, textile, or mining industries have twice the average risk of fathering premature infants. Premature birth is also an indicator of over-all infant health.
- Men exposed to vinyl chloride, a common ingredient in plastic and water-treatment products, have wives who experience elevated miscarriage rates. Often, when a serious fetal malformation occurs, the pregnancy is terminated through a spontaneous abortion or miscarriage.
- Men who work as firemen, and thus are exposed to the vast number of poisonous fumes in smoke, have increased risk of fathering children with cardiac defects.
- Men who work in the aerospace industry produce children with higher rates of brain tumors.
- Men whose jobs expose them to electromagnetic fields are perhaps twice as likely as others to father babies who develop neuroblastomas. These are cancers of the nervous system. Electricians, power company linemen, and welders are included here, among others.
According to Dr. Mattison, 'there are no clear answers to these worries. Compared with the past, we live pretty healthy lives and these are things we are not very certain about. We don't know the magnitude of the danger. But people can take steps to protect themselves.'
The trick to make sick sperm well is to never make them sick in the first place.
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A Brisbane, Australia fertility clinic was set up 20 years ago by several doctors, including obstetrician and gynaecologist, Dr. Warren D'Ambrosis. In the mid-1980s, male sperm was identified as the major cause of a couple's infertility in 20% of cases. Now, problem sperm is involved in 50 per cent of cases and the numbers of couples seeking help has increased tenfold.
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In a condition called Sertoli Cell-Only Syndrome, a man's body produces no sperm at all. Scientists are still speculating about the genetic causes for the syndrome and also how chemicals and toxins might play a role. It's thought though that this syndrome can be associated with deletions of genes from the male Y chromosome.
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