Men who want to be dads shouldn't drink ever
The party is officially over: The CDC has issued a strict edict that all sexually active, fertile women age 15 to 44 should refrain from drinking at all unless they are on birth control— whether or not they plan on having kids. The reason? It says risk of fetal alcohol syndrome to the hypothetical future child is too great, and there is no such thing as a safe amount of booze while procreating. No such warnings have been issued for men, yet research has long connected male diet, alcohol and drug consumption with birth defects.
CDC Principal Deputy Director Anne Schuchat, M.D. said of the reasoning for recommending zero booze intake in a statement, "The risk is real. Why take it?"
Oddly enough, given the glut of things pregnant women are told to do before conceiving—which range from stopping smoking, to eating folic acid, to going easy on seafood and caffeine—it's kind of incredible that there's no such directives issued to men, who typically aren't told to do anything different whatsoever prior to procreating (or after) unless for some reason the couple can't get pregnant and need fertility testing.
But the knowledge that sperm health affects the fetus is not new. In 1991, the New York Timesexplored a growing list of concerns researchers into birth defects were then detailing about how dads impact fetal health far more than previously understood. Sandra Blakeslee wrote that at the time, 250,000 children were born annually with birth defects, 60 to 80 percent of the cause of which was unknown. Today, that number has been cut in half to only 120,000 children with birth defects annually, according to the CDC. Still, the cause of some 70 percent of defects are still unknown, with physicians believing about a quarter are environmentally induced. Otherwise, causes are typically attributed to smoking, drinking, poor nutrition, hereditary diseases or sexually transmitted diseases in the mother.
That current lower birth defect rate may be, in part, because of the identification of hundreds of toxic chemicals led to "fetal protection policies" that keep women—but not men, except for lead—away from factory chemicals on the job. This oversight is in part because, Blakeslee writes, mothers and fetuses are easier to study, but also bias that led to researchers ignoring studies connecting fathers to these abnormalities. Blakeslee:
Scientists also held to what some refer to as a "macho sperm theory of conception," the idea that only the fittest sperm were hardy enough to go the distance necessary to fertilize an egg. In fact research now shows that tiny hairs in the female reproductive tract move sperm along whether they are healthy or defective.
Molecular biology has helped shed light on how damaged sperm causes birth defects, Blakeslee explains. Certain childhood cancers cause mutations in sperm, not eggs. Plus, researchers discovered that more toxic substances enter seminal fluid than they thought, because of the thin wall between blood vessels and tissue in testes. According to the Times, the main culprits in these studies are alcohol, opiates, gases in hospital operating rooms, leads, solvents, pesticides and other assorted industrial chemicals. Sometimes the studies cited showed that exposure in male mice led to reduced litters, or offspring with deformities. Or normal-seeming animals but who cannot navigate a maze. One study found that men exposed to lead at work produced male offspring with defects in brain development, even when their mothers had not been exposed.
Typically, it's thought that damaged sperm are less likely to get through to fertilize an egg, so the resulting issue is just more miscarriages or not getting pregnant at all. The problem is when the damaged sperm do get through, they might cause problems, the Times wrote.
That concern about damaged sperm getting through is still being studied. In 2010, Emily Anthes at Pacific Standard spoke with andrologist Bernard Robaire, whose career has been spent looking at the male reproductive system. He met with an oncologist at a conference in the 1980s who, after treating patients with testicular cancer, was surprised to learn they had not been rendered infertile, but were producing viable sperm, and wanted to know any risk they faced in procreating. Robaire decided to study it, but grants were hard to come by because the scientists reviewing the application thought it was an illogical question. "This makes no sense," Anthes says the scientists had written on the rejected application. "How can you expect drugs given to the male to affect the progeny?" Anthes:
It wasn't an unreasonable question. There was no obvious physiological mechanism that could explain the connection. It's the woman who makes her body home to a developing fetus, and damaged sperm were widely thought to be too weak to successfully fertilize an egg. The conventional wisdom, among oncologists, was that anti-cancer drugs would kill sperm, but after stopping treatment, sperm production would begin again — and the germ cells would be normal.
But Robaire eventually was able to study the phenomenon with a birth defects specialist, and found that the chemo damage to sperm that got through, and resulting risk to fetal development, could last as long as two years after stopping treatment (Men are now counseled to wait two years after cancer treatment to father children). "These sperm were still capable of fertilizing eggs, but the embryos would often spontaneously abort themselves," she writes. "Among those that actually survived to term, the rodent pups had abnormally slow development."
And it's not just chemo drugs, or heavy metals in manufacturing jobs that risk sperm health, Anthes says, but more innocuous substances. "Paternal smoking has also been linked to childhood cancer, and even alcohol and caffeine can cause sperm abnormalities that derail child development," she writes. Plus, only 4,000 of the some 84,000 workplace chemicals we are exposed to have been studied for reproductive effects. "There's a whole range of effects in men that really are not being given attention or are well understood," Barbara Grajewski, senior epidemiologist at the National Institute of Occupational Safety and Health, told Anthes. "The whole area of men's reproductive health is way behind women's health."
But more experts suspect that its men who pose the greater genetic risk to fetal health. "All the eggs a woman will ever have are created when she is a fetus inside her mother," Bruce Ames, Ph.D., professor of biochemistry and molecular biology at the University of California, Berkeley, told Parenting.com in 2012. But sperm cells are produced continuously, they explain. And every cell division is a chance for things to go wrong. Ames says that "fathers ultimately contribute more to the risk of gene mutations than mothers."
Looking at research across the board that links paternal health, diet, or exposure to fetal health, then, here's what fertile men between the ages of 15 and 44 should avoid:
Getting a job as a:
- Welder (toxic metal fumes)
- Fireman (toxic smoke exposure leads to heart defects)
- Power plant worker (even low levels of radiation cause higher levels of childhood leukemia in offspring)
- Mechanic or auto body worker (hydrocarbons, solvents, metals, oils, paints quadruple risk of kidney cancer in children)
Having sex if you've ever smoked a cigarette. A study from the National Cancer Institute found that fathers who had smoked at ANY POINT in their lives were 30 percent more likely to have a child with cancer.
Smoking pot. Research links marijuana use to abnormal sperm, which could lower a man's fertility.
Having sex in the summer without a condom. Sperm quality is lower during the summer.
Having sex post-treatment for testicular cancer with out a condom. The effects of chemo on sperm abnormalities are said to last up to a year.
Folate-deficient diets. In a mouse study, lack of folate in the diets of male mice contributed to birth defect in offspring, such as club feet and webbing between digits.
Having sex over the age of 35 without a condom. Men over 35 who procreate contribute to a higher risk of autism, according to Time.
Having sex after age 40 without a condom. According to that same Time piece:
The problem arises from the same 16-day turnover rate that make sperm such an infinitely renewable resource. Every batch of sperm represents an opportunity for genetic typos—called de novo mutations—to be passed on. A 20-year-old man and woman will each pass on about 20 de novo mutations to a baby they conceive. By the time the couple is 40, a woman's total has remained at 20, while a man's has jumped to 65—and it keeps climbing from there.
Other age-related risks include schizophrenia and Down syndrome.
Having sex with anyone if you have an STD, even with a condom. You can still transmit a sexually transmitted infection to your future baby mama, and infections such as syphilis, HIV, genital herpes, gonorrhea or chlamydia can cause low birth weight, blindness, deafness, bone deformities and intellectual disabilities when passed to the mother, according to the National Institute of Health.
Having sex with multiple partners, even with a condom. You could be STI-free, but pick up something from one partner and then pass it unknowingly to your future baby mama.
Gaining any weight. In another mouse study, diet-induced obesity led to changes in sperm that resulted in offspring that were more likely to be obese than offspring of non-obese mice.
Getting too excited. Even a dad's distress can mess with a baby's future mental health.
And finally, having sex without a condom anywhere the Zika virus is spreading. The possible link to microcephaly is part of the risk, but the other part is that the virus had been determined to be sexually transmitted, too.
Although governments have asked women to avoid becoming pregnant for the next two years, Christina Cauterucci at Slate asks why governments haven't asked men to abstain from sex during those same two years?
"Want to know a great way to prevent women from getting pregnant and wanting abortions because their fetuses might have microcephaly?" she writes. "Don't tell women to stop getting pregnant—tell men to stop having sex with them."
The same goes for fetal alcohol syndrome. A great way to prevent it from happening altogether is if men and women both take full responsibility for fetal health, meaning we all stop drinking and stop having sex without reliable birth control.
Come to think of it, that would probably solve most of the world's problems.