TUESDAY, July 13, 2004 (HealthDayNews) -- British men who served in the 1991 Persian Gulf war may suffer from a slight increase in infertility, a new study claims.
English researchers compared infertility rates between Gulf war veterans and non-veterans. Among the Gulf war vets, 2.5 percent failed to conceive within a year of returning home from the war, compared with 1.7 percent of non-veterans.
In addition, 3.4 percent of the Gulf veterans failed to have children, compared with 2.3 percent of the non-veterans, said lead researcher Noreen Maconochie, a senior lecturer in epidemiology and medical statistics from the London School of Hygiene and Tropical Medicine.
Since the infertility problems did not change over time and they occurred whether or not the men had children before the war, they may be due to permanent sperm damage caused to exposure to chemicals or toxins, Maconochie said.
The Gulf vets who did not report fertility problems also took longer to conceive, according to the study that appears in the July 14 online issue of the British Medical Journal.
Maconochie said the study can't draw a cause-and-effect relationship between service in the Gulf war and fertility problems because the research did not examine whether the men might have been exposed to chemicals that could compromise fertility.
"We can't conclude that this association is causal," Maconochie said. "We only had self-reported experience in the Gulf war. We can't really relate it to specific exposures in the Gulf war because we didn't have the data."
"Infertility is a very sensitive subject, and it is possible that some of these findings might be due to bias," Maconochie added. "Gulf veterans might have more incentive to report infertility. They might be more comfortable in telling us that they have fertility problems because they believe that their Gulf war service is responsible."
Several experts not involved with the research also said the potential for bias might undermine the conclusions.
For the study, researchers collected data on 24,379 male Gulf war veterans and a matched group of 18,439 servicemen not sent to the Gulf.
For all these men, data were available for only 10,465 veterans and 7,376 non-veterans. Among the veterans, 732 reported fertility problems, compared with 370 of the non-veterans.
In another study, the same researchers report that more than one in every 20 British soldiers who served in the 1991 Gulf war believes they have Gulf War Syndrome. The research appears in the July 12 issue of BMC Public Health.
The survey of 24,379 soldiers found Gulf war veterans were more likely to report mood swings, memory loss/lack of concentration, night sweats, general fatigue and sexual dysfunction, compared with soldiers who did not serve in the war.
Maconochie conceded she did not take into account the possible general ill health of Gulf veterans for the infertility study. "It is possible that the apparent increase risk of infertility in Gulf war veterans is due to their general ill health," she said.
Dr. Larry I. Lipshultz, a professor of urology and chief of the Division of Male Reproductive Medicine at Baylor College of Medicine, said he was "underwhelmed" by the findings.
He noted that because the response rate was so low, "selection bias" was probable. "The people who are having problems are the ones who respond," he said.
In addition, when study subjects report their own health problems, rather than have them confirmed by a doctor, a level of subjectivity can skew the research. "It's not a medical diagnosis," he said.
Also, Lipshultz noted, the difference in fertility problems between the veterans and non-veterans wasn't that great. "It's suggestive of a potential problem but not conclusive," he said.
Dr. Gabor B. Huszar, director of the Male Fertility and Sperm Physiology Laboratory at Yale University, added, "The paper reports a trend, but there are no real data in the paper which show any real difference."
Huszar believes that the numbers of men reporting infertility problems are too small to draw any meaningful conclusion.
Learn more about male infertility from the American Academy of Family Physicians.