Alcohol use during the teen years can not only lead to alcoholism, risky sexual behavior and early childbearing, alcohol dependence (AD) has now also been linked to delayed reproduction.

"Reproductive dysfunctions include a range of menstrual disorders, sexual dysfunctions, and pregnancy complications that include spontaneous abortion or miscarriage," explained Mary Waldron, assistant professor of psychiatry at Washington University School of Medicine and corresponding author for the study. "Teenagers who drink tend to have disruptions in their menstrual cycle as well as unplanned pregnancies."

These complications may become more pronounced with time, added Sharon C. Wilsnack, Chester Fritz Distinguished Professor in the department of clinical neuroscience at the University of North Dakota School of Medicine & Health Sciences. "Higher rates of reproductive dysfunction in adult women may reflect the cumulative effects of longer exposure to alcohol for older women than for female adolescents," she said.

For this study, Waldron and her colleagues analyzed data gathered on two groups of Australian twins born between 1893-1964 (3,634 female and 1,880 male twins) and 1964-1971 (3,381 female and 2,748 male twins). Control variables included socio-demographic characteristics, regular smoking, history of psychopathology, and family and childhood risks.

Results indicate delayed reproductive onset among alcoholic women in both groups, with little to no effect observed among men.

"To our knowledge, this is the first study to examine alcohol's effects on reproductive onset across reproductive development," said Waldron. "Most previous research has examined risks to teens or adults but not both. Our findings highlight a risk associated with AD in women that is not widely recognized – a risk that has assumed increasing importance given the increased rates of alcohol misuse by women and particularly young women."

Both Waldron and Wilsnack said the smaller effects on reproduction found among men may be due to the fact that women reach higher blood alcohol concentrations than men while consuming similar amounts of alcohol – which may contribute to a stronger link between drinking and reproductive problems in women. It may also be, added Wilsnack, that research demonstrating detrimental effects of alcohol use on male reproduction is not as extensive and consistent as research linking alcohol use to female reproductive dysfunction.

"Young women who drink alcohol may want to consider the longer-term consequences for later childbearing," cautioned Waldron. "If drinking continues or increases to levels of problem use, their ability and/or opportunity to have children may be impaired."

"For women who are already experiencing fertility problems or other reproductive difficulties," added Wilsnack, "the study's findings should warn them not to use alcohol to cope with stress caused by the reproductive problems, because alcohol would likely make the reproductive problems worse as well as carrying risks of possible alcohol abuse or dependence."

Wilsnack recommended that future research measure specific reproductive problems and their timing relative to increased drinking and symptoms of AD. This would help, she said, to clarify how much of the connection between AD and delayed reproduction is due to adverse effects of alcohol on reproductive functioning and how much is due to reproductive problems creating pain and distress that may be self-medicated by alcohol.

Results will be published in the November issue of Alcoholism: Clinical & Experimental Research.