The idea that stress causes infertility is an old one. Couples struggling to conceive hear it all the time: “Just relax!” “Have a glass of wine!” “Take the pressure off by adopting a child, and you’ll get pregnant in no time!”

Today’s researchers, however, believe that psychological factors—while important—are secondary to biological ones. They know that the interaction between factors is complex. And while some studies support the idea that stress-reducing interventions boost pregnancy, the jury is still out.

The impact of stress

A 1993 study by Alice D. Domar, PhD, and co-authors reveals just how distressing infertility can be. The Journal of Psychosomatic Obstetrics and Gynecology (Vol. 14, Suppl., 45–52) article reported that infertile women’s anxiety and depression levels equaled those of women with conditions such as cancer, HIV and chronic pain.

But does infertility cause stress or does stress cause infertility? Answers to that question have shifted over time, says Annette L. Stanton, PhD, a psychiatry professor at the University of California, Los Angeles School of Medicine.

In a 2002 article in the Journal of Consulting and Clinical Psychology(Vol. 70, No. 3, 751–770), Stanton and her co-authors explain that researchers under the sway of psychoanalytic theory once believed that infertility was the result of women’s unconscious conflict. Now researchers have confirmed that biomedical causes account for most fertility problems, with psychological factors playing a much more limited role.

Jacky Boivin, PhD, a senior lecturer at the School of Psychology at Cardiff University in Wales, exemplifies that more nuanced approach. Citing converging evidence from many different areas, Boivin believes stress and fertility are related. But it’s not a simple causal relationship, she emphasizes. Stress can cause individuals to smoke or indulge in other fertility-harming habits, she says, or can cause them to drop out of fertility treatment prematurely. Highly stressed individuals may be ambivalent about having children and therefore avoid sex. And because of variation in people’s responses to stress, a population-wide relationship between stress and infertility doesn’t necessarily mean stress will impair an individual’s fertility.

That complexity—and the difficulty of researching it—makes Boivin reluctant to even say there’s a link between stress and fertility.

“The second you say to women that there’s a connection, they think ‘I’m so stressed at work, I’ve probably shut down my ovaries and will never get pregnant!’” she says. “Stress could disrupt fertility, but it very rarely—if ever—causes people never to conceive.”

While animals shut down reproductive functioning in times of scarce resources and other stresses, Boivin explains, humans have ways of overcoming that adaptive mechanism. After all, she points out, women continue to bear children during wars, famines and other situations far more extreme than anything modern Americans endure.

Psychological interventions

Can treating stress improve pregnancy rates?

Domar thinks so. In a widely cited 2000 study in Health Psychology(Vol. 19, No. 6, 568–575), Domar and her co-authors randomly assigned 184 nondepressed women to cognitive-behavioral therapy, a support group and a control group. Those in the intervention groups not only saw significant psychological improvement but also had significantly higher pregnancy rates than the control group.

“Both intervention groups had almost triple the take-home baby rate of the control,” says Domar, executive director of the Domar Center for Complementary Health Care in Waltham, Mass., and an assistant professor of obstetrics/gynecology and reproductive biology at Harvard Medical School.

However, Domar and her co-authors admit that the study had some methodological problems. For one thing, many of the participants—especially those in the control group—dropped out. Some left the study because they got pregnant, others because they needed more psychological support. These and other limitations make definitive recommendations about psychological treatment impossible, the authors note.

And not all studies are as positive as Domar’s, says Boivin. In a 2003 article in Social Science and Medicine (Vol. 57, No. 12, 2,325–2,341), Boivin reviewed the literature on psychosocial interventions for infertile patients. When it came to improving pregnancy rates, the results were mixed. Only eight of the 25 studies she analyzed examined interventions’ effects on pregnancy rates, with three showing a positive effect and five showing no effect.

What the analysis did show was that interventions—especially group interventions emphasizing education about infertility and relaxation or coping training—reduced patients’ anxiety, depression and so-called infertility-specific stress. Future studies could evaluate yoga, meditation and other such ways of achieving relaxation, adds Boivin, because what works best may vary from woman to woman.

“If people are thinking of using some kind of intervention—and you can go on the Internet and find a million things claiming they’ll get you pregnant—they should be motivated to use them to improve their quality of life rather than to increase their pregnancy rates,” says Boivin. “That’s where, chances are, it’s going to work.”

Rebecca A. Clay is a writer in Washington, D.C.