Chronic psychological stress in our daily lives may change how our bodies regulate hormones, which can cause problems with ovulation, egg fertilization, implantation and other reproductive impairments. And it may have an impact on male fertility as well -- it's estimated that as many as 10 percent of infertile couples may be impacted by male sexual dysfunction (impotence) related to chronic stress [source: Seibel].
According to a recent study published in the journal Fertility and Sterility, women with high levels of cortisol (the body's stress hormone) and alpha-amylase (an enzyme circulating in our body when we're under stress) in their saliva have more difficulty conceiving than women with lower levels of the stress indicators. In fact, their fertility rate is as much as 12 percent lower each cycle [source: Louis]. Levels of epinephrine (a stress hormone you know as adrenaline) have also been found to be higher in women with unexplained fertility problems, and those elevated levels of epinephrine may constrict blood flow to the uterus [source: Bouchez].
Although there is still research to be done on what exactly it is about yoga that affects fertility, the theory is that when you reduce the body's stress response, you up your odds of getting pregnant. Consider this: A recent study found fertility patients who practice yoga specifically tailored to reduce stress may increase their fertility by as much as 35 percent [source: CBS News]. And according to data from 2000, as many as 55 percent of participants in a yoga-oriented, mind-body-based fertility program at the Benson-Henry Institute for Mind Body Medicine at Massachusetts General Hospital conceived during their first year in the program [source: Wills].
And for anyone trying to get pregnant, whether having trouble doing so or not, yoga will help melt away the emotional stress that can come along with the path to parenthood. Researchers have found that after attending just one yoga class both women and men reported they felt their mood improved. And one recent study found that people who frequently practice yoga have higher levels of a hormone called gamma-aminobutyric acid (GABA) than those who don't practice regularly (or at all) -- GABA is important in regulating mood, and when it dips too low we're at an increased risk of suffering from anxiety and depression (which in turn can increase our stress about conceiving).
For the biggest boost from your yoga practice look for classes that emphasize a gentle, restorative practice, such as Hatha or Anusara yoga styles, for example, to maximize yoga's stress-reducing benefits.