The authors point out that available evidence suggests that obesity, cigarette smoking, and consumption of alcoholic beverages are associated with diminished female fertility as measured by a longer time-to-pregnancy (TTP) among couples trying to become pregnant or undergoing assisted reproductive technologies.
They also note that while there are many studies associating stress with decreased fertility, only one other study of a population exists.
They designed a prospective longitudinal study within the ongoing Oxford Conception Study to assess the relation between salivary cortisol and a-amylase (stress hormone markers) and female fertility as measured by TTP and the day specific probability of conception during the fertile window while adjusting for purported determinants of couple fertility.
This study is nice because it planned the collection of data in advance rather than going back and getting data after the fact (much stronger scientific validity). Much of the analysis is statistical and methodologies are always subject to criticism. Nevertheless, this study provides some concrete evidence that reduction of stress helps women become pregnant.
Now, the trick is reducing the stress! As the TTP increases, my experience suggests that so does stress. Stress is quite variable because my patients exhibit a wide range of concern over their failure to become pregnant.
My recommendation to women and couples is to seek advice early so that they are informed and they make every month count toward conception. They should use whatever techniques help them relax such as exercise, acupuncture, massage, talking with friends, participation in groups such Resolve.org or the Mind-Body Program, etc.
Stress may not be the primary cause of infertility but it clearly does not help.
Buck Louis GM et. al. Stress reduces conception probabilities across the fertile window: evidence in support of relaxation. Fertil Steril 2010.
Results: Alpha-amylase but not cortisol concentrations were negatively associated with fecundity in the first cycle (fecundity odds ratio = 0.85; 95% confidence interval 0.67 – 1.09) after adjusting for the couples’ ages, intercourse frequency, and alcohol consumption. Statistically significant reductions in the probability of conception across the fertile window during the first cycle attempting pregnancy were observed for women whose salivary concentrations of a-amylase were in the upper quartiles in comparison with women in the lower quartiles.