Association of the Mediterranean Diet With Fertility Outcomes
Condition: Infertility
MeSH terms: Infertility
Study type: Observational

Summary: 
      Infertility affects one of every six couples and one out of ten couples may seek fertility
      treatment such as ovulation induction and assisted reproductive technologies. With respect to
      diet, several dietary factors, i.e. micro-, macro-nutrients and individual food groups, have
      been associated with the risk of subfertility; however, more information is needed on the
      role of dietary factors in reproductive functions. However, evidence concerning the
      association between dietary patterns, such as the Mediterranean diet (MD) pattern, and
      fertility is scarce. The aim of this study is to investigate the relationship between
      preconception dietary patterns, especially the MD pattern, and in vitro fertilization (IVF)
      outcomes, as well as adiponectin and follistatin concentrations in the plasma and follicular
      fluid of women undergoing IVF treatment. Blood and follicular fluid adiponectin and
      follistatin concentrations will be measured on each day of the ovarian stimulation protocol.
      Main IVF treatment outcomes are fertilization rate, oocyte and embryo quality, implantation,
      clinical pregnancy and live birth rates.
    

Detailed description: 
      Infertility affects one of every six couples and one out of ten couples may seek fertility
      treatment such as ovulation induction and assisted reproductive technologies. There are
      multiple causes of infertility, including ovulatory disorders, endometriosis and sperm
      factors, or even psychological problems, among others. Modifiable lifestyle factors, such as
      diet, smoking and physical activity, may also affect fertility. With respect to diet, several
      dietary factors, i.e. micro-, macro-nutrients and individual food groups, have been
      associated with the risk of subfertility; however, more information is needed on the role of
      dietary factors in reproductive functions. A more comprehensive approach to investigate the
      associations between dietary factors and health outcomes is to assess the impact of the
      overall diet rather than separate foods or nutrients. However, evidence concerning the
      association between dietary patterns, such as the Mediterranean diet (MD) pattern, and
      fertility is scarce. The benefits of the MD on health have been well-publicized; it is
      associated with a significant reduction of overall mortality, cardiovascular disease and
      cancer. Adherence to the MD also seems to reduce the risk of weight gain and diabetes,
      conditions that raise insulin resistance and may thus lead to ovulatory infertility.
      Recently, adherence to MD was also associated with an increase in circulating adiponectin
      levels, a hormone produced by the adipose tissue that acts to reduce insulin resistance.
      Interestingly, adiponectin has been shown to exert actions in the female reproductive system,
      including the hypothalamic-pituitary ovarian axis and endometrium, and thus, it can be
      hypothesized that MD may exert a beneficial effect on reproductive functions through a
      raising effect on adiponectin levels. The aim of this study is to investigate the
      relationship between preconception dietary patterns, especially the MD pattern, and in vitro
      fertilization (IVF) outcomes, as well as adiponectin and follistatin concentrations in the
      plasma and follicular fluid of women undergoing IVF treatment.

      Two-hundred subfertile couples undergoing IVF treatment at a Fertility Clinic in Athens
      (www.embryogenesis.gr/) will be invited to participate. Participants will fill out the
      following questionnaires: a general questionnaire to record the baseline characteristics of
      the subjects (age, educational level, annual income, medical history, body mass index,
      smoking, etc), a semi-quantitative 77-item food frequency questionnaire to assess habitual
      dietary intakes, and a 40-item state-trait anxiety inventory instrument to measure anxiety
      symptoms. Dietary patterns will be evaluated using principal component analysis and factor
      analysis. Adherence to the MD will be assessed with a MD-score that incorporates the inherent
      characteristics of this traditional diet, that is, high intake of plant foods and olive oil,
      low intake of meat and dairy products, and moderate intake of alcohol. Blood and follicular
      fluid adiponectin and follistatin concentrations will be measured on each day of the ovarian
      stimulation protocol. Main IVF treatment outcomes are fertilization rate, embryo quality,
      implantation, clinical pregnancy and live birth.

      Associations between dietary patterns, adiponectin and follistatin concentrations and the IVF
      treatment outcomes will be tested using linear and logistic regression analyses, adjusting
      for potential confounders (e.g. age, smoking, anxiety symptoms, etc). The findings of the
      study could contribute in the development of guidelines to prevent infertility or to
      nutritional management associated to infertility treatments to improve reproductive
      performance. Furthermore, the elucidation of the role of adiponectin and follistatin in
      female reproductive functions and its association with dietary variables and the IVF outcomes
      could lead to the use of adiponectin or follistatin as therapeutic targets in novel treatment
      strategies of infertility disorders.
    

Intervention name(s): Lifestyle behaviour and dietary habits assessment
Intervention type(s): Other
Intervention description(s): Lifestyle behaviour and dietary habits assessment
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Subfertile couples undergoing IVF treatment at a Fertility Clinic in Athens
      
Biospecimen description: 
      Blood, follicular fluid
    
Keywords: Fertility; Infertility; Dietary Patterns; Mediterranean diet; Adiponectin; Follistatin; Assisted Reproduction; In Vitro Fertilization; Semen quality; Diet; IVF