Observational Study of the Social Determinants of Health in Subfertile versus Nonsubfertile Women

CONTEXT: Subfertility affects about 15% of couples worldwide. There are several factors that affect subfertility called social determinants of health (SDH): biological factors as age, ethnic origin, and body mass index; behavioral factors as alcohol intake, smoking, coffee, dietary restriction, physical activity, and psychological state; and contextual factors as education, work activity, and income level. AIMS: The aim of the study is to evaluate the distribution's relevance of the SDH in subfertile women versus nonsubfertile women. SETTINGS AND DESIGN: A prospective comparative study with two groups of women recruited over 1 year at hospital consultation: one group with subfertile women excluding women without a male partner or with a previous child and another one formed by primigravidae, excluding those receiving assisted reproduction techniques to become pregnant. SUBJECTS AND METHODS: We compare the different factors between subfertile and nonsubfertile women one by one. Second, a multivariate analysis was conducted with logistic regression. In all cases, informed consent was obtained. RESULTS: Regular physical exercise 3–4 times/week (odds ratio [OR]: 0.33, 95% confidence interval [CI]: 0.15–0.71) or healthy food products such as fish 1–2 times/week (OR: 0.40, 95% CI: 0.17–0.95) were associated with nonsubfertile women. CONCLUSIONS: The distribution of SDH in natural fertility is not altogether homogeneous. Weight control by means of restricting calorie intake, greater consumption of healthy foods such as fish, regular physical exercise, and lower age are positively associated with fertility. Population-level intervention is possible to improve women's health, as these are modifiable factors. Ethnic origin can be considered as a relevant factor, as it may condition the distribution of other determinants.