Digit ratio (2D:4D) does not correlate with daily 17β‐estradiol and progesterone concentrations in healthy women of reproductive age

Abstract

This study shows, for the first time in a large sample of women of reproductive age, that 2D:4D is not a predictor of adult women's sex hormone concentration. The lack of relationship may be because 2D:4D might be genetically determined and is not related to maternal nutritional environment during fetal development. These results support the hypothesis that, in contrast to the nutritional quality of the fetal environment, the fetal hormonal environment (reflected by 2D:4D) does not determine reproductive physiology in later life.

Hadza hunter‐gatherer men do not have more masculine digit ratios (2D:4D)

“…Individuals of European and Middle Eastern descent for example, display higher average 2D:4D ratios compared to people of African descent (Manning et al, ). Though 2D:4D is generally correlated with fetal androgen exposure rather than adult circulating androgens (e.g., Malas et al, ; Klimek et al, ; but see Klimek et al, ), this is potentially consistent with reports that ethnic groups of African descent have 13 to 15% higher adult circulating testosterone than counterparts of European descent, after controlling for socioeconomic status and sex (Ellis and Nyborg, ). Others have similarly demonstrated that hormonal profiles vary globally as a result of environmental and energetic influences, and that these alterations in turn can have very real consequences for fertility and fecundity (Ellison et al, ; Ellison, ; Jasienska et al, ).…”

Association of primary dysmenorrhea with anthropometrical and socio‐economic factors in Polish university students

“…To the best of our knowledge, in research literature there are no works on the relationship between the digit ratio and menstrual disorders; however, the result presented in scientific literature suggest that 2D:4D digit ratio might have a life‐long connection to women's reproduction, with an impact on both duration of reproductive lifespan and, the reproductive success . It is also worth mentioning that the digit ratio is held to be strongly correlated with the hormone levels during the fetal period, although it bears no relation to sex hormone levels in adult life …”

“…42 It is also worth mentioning that the digit ratio is held to be strongly correlated with the hormone levels during the fetal period, although it bears no relation to sex hormone levels in adult life. [43][44][45][46] We may expect that the effect of sex hormones in the prenatal period, as manifested by the digit ratio, on the prevalence of dysmenorrhea is indirect. It is probably the consequence of variations in the level of abdominal obesity and age at menarche.…”

Brain sex styles: A real image for gender discrimination and response to the neurocognitive stimuli.

“…Many digit distribution ratios studies revealed that index finger (2 nd digit) and ring digit (4 th digit) is affected by prenatal androgen, thus a ratio of 2D:4D if more than 1 indicates a long index while if the ratio less than 1 indicates a short index digit, the difference in ratio of 2D:4D is sexually dimorphic more in males than females [10]. A numeral of studies has shown a correlation of 2D:4D ratios between behavioral types regarding brain sex, thus; estradiol: testosterone ratio is correlated with 2D:4D ratio, moreover, female with congenital adrenal hyperplasia has higher 2D:4D Table 6: Mean differences in psychomotor performance task and cortical arousal activity between very male brain sex and very female brain sex.…”