title: Women with more feminine digit ratio (2D:4D) have higher reproductive success.
abstract: OBJECTIVE
  Prenatal development has a long-lasting influence on biological condition and health. Second-to-fourth digit ratio (2D:4D) is suggested as an indicator of sex hormone exposure during fetal development, and it is likely that women with a more feminine digit ratio were exposed to higher prenatal estrogen levels. Therefore, we tested if 2D:4D was related to a woman's reproductive characteristics.
  
  
  METHODS
  We studied 319 women aged 46-92, who went through a natural menopause and whose husbands were alive at least until their menopause were studied. Women were recruited at the Mogielica Human Ecology Study Site located in rural Poland.
  
  
  RESULTS
  Women with more feminine 2D:4D had a higher number of children (P = 0.002), gave birth to their last child at a later age (P = 0.02), and had a longer reproductive lifespan (P = 0.04) than women with more masculine 2D:4D. Age and number of years of education were included as potential confounders in the analyses.
  
  
  CONCLUSIONS
  The results indicated that women with more feminine 2D:4D had higher reproductive success. While the exact mechanisms were not known, and the relationship between 2D:4D and adult sex hormone levels was questioned by previous studies, there might be other biological pathways explaining the observed results, that is, via behaviors that were indirectly related to fertility. Am J Phys Anthropol 160:549-553, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Environmental Health, Jagiellonian University Medical College, Grzegorzecka 20, 31-531, Krakow, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Klimek
authors.affiliation: Department of Environmental Health, Jagiellonian University Medical College, Grzegorzecka 20, 31-531, Krakow, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Galbarczyk
authors.affiliation: Department of Environmental Health, Jagiellonian University Medical College, Grzegorzecka 20, 31-531, Krakow, Poland.
authors.forename: Ilona
authors.initials: I
authors.lastname: Nenko
authors.affiliation: Department of Environmental Health, Jagiellonian University Medical College, Grzegorzecka 20, 31-531, Krakow, Poland.
authors.forename: Grazyna
authors.initials: G
authors.lastname: Jasienska
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000885:Anthropology, Physical; D005260:Female; D005385:Fingers / Q000033:anatomy & histology*; D006801:Humans; D008875:Middle Aged; D011044:Poland / Q000453:epidemiology; D055703:Reproductive Physiological Phenomena; D012424:Rural Population / Q000706:statistics & numerical data
keywords: 2D:4D digit ratio; fertility; first birth; last birth; rural population