The association between the 2D:4D ratio and offspring sex at birth: A cross-sectional study in Ghana

Early-life adversities and later-life reproductive patterns in women with fully traced reproductive history

One of the most crucial determinants of early-life development is the experience of childhood adversities. However, limited evidence is available for how these experiences shape later-life reproductive outcomes in women. Here we test the association between early-life adversities and reproductive parameters in women. Post-reproductive women (N = 105; mean age = 59.7; SD = 10.09) were recruited at the Mogielica Human Ecology Study Site in Poland within a traditional population with a low prevalence of birth control usage and fully traced reproductive histories. Reproductive parameters, as well as exposure to early-life abuse and neglect, were assessed using questionnaires. Childhood adversity was associated negatively with age at menarche (p = 0.009). Analyses on specific subtypes revealed that compared to women who did not experience any kind of early-life adversities in childhood, those who were exposed to emotional (p = 0.007) and physical (p = 0.023) neglect had an earlier age at menarche, those who experienced emotional abuse reported an earlier age at first birth (p = 0.035), and those who were exposed to physical abuse gave birth to fewer number of sons (p = 0.010). Our results suggest that women exposed to childhood adversities experience earlier physiological reproductive readiness and timing of the first birth, but their overall biological condition might be impaired as they bear fewer sons.

Sexual Dimorphism and Sex-2D : 4D Interactions on Fasting Lipid Variables in an Adult Ghanaian Population

Prenatal hormone exposure has been suggested as a correlate of adult circulating estrogen and testosterone. If this observation is true, then prenatal hormone exposure may have an association with lipid homeostasis in adulthood. The study sought to investigate sexual dimorphism and the interactions between the putative marker of prenatal hormone exposure (2D : 4D) and sex on adult fasting plasma lipid variables. The study was cross-sectional from June to December 2021 at the University for Development Studies. The participants were between 18 and 30 years of age and consisted of 206 healthy persons (female = 93, male = 113). The right hand (2D : 4DR), the left hand (2D : 4DL), and the right-left 2D : 4D difference (Dr-l) were measured using computer-assisted analysis. Fasting venous blood samples were collected and analyzed for lipid variables including total cholesterol (TCHOL) and high-density lipoprotein cholesterol (HDL-C). There were no significant differences in the 2D : 4D ratio and lipid variables between males and females. However, after adjusting for age and BMI, the 2D : 4DR (P = 0.014) and the 2D : 4DL (P = 0.007) increased with increasing fasting plasma HDL-C on average. Moreover, there were significant interactions between sex and the 2D : 4DR (P = 0.002) and also, the 2D : 4DL (P = 0.005) on fasting plasma HDL-C. The relationship between HDL-C and the 2D : 4D ratio was positive in females but negative in males. The 2D : 4DR accounted for about 54.9% and 46.0% while the 2D : 4DL accounted for about 48.2% and 14.0% of the variabilities in fasting plasma HDL-C in females and males, respectively. Prenatal hormone exposure may partly account for the sexual dimorphism in adult lipid homeostasis.