Association Between 2D/4D Digit Ratio and Age at Menarche: A Study on the Algerian Population

The ratio between the length of second and fourth digits (2D/4D) is a putative biomarker for prenatal testosterone and estrogen exposure.

The aim of the present study was to examine the association between 2D/4D digit ratio and age at menarche in Algerian women.

The study included 111 women with mean age of 26.49 ± 8.30 years. The 2D/4D was measured directly in both hands using a digital caliper. Multiple linear regression and Mann-Whitney U-tests were used to assess the associations between the digit ratio and the variables studied.

A total of 111 women reported a mean age at menarche of 12.89 years ±1.25. The left-hand digit ratio was negatively related to age at menarche. Statistical analyses revealed a significant negative correlation between the left-hand 2D/4D ratio and age at menarche, suggesting that a more feminine digit ratio is associated with an earlier age at menarche.

These findings support the evidence for the role of prenatal hormonal influence on reproductive development and contribute to the growing interest in research on digit ratio and female reproductive health. Further studies are needed to confirm these associations in different populations.