Evaluation of Digit Ratios in Youth With Polycystic Ovary Syndrome

TL;DR

This study found that adolescents with PCOS have lower digit ratios, suggesting higher prenatal androgen exposure, which may predict PCOS development.

Contribution

The study provides new evidence linking lower 2D:4D digit ratios in adolescents with PCOS to prenatal androgen exposure.

Findings

PCOS adolescents had significantly lower right and left-hand 2D:4D digit ratios compared to controls.

A moderate negative correlation was found between left-hand 2D:4D ratio and mFGS in PCOS patients.

Abstract

Introduction: Polycystic ovary syndrome (PCOS) is a common syndrome often observed during adolescence, characterized by ovulatory dysfunction and hyperandrogenism. It is determined that, when female fetuses are exposed to high levels of androgens, it increases their likelihood of developing PCOS in later ages. The 2D:4D digit ratio, which measures the length of the index finger compared to the ring finger, is a precise anatomical indicator of the degree of prenatal androgen exposure. Higher digit ratios in individuals have been associated with outcomes typically attributed to females. In the adolescent age group, the relationship between PCOS and androgen exposure during the antenatal period is not clear.

Aim: The study was aimed to evaluate digit ratios in adolescents with PCOS.

Methods: The study included 38 adolescent girls with PCOS, and 40 healthy adolescent girls were selected as the control group. The digit ratio (2D:4D) was evaluated by digital calipers, and the digit ratios of the patient and control groups were compared.

Results: The mean age in the PCOS group was 15.99±1.18 years, while the control group had a mean age of 16.02±1.06 years. The right-hand 2D:4D digit ratio was significantly lower in the PCOS group (0.93±0.02) compared to the control group (1.00±0.01, p<0.001). Similarly, the left-hand 2D:4D digit ratio was also lower in the PCOS group (0.98±0.03) compared to the control group (1.00±0.01, p<0.001). There was a moderate negative correlation between the left-hand 2D:4D ratio and the modified Ferriman-Gallwey score (mFGS) (r=0.53, p=0.01). Nevertheless, there was not a significant association found between the 2D:4D ratio of the right hand and mFGS.

Conclusion: This study demonstrates that PCOS patients have significantly lower both-hand 2D:4D ratios than healthy controls, suggesting prenatal androgen exposure. Recognizing anatomic markers in adolescence may predict the development of PCOS. The findings align with previous research linking low digit ratios to androgen exposure and various reproductive outcomes.