# The assessment of the sexuality of patients with a borderline personality disorders based on their 2D:4D digit ratio

## TL;DR

This study explores how prenatal hormone exposure, measured by finger ratios, may influence sexual responses in women with borderline personality disorder.

## Contribution

This is the first study to link prenatal testosterone exposure, as indicated by 2D:4D digit ratio, to sexual dysfunction in women with BPD.

## Key findings

- Women with BPD had significantly lower right-hand 2D:4D ratios compared to controls, suggesting higher prenatal testosterone exposure.
- In the BPD group, lower right-hand 2D:4D ratios correlated with reduced sexual arousal and vaginal lubrication scores.
- The findings suggest a potential biological basis for sexual dysfunction in BPD related to prenatal hormone exposure.

## Abstract

The hormonal composition of amniotic fluid during prenatal development, particularly the androgen-to-estrogen ratio, may influence neuronal differentiation related to sexual response patterns and the capacity to control impulsive sexual behaviors in later life.

This study aims to assess sexual behaviors and characterize sexual responses in women with borderline personality disorder (BPD) compared to a control group.

The study included 33 women diagnosed with BPD and 56 women in a control group. BPD diagnoses were based on clinical psychiatric evaluation and the Structured Clinical Interview for DSM-IV. Elements of sexual response were measured using the Arizona Sexual Experience Scale (ASEX). The digit ratio (2D:4D) served as a biomarker for testosterone and estrogen exposure during early prenatal development.

ASEX results were analyzed in the categories of “desire,” “arousal,” and “vaginal lubrication” subscales, along with the 2D:4D digit ratio for both hands.

Lower values for the right–hand digit ratio were observed in the BPD group compared to the control group (0.989, SD = 0.034 vs. 1.016, SD = 0.039; P = 0.0014), potentially indicating higher prenatal testosterone levels. Significant correlations were found in the BPD group between the right–hand digit ratio and scores on the ASEX subscales, specifically “sexual arousal” (r = 0.406, P = 0.019) and “vaginal lubrication” (r = 0.362, P = 0.038).

These results may support biological hypotheses regarding the origins of sexual dysfunction in women with BPD.

This study is a pioneering attempt to explore the indirect impact of early amniotic hormone composition on the neurobiological conditioning of sexual response and behavior in women with BPD. Limitations include the preliminary nature of the findings, a small sample size, and results that may not be generalizable across all genders.

Physiological aspects of sexual response, such as arousal and vaginal lubrication, in women with BPD appear to be significantly correlated with prenatal testosterone levels, as indicated by the 2D:4D digit ratio.