Hum. Reprod. Advance Access published online on October 24, 2009
Human Reproduction, doi:10.1093/humrep/dep363
Digit ratios do not serve as anatomical evidence of prenatal androgen exposure in clinical phenotypes of polycystic ovary syndrome
1 Division of Nutritional Sciences, Cornell University, 216 Savage Hall, Ithaca, NY 14853, USA 2 Obstetrics, Gynecology & Reproductive Sciences, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada, S7N 0W8 3 Pathology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada, S7N 0W8
4 Correspondence address. Tel: +1-607-255-3153; Fax: +1-607-255-1033; E-mail: mel245{at}cornell.edu
BACKGROUND: Polycystic ovary syndrome (PCOS) is heterogeneous in its clinical presentation and four major phenotypes have been identified. The precise etiology of PCOS is unknown; however, variable exposure to prenatal androgens may be responsible for the spectrum of endocrine and metabolic disturbances characteristic of this syndrome. Since prenatal testosterone exposure is known to decrease the ratio of the second to fourth finger lengths (2D:4D), we characterized the left and right hand 2D:4D in women with clinical variants of PCOS. We hypothesized that if prenatal androgens were involved in the development of the phenotypic spectrum of PCOS, then lower 2D:4D would be differentially expressed among clinical variants of the syndrome.
METHODS: Digit ratios were determined in 98 women diagnosed with PCOS by the 2003 international consensus guidelines and in 51 women with regular menstrual cycles, no clinical or biochemical signs of hyperandrogenism and normal ovarian morphology. Women with PCOS were categorized into four clinical phenotypes (i.e. Frank, Non-PCO, Ovulatory and Mild) and 2D:4D among groups were compared by Tukey–Kramer multiple comparisons tests.
RESULTS: Left (P = 0.77) and right (P = 0.68) hand 2D:4D were similar among the four clinical phenotypes and no phenotype of PCOS demonstrated a 2D:4D that differed from controls (Left Hand, P = 0.44 and Right Hand, P = 0.75).
CONCLUSIONS: Women with PCOS do not demonstrate finger length patterns that are consistent with increased prenatal androgen exposure. These findings do not preclude a role for prenatal androgens in the development of PCOS; however, low 2D:4D are not a characteristic of PCOS.
Key words: digit ratios/polycystic ovary syndrome/prenatal androgen exposure
Submitted on April 28, 2009; resubmitted on August 11, 2009; accepted on August 14, 2009.