Does Second-to-Fourth Digit Length Ratio (2D:4D) Predict Age at Menarche in Women?

Prenatal steroid levels, estimated as the ratio of second-to-fourth digit length (2D:4D), have been related to reproductive success in women, but direct associations between 2D:4D and physiological measures of fertility remain rare. A recent study reported that lower, masculinized right hand 2D:4D was correlated with delayed age at menarche in women. We addressed this question by investigating whether 2D:4D was associated with recalled age at menarche in 282 post-reproductive Finnish women, using Cox regression model that controlled for a woman's sibling composition, urban or rural residence and temporal trend in menarcheal age. We found no evidence that neither the 2D:4D of the right nor the left hand were related to a woman's age at menarche among these Finnish women. Am. J. Hum. Biol. 22:418-420, 2010. (C) 2009 Wiley-Liss, Inc.