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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., 2010. © 2009 Wiley‐Liss, Inc.