The ratio of second to fourth digit lengths: a marker of impaired fetal growth?

Background: epidemiological studies showing that impaired fetal growth has long-term adverse health consequences have depended on crude measures of fetal growth such as overall weight or length. For future studies, there is a need to develop improved morphological markers of fetal growth which persist into adult life. Recent studies have suggested that the ratio of the length of the second finger relative to the length of the fourth finger (2D:4D ratio) is determined during fetal life and may be such a marker. Aims: to determine whether the 2D:4D ratio is associated with size at birth. Design: Cohort study. Subjects: 139 men and women born in Preston, Lancashire between 1935 and 1943. Outcome measures: Measurements of the 2D:4D ratio in palm prints. Results: men who had an above average placental weight and a shorter neonatal crown-heel length had higher 2D:4D ratios in adult life. Conclusions: these preliminary findings lend support to the hypothesis that the 2D:4D ratio is determined during fetal life