Fingerprint ridge counts, which remain constant from the 19th week of pregnancy, are related to fingertip growth during early gestation. Each finger corresponds neurologically to a spinal-cord segment ranging from C6 (thumb, relatively cephalad) to C8 (fifth finger, relatively caudad). The authors hypothesized that large ridge-count differences between fingertips (cephalad > caudad) might reflect fetal inhibition of caudal growth. Among 69 male Atlanta, Georgia, military recruits (1994-1997; aged 17-22 years), they tested associations of the anthropometric waist-to-thigh ratio with 20 ridge-count differences. Waist-to-thigh ratio was associated with the ridge-count difference between the right fourth and fifth fingertips only (dR45; r = 0.36, p = 0.003). The race-adjusted standardized regression coefficient was 0.22 (95% confidence interval: 0.03, 0.41). Since upper-body tissue distribution indicates disease risk, the authors then tested the association of age (an indicator of survivorship) with dR45 in a sample of 135 male patients from Bangalore, India (1989-1990; aged 38-82 years). Age was inversely associated with dR45 (r = -0.17, p = 0.04), notably among the 75 men with diabetes (r = -0.22, p = 0.06). An increased dR45 predicts an upper-body tissue distribution originating before the midpoint of pregnancy. The cause of this developmental pattern is unknown, but it may lead to reduced survivorship.