The magnitude of fluctuating asymmetry (FA)-an indicator of genetic and phenotypic quality-can be affected by genetic perturbations, environmental stressors, and maternal effect (maternal age, diseases, dietary deficiency). Maternal effect on human FA has been typically investigated in newborns or very young children. There are no studies investigating whether maternal effect can disrupt developmental mechanisms responsible for the secondary sexual traits that are manifested at adulthood under the influence of steroid hormones. We investigated the effect of maternal degree of obesity, gestational diabetes and hypertension, and morning sickness on the magnitude of FA in nonsexual traits as well as asymmetric thigh circumference-a sexually differentiated trait-in adult daughters. Results revealed that gestational diabetes and hypertension and maternal obesity are positively associated with FA in nonsexual traits. FA in nonsexual traits was not associated with morning sickness; however, the FA in the sexual trait (thigh circumference) was positively related to third-trimester morning sickness. Fluctuating asymmetries of nonsexual traits and thigh circumference were significantly correlated. This preliminary study demonstrates a maternal effect on adult daughters' evelopmental instability as measured by sexual and nonsexual traits. (C) 2001 Elsevier Science Inc. All rights reserved.