Maternal breast and body symmetry in pregnancy and offspring condition

ObjectivesFluctuating asymmetry (FA) is hypothesized to reflect the level of an individual's developmental instability, and therefore genetic quality. As a potential signal of biological condition, female body (including breast) symmetry was shown to be perceived as more attractive in mate choice context. If symmetry reflects a woman's genetic quality, it is possible that FA, similarly to other maternal anthropometric cues of biological condition (e.g., body height or waist-to-hip ratio), may be also related to her offspring condition. Materials and MethodsTo test this, breast and body asymmetry was measured in 93 pregnant women in the 1st, 2nd, and 3rd pregnancy trimester. Child's birth weight, length, chest and head circumference, information on the Apgar score, congenital malformations, and birth complications was taken from hospital records. The relationships between offspring birth characteristics and maternal breast FA and body FA were analyzed separately, controlled for a child's sex and maternal weight in pregnancy. ResultsBreast asymmetry was not a predictor of a child's neonatal condition assessed from morphological parameters at birth. Asymmetry of maternal non-ornamental body characteristcs, commonly used to assess body FA, correlated negatively with a child's weight, head and chest circumference at birth. DiscussionA composite asymmetry index of eight body traits, non-sexually selected characteristics, seems to be a better predictor of a woman's ability to invest in fetus during pregnancy than breast asymmetry, sexual ornamentation that is perceived as a signal of a woman's attractiveness and biological condition.