Meakin A, et al. - This trial ascertained the differential expression of the androgen receptor (AR), in the placenta of male and female fetuses of pregnancies complicated by asthma. Suppressed expression of some AR isoforms was disclosed in male placentae. This indicated that the common AR isoform could not be central to increased male growth. Higher AR-45 expression was reported compared to AR, in both male and female placentae of pregnancies complicated by asthma. This led to the opinion that AR-45 could exert a vital biological role in androgen responsivity. Additional analysis on placental AR isoforms could aid in comprehending the physiological mechanisms necessitating sex-specific growth differences.