036. SEX SPECIFIC FUNCTION OF THE HUMAN PLACENTA: IMPLICATIONS FOR FETAL GROWTH AND SURVIVAL

Abstract

The placenta plays a central role in the development of the fetus by modulating the supply of nutrients and oxygen throughout pregnancy. We have identified that the placenta adapts to the presence of a maternal pathophysiology in a sexually dimorphic manner which results in differences in fetal growth. We have reported that the female fetus reduces her growth in response to chronic maternal asthma which ensures her survival in the presence of an acute asthma exacerbation. Conversely the male fetus continues to grow normally in the presence of maternal asthma but this is associated with a poor outcome in the presence of an acute exacerbation. We propose that the sexually dimorphic response of the fetus is derived from differences in placental adaptation to a pathophysiological condition. In the presence of a female fetus and maternal asthma, we have observed global gene changes in the placenta accompanied by significant alterations in microRNA expression. Downstream of these alterations we have observed differences in protein expression especially in relation to placental cytokines and the glucocorticoid receptor. In the presence of a male fetus there are fewer changes in global placental gene and microRNA expression, and we have observed no alterations in expression of placental cytokines or the glucocorticoid receptor. These differential adaptations ensure increased survival of the female fetus and continued growth of the male fetus in adverse conditions.