The placenta is a unique organ, made up of cells with 2 similar yet distinct genetic makeup, maternal and fetal. Further, a placenta can be either a female or a male placenta, corresponding to the sex of the fetus. Understanding the role of sexual dimorphism of the placenta in terms of its development, maturation, function and basic physiology is needed but sorely lacking. Such insights will provide the grounding for evaluating if fetal and therefore, placental sex, acts as a modifier of the insults in utero faced by the placenta, leading to adverse birth outcomes with a prima facie case of placental dysfunction.
Our group has reported multiple instances of fetal-sex specific dysregulation of key placental genes within the context of fetoplacental growth and small-for-gestational age (SGA) births. We believe that this is just the tip of the iceberg, in appreciating the role of sexual dimorphism in placental pathophysiology. In-depth investigations in this area will not just improve our undestanding of the way the placenta adapts to support differing growth trajectories of female versus male babies in utero, it will also lead to identification of effective and focused placenta-based clinical biomarkers for adverse birth outcomes, including but not limited to fetal growth restriction.