Maternal obesity is increasingly prevalent and is associated with elevated morbidity and mortality rates in both mothers and children. At the interface between the mother and the fetus, the placenta mediates the impact of the maternal environment on fetal development. Most of the literature presents data on the effects of maternal obesity on placental functions and does not exclude potentially confounding factors such as metabolic diseases (e.g., gestational diabetes). In this context, the focus of this review mainly lies on the impact of maternal obesity (in the absence of gestational diabetes) on (i) endocrine function, (ii) morphological characteristics, (iii) nutrient exchanges and metabolism, (iv) inflammatory/immune status, (v) oxidative stress, and (vi) transcriptome. Moreover, some of those placental changes in response to maternal obesity could be supported by fetal sex. A better understanding of sex-specific placental responses to maternal obesity seems to be crucial for improving pregnancy outcomes and the health of mothers and children.

Maternal obesity is increasingly prevalent and is associated with elevated morbidity and mortality rates in both mothers and children. As the interface between the mother and fetus, the placenta has mediates the impact of the maternal environment on fetal development. Most of the literature data on the effects of maternal obesity on placental functions do not exclude potential confounding factors like metabolic diseases (e.g. gestational diabetes). Moreover, it is now clear that the placental response to maternal environment depends on the fetal sex. In this context, we reviewed how maternal obesity (in the absence of gestational diabetes) affects the human placenta in terms of (i) endocrine function, (ii) morphological characteristics, (iii) nutrient exchanges and metabolism, (iv) inflammatory/immune status, (v) oxidative stress, and (vi) transcriptome, with a focus on fetal sex specificities. A better understanding of sex-specific placental responses to maternal obesity is crucial for improving pregnancy outcomes and the health of mothers and children.