ABSTRACT
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.
Subject(s)
Diabetes, Gestational , Obesity, Maternal , Male , Child , Humans , Pregnancy , Female , Placenta/metabolism , Obesity, Maternal/metabolism , Diabetes, Gestational/metabolism , Obesity/metabolism , Fetal Development/physiologyABSTRACT
Maternal obesity is associated with complications of pregnancy and increases the infant's risk of developing obesity, diabetes and cardiovascular disease later in life. The placenta has an important role in determining the pregnancy outcome, and the syncytiotrophoblast (ST) is the main component of the placenta that supports the relationship between the mother and fetus. The differentiation of the cytotrophoblast (CT) into the ST is accompanied by changes in mitochondrial functions and dynamics. The objective of the present study was to investigate the effects of maternal obesity (without gestational diabetes) on the in vitro differentiation capacities of human CT isolated from term placenta by focusing on mitochondrial status. We found that, during human CT differentiation process, maternal obesity is associated with (i) a lower progesterone secretion, (ii) a transient impairment in the ST's fusion potential (via syncytin-2 and its receptor), (iii) a lower mitochondrial content, and (iv) weaker mRNA expression of oestrogen-related receptor-gamma (a key mitobiogenesis gene). Moreover, maternal obesity altered the time course of ATP and reactive oxygen species production throughout CT differentiation. The mitochondrial dysfunctions observed in isolated human CTs of obese women might explain the observed decrease in progesterone production. Our results demonstrated that obesity in pregnancy is associated with a functional impairment of the ST which might alter the foetal-maternal dialogue.
