Maternal obesity influences placental nutrient transport, inflammatory status and morphology in human term placenta.

CONTEXT: Maternal obesity has a significant impact on placental development. However, this impact on placenta's structure and function (i.e. nutrient transport, and hormone and cytokine production) is a controversial subject.
OBJECTIVE: We hypothesized that maternal obesity is associated with morphologic, secretory and nutrient-related changes and elevated levels of inflammation in the placenta.
DESIGN: We collected samples of placental tissue from two well-defined groups of pregnant women from 2017 to 2019. We compared the two groups regarding the placental cytokine and hormone secretion, immune cell content, morphology, and placental nutrient transporter expressions.
SETTING: Placenta were collected after caesarean section performed by experienced clinicians at CHI of Poissy-Saint-Germain-en-Laye. PATIENTS: The main inclusion criterion was an age between 27 and 37, no complications of pregnancy and a first-trimester BMI of 18-25 kg/m² for the non-obese (control) group and 30-40 kg/m² for the obese group.
RESULTS: In contrast to our starting hypothesis, we observed that maternal obesity was associated with (i) lower placental IL-6 expression and macrophage/leukocyte infiltration, (ii) lower placental expression of GLUT1 and SNAT1-2, (iii) a lower placental vessel density, and (iv) lower levels of placental leptin and hCG production.
CONCLUSION: These results suggest that placenta is a plastic organ and could optimize fetal growth. A better understanding of placental adaptation is required because these changes may partly determine the fetal outcome in cases of maternal obesity. © Endocrine Society 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.