Immunostaining of the long-form transmembrane leptin receptor in placental tissue. A, Examples of placental sections of a lean (a) and obese woman (b), and negative control (c). The long-form leptin receptor was localized to the syncytiotrophoblast (SN) and cells in the villous stroma (SC), previously identified as Hofbauer cells. B, Quantitation showed no statistical difference in the intensity of immunostaining in the syncytiotrophoblast (P = .5) and (C) villous stromal cells (0.69) by maternal body mass index (BMI). D, The expression of messenger RNA (mRNA) for the leptin receptor in the 2 extreme groups (lean and obese women) in the placental villous trophoblast showed no significant differences (P = .139). Original magnification 400× for all sections.