The role of the placenta in fetal programming of obesity

This dissertation examines the role of the placenta in fetal programming of obesity. The first paper reviews concepts of fetal programming and evaluates placental measures used to characterize the intrauterine environment. Moreover, we discuss the use of routinely collected placental measures that are not usually used in epidemiology studies. In addition, we briefly describe methods used to assess placental structural characteristics.; The second paper identifies maternal risk factors for abnormal placental growth, specifically placental growth restriction and hypertrophic placental growth. This study suggests that mothers of lower socioeconomic status are more likely to have abnormal placental growth than mothers of higher socioeconomic status. Furthermore, compared to their white counterparts, black mothers were more likely to have placental growth restriction. Finally, maternal obstetric complications are associated with either placental growth restriction or hypertrophy but not both suggesting that the compensatory response of the placenta may be specific to the disease process.; The third study seeks to identify gross placental measures as predictors of size at birth and subsequent childhood growth. Most of the placental measures were associated with birth weight and birth length. Overall, in addition to placental weight, placental measures of lateral growth were associated with z-score of body mass index at age 7 independent of their effects on birth weight.; The fourth study investigates placental histopathology as a predictor of gross placental measures, size at birth and subsequent growth in childhood. Our study shows that fetal vascular pathology is associated with diminished chorionic plate area and utero placental pathology is associated with increased in birth length. Although most of our results did not reach statistical significance, the results suggest that placental histopathology predicts diminished placental weight, thickness and chorionic plate area.; Future studies in a more contemporary cohort are needed to confirm the associations observed and further work needs to be done to improve histopathologic scales and to develop analytical approaches to summarize multiple measures of placental growth since these measures are indeed important and may give rise to the better understanding of the intrauterine environment.