Abstract # 67:

Scheduled for Friday, June 18, 2010 03:15 PM-03:25 PM: Session 15 (Medallion Ballroom A) Oral Presentation


J. N. Rutherford1, P. Hurley2, M. S. Lawrence3 and D. E. Redmond, Jr.4
1University of Illinois at Chicago, Comparative Primate Biology Laboratory, 801 S. Paulina Street, Chicago, IL 60612, USA, 2St. Kitts Biomedical Research Foundation, 3RxGen, Inc., 4Departments of Psychiatry and Neurosurgery, Yale University School of Medicine

Fetal growth is largely mediated by placental growth and development. As fetal growth accelerates later in pregnancy, there is a shift toward greater placental efficiency. Much of the literature on placental efficiency across gestation comes from murine, ovine, and porcine models that are not fully applicable to primate fetal development and pregnancy, which are uniquely shaped by a higher degree of maternal investment, placental invasion, and fetal brain growth. A rare time series of 50 vervet monkey (Chlorocebus aethiops) fetuses and placentas from the St. Kitts Biomedical Research Foundation were examined to characterize the shift in placental efficiency across the latter half of gestation, days 83-159 of a species-typical 167-day gestation. Although both fetal mass and placental mass increased significantly with gestational age [Pearson’s Correlations: r=0.85, P<0.001; r=0.64, P<0.01, respectively], this growth was not symmetrical. Placental efficiency during period 2 [d. 131-159] was 43% greater than that of period 1 [d. 83-130] [t-test: t=-3.60, P<0.001], indicating that there is a significant reduction in the relative size of the placenta as gestation progresses in the vervet monkey. The plateau in placental growth in the vervet monkey occurs around day 130, indicating an important developmental shift in placental function. The microscopic morphology of the maternal-fetal interface of the placenta will be considered as a key mechanism in this functional shift.