Objectives: The purpose of this study was to examine the potential for 3-dimensional sonographic measurement of the early placenta in predicting ultimate placental morphologic features at delivery.
Methods: In this prospective cohort study, we collected 3-dimensional sonographic volume sets of placentas at 11 to 14 weeks and then collected the placentas after delivery. The sonographic data were manipulated to obtain various novel measurements of early gross placental morphologic features and the umbilical cord insertion location. The placental weight, chorionic plate area, cord location, and mean chorionic vascular density were obtained from the delivered postpartum placentas. Analyses were performed to identify potential early placental characteristics that were correlated with the ultimate placental morphologic features. The placental weight, cord marginality, and mean chorionic vascular density served as the outcome measures of interest.
Results: Measurements of the early placental volume correlated with the delivered placental weight. An irregular early placental shape, as measured by sonography, was significantly inversely correlated with placental weight (P < .05). The placental morphologic index, a measure of a flatter placenta, was inversely correlated with both the placental weight and chorionic plate area, possibly indicating the importance of placental thickness even in the first trimester before villous arborization. In addition, early sonographic measures of the location of the umbilical cord insertion were significantly correlated with the ultimate marginality of the cord insertion as well as the mean chorionic vascular density (P < .05).
Conclusions: Many important ultimate placental morphologic features are likely predetermined early in pregnancy. Three-dimensional sonography may play an increasing role in the in utero evaluation of the early placenta.