Int. J. Dev. Biol. 54: 237 - 255 (2010)
doi: 10.1387/ijdb.082774ll
© UPV/EHU Press

Some historical aspects of understanding placental development, structure and function

Lawrence D. Longo*,1 and Lawrence P. Reynolds2

1Center for Perinatal Biology, Departments of Physiology and Obstetrics-Gynecology, Loma Linda University, School of Medicine, Loma Linda, California and 2Center for Nutrition and Pregnancy, Department of Animal and Range Sciences, North Dakota State University, Fargo, North Dakota, USA

ABSTRACT Ideas concerning the placenta, its development, structure and function can be traced to antiquity. An issue of importance that was only resolved in the late-eighteenth to early-nineteenth century is that of the separate nature of the maternal and fetal placental circulations. Other vital issues include the placentas of twins, the structure of placental villi and their covering, the classification of placental types, the existence of the intervillous space, and the relation of maternal to fetal blood flows in the placenta. Contemporary challenges in placental biology include understanding the basic mechanisms of numerous aspects of metabolism, endocrinology, immunology, epigenetics, and the role of specific placental proteins in embryonic/fetal development.

Keywords:

placental development, placental circulation, fetus, history

*Corresponding author e-mail: llongo@llu.edu