Global population variation in placental size and structure: Evidence from Cebu, Philippines

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Julienne N. Rutherford, Victoria A. deMartelly, Haley B. Ragsdale, Josephine L. Avila, Nanette R. Lee, Christopher W. Kuzawa

2019 Placenta Vol. 85 Article Cited by 11 Quartile

Abstract

Introduction: Placental morphology influences the intrauterine environment and fetal growth, which help set life-course health trajectories across generations. Little is known about placental characteristics in populations with chronic nutritional insufficiency where birth weights tend to be lower, and how these relationships between birth and placental weights vary across populations. Methods: We collected weights and stereologically-determined villous mass and surface area of 21 placentas from offspring of women enrolled in a birth cohort study in metropolitan Cebu, Philippines, a low-income population. We identified 15 samples from other global populations ranging from low to high income that had similar data to ours to assess patterns of variation between birth and placental weights and microscopic characteristics. We ranked the population samples in order for each characteristic. Results: Mean birth weight in Cebu was 3162 ± 80 g (ranked 9/16) and placental weight was 454 ± 32 g (ranked 12/16). Birth:placental weight ratio was 7.0 (ranked 3/16). Average villous surface area for Cebu placentas was 6.5 m2 (ranked 9/12); Birth weight:villous surface area was 0.048 g/m2 (ranked 4/12). Discussion: Placentas from Cebu produced heavier neonates per units of placental weight and villous surface area than most other populations, despite lower villous surface areas and less complex surface-to-volume topography. This range of placental efficiency spurs questions about the mechanisms by which placental morphology optimizes efficiency in different environmental contexts during gestation. Placental variation both within and across populations is likely due to many intersecting environmental, metabolic, and (epi)genetic factors that will require additional research to clarify. © 2019 Elsevier Ltd

Affiliations

Department of Women, Children, and Family Health, Department of Anthropology, University of Illinois at Chicago, Chicago, IL, United States; University of Chicago, Chicago, IL, United States; Department of Anthropology, Northwestern University, Evanston, IL, United States; USC- Office of Population Studies Foundation, University of San Carlos, Cebu, Philippines; Institute for Policy Research, Northwestern University, Evanston, IL, United States