The Difference Between Unfixed and Postfixation Placental Weight.

Journal Article (Journal Article)

OBJECTIVES: Reference values for placental weights correlated with gestational age are used in surgical pathology. Most reference values were established for fresh placentas. Some laboratories routinely fix all placentas, bringing into question the accuracy of the reference weight values. We wanted to determine the impact of fixation on placental weight. METHODS: One hundred placentas from uncomplicated pregnancies were weighed in the fresh state, after removal of the cord and membranes. After fixation in formalin for 1 day and 5 days, the placentas were reweighed. The change in weight for each placenta was analyzed by a two-tailed paired t test. RESULTS: Statistically, a small but significant gain in weight occurred after 24 hours (3.7%, P << .001), and there was no significant change identified in the additional 4 days (P = .51). Nine placentas lost weight with fixation; the weight of four was unchanged. CONCLUSIONS: We consider formalin fixation to add a statistically significant but clinically negligible amount of weight to the placenta.

Full Text

Duke Authors

Cited Authors

  • Tambouret, R; Jeck, WR; Roberts, DJ

Published Date

  • July 5, 2019

Published In

Volume / Issue

  • 152 / 2

Start / End Page

  • 217 - 220

PubMed ID

  • 31114844

Electronic International Standard Serial Number (EISSN)

  • 1943-7722

Digital Object Identifier (DOI)

  • 10.1093/ajcp/aqz033


  • eng

Conference Location

  • England