Wharton's jelly area and its association with placental morphometry and pathology

Introduction: Wharton's jelly (WJ) is the mucoid connective tissue that surrounds the vessels in the human umbilical cord and provides protection from compression and torsion in response to fetal movement. WJ is known to be altered in the presence of pregnancy complications such as gestational diabetes mellitus and preeclampsia. The present study examined associations between the cross-sectional area of WJ measured by ultrasound and postpartum placental pathology and morphometry. Methods: The area of WJ was measured by ultrasound in 156 eligible participants between 23 and 37 weeks’ gestation. Morphometric assessment of fixed cord cross sections was conducted, together with assessment of the cord and placenta for specific pathologies using standard criteria. Results: From 156 participants, 123 ultrasound images met the data quality requirements and pathology reporting was completed for 99 placentas. 17 of the participants (14%) delivered a small for gestational age neonate and 32 of the 99 placentas examined (32%) had significant placental pathology findings. Area of WJ was associated with low birth weight (p = 0.002) and was associated with specific placental pathology (p = 0.01). WJ area was positively associated with placental dimensions such as width, length and surface area. Discussion: Decreased WJ area is associated with clinically-significant placental pathology and WJ area scales proportionally with placental size. These findings suggest that WJ area correlates with functional capacity of the placenta and thus merits further evaluation alongside currently-available tests of placental function in clinical practice.