The Association between Disproportionate Birth Weight to Placental Weight Ratio, Clinical Outcome, and Placental Histopathological Lesions.
BACKGROUND
High and low birth weight (BW) to placental weight (PW) ratios (BW/PW) have been proposed as markers of placental malfunction. We studied the association of clinical outcome and placental histopathology lesions with BW/PW ratios.


METHODS
During the period between 2008 and 2013, placentas from deliveries at gestational age (GA) ≥37 weeks, including both complicated and uncomplicated pregnancies, were sent for histopathology evaluation. Maternal and labor characteristics and pathological reports of the high BW/PW ratio group (>90th), normal BW/PW ratio group (10-90), and low BW/PW ratio group were compared (<10th).


RESULTS
The BW/PW ratio increased as GA increased, with an average GA of 39.4 ± 1.2 weeks in the normal BW/PW ratio group (p < 0.001). Patients with diabetes mellitus and smokers were more common in the low BW/PW ratio group (p < 0.001). Placental maternal stromal vascular lesions and villitis of unknown etiology (VUE) were more common in the high BW/PW ratio group (p < 0.001 and p = 0.03, respectively). By logistic regression analysis, GA, placental maternal stromal vascular lesions, and VUE were found to be independently associated with a high BW/PW ratio, while diabetes mellitus and smoking were independently associated with a low BW/PW ratio.


CONCLUSIONS
The BW/PW ratio increases significantly beyond 39th weeks, and is associated with an increased rate of placental maternal stromal vascular lesions and VUE.
Department of Obstetrics and Gynecology, Edith Wolfson Medical Center, Holon, affiliated with Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Hadas
H
Ganer Herman
Hadas
H
Miremberg
Letizia
L
Schreiber
Jacob
J
Bar
Michal
M
Kovo
D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D016015:Logistic Models; D010920:Placenta / Q000033:anatomy & histology* / Q000502:physiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis / Q000473:pathology; D011256:Pregnancy Outcome; D012189:Retrospective Studies
Birth weight; Gestational age; Placenta; Placental weight