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PP118. Is the placental mass associated with the severity of preeclampsia?
M Baumann1, M Marti1, L Durrer1
1Obstetrics and Gynecology, University Hospital of Bern, Bern, Switzerland.
Insights
Placental mass does not correlate with preeclampsia severity. Maternal response, not placental size, likely dictates disease progression after initial triggers.
Area of Science:
- Obstetrics and Gynecology
- Perinatal Medicine
- Pathophysiology
Background:
- Preeclampsia (PE) is a significant cause of maternal and fetal morbidity and mortality.
- The placenta is believed to play a crucial role in PE pathogenesis, though its exact mechanisms remain unclear.
Purpose of the Study:
- To investigate the relationship between placental mass and the clinical severity of preeclampsia.
- To determine if placental weight influences the manifestation of moderate, severe PE, and HELLP syndrome.
Main Methods:
- Analysis of 208 placentae from singleton pregnancies with preeclampsia.
- Comparison of placental weights, adjusted for gestational age using the observed/expected (O/E) ratio.
- Statistical analysis using Chi-squared and Kruskal-Wallis tests (p<0.05 significance).
Main Results:
- Most placentae (69.2%) weighed below the 10th percentile.
- While mean placental weights differed between PE severity groups, these differences were not statistically significant after adjusting for gestational age (O/E ratio).
- Severe PE and early delivery were strongly associated.
Conclusions:
- Placental mass is not significantly associated with preeclampsia severity.
- Maternal factors, rather than placental size, are hypothesized to modulate PE severity once initiated by placental factors.
Introduction:
Preeclampsia contributes to an increased perinatal morbidity and mortality of both the mother and the fetus. The exact pathogenesis of PE is unclear; it is generally believed, however, that the placenta plays a pivotal role in this process.
Objectives:
The aim of this study was to analyse the effect of the placental mass on the severity of PE.
Methods:
Following PE placentae were analyzed and their weights were compared with those of normal pregnancies [1]. Moderate and severe PE as well as HELLP syndrome were defined according to international guidelines. To compare placental weights obtained at different gestational ages, a ratio between observed (O) and expected (E) weights were calculated. Chi(2)-test and Kruskal-Wallis-test were used for statistical analysis and significance was considered when p<0.05.
Results:
Two hundred and eight placentae following singleton pregnancies complicated by preeclampsia were enrolled. The mean gestational age at birth was 31.8±3.8 weeks, 130 (62.5%) cases delivered before the 34th week. The group with severe PE delivered earlier than that with moderate PE (mean±SD, 32±3.9 vs. 34±3 weeks; p<0.01). Severe PE was found in 176 (84.6%) cases; 85 of this group were associated with a HELLP-syndrome. Isolated HELLP were found in 4 (1.9%) cases. In 144 (69.2%) cases placental weight was below the 10th percentile. The mean of the weights was higher in the group with moderate PE than in those with severe PE, PE with HELLP and isolated HELLP (410±67g, respectively, 376±79g, 344±86g, 341±88g). When normalized using the O/E-ratio (in order to correct for gestational age) these differences were not significant (moderate PE 0.75±0.24; severe PE 0.74±0.22, PE with HELLP 0.73±0.22; isolated HELLP 0.88±0.05; p=NS).
Conclusion:
Our data show that the placental mass is not associated with the severity of PE. We hypothesize that once the pathogenesis of PE is triggered (by placental factors), the severity of the disease is modulated mainly by the maternal response and not by the placental mass.
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