Background: Chronic deciduitis is a chronic inflammatory placental disease. It is associated with severe perinatal complications, especially recurrent miscarriage, preterm birth, preterm labor, and preterm prelabor rupture of membranes.

Methods: This study presents a detailed quantification of plasma cells and lymphocytes, and regards clinicopathological associations concerning different trimesters in 99 cases displaying chronic deciduitis with plasma cells (CD), 23 cases from the second trimester and 76 cases from the third trimester, respectively. The control group without CD consisted of matched placentas concerning the gestational weeks.

Results: In every instance lymphocytes were more numerous than plasma cells. The mean value/highest score in ten high power fields were 50/321 for plasma cells, and 460/995 for lymphocytes, respectively. In the second trimester the scores for plasma cells were significantly higher than in the third trimester. In the third trimester preterm labor occurred significantly more often in cases with chronic deciduitis related to the control group (P < .05).

Conclusion: In chronic deciduitis the plasma cell count is usually higher in the second compared to the third trimester. A brisk infiltration of the decidua with plasma cells could probably point to a more severe clinical manifestation and a higher risk for preterm labor and preterm birth.

背景：慢性蜕膜炎是一种慢性炎症性胎盘疾病。它与严重的围产期并发症有关，尤其是反复流产、早产、早产和早产胎膜早破。

方法：本研究对浆细胞和淋巴细胞进行了详细的量化，并考虑了 99 例伴有浆细胞 (CD) 的慢性蜕膜炎患者、23 例来自妊娠中期的病例和 76 例来自妊娠晚期的 76 例的不同妊娠期的临床病理学关联。没有 CD 的对照组由与妊娠周相关的匹配胎盘组成。

结果：在每种情况下，淋巴细胞都比浆细胞多。10 个高倍视野的平均值/最高分分别为浆细胞 50/321 和淋巴细胞 460/995。在孕中期，浆细胞的分数明显高于孕晚期。与对照组相关的慢性蜕膜炎病例在妊娠晚期的早产发生率明显更高（P < .05）。

结论：在慢性蜕膜炎中，与妊娠晚期相比，妊娠中期的浆细胞计数通常较高。浆细胞对蜕膜的快速浸润可能表明更严重的临床表现和更高的早产和早产风险。