Brien ME, et al. - This study is performed to comprehend the dynamic changes occurring in the maternal immune system in the perinatal period in normal pregnancies or pregnancies with complications (preeclampsia (PE) and the postpartum period (PPPE)). Altogether, these outcomes propose that changes in the immune system occur rapidly following delivery and that these changes are abrogated, or delayed in PE. Additionally, women with seemingly normal pregnancies that later develop PPPE have altered the immune system. The lack of immune activation could be utilized to recognize women at high-risk of PPPE.

Methods

• For this study, women were selected at Sainte-Justine Hospital with uncomplicated term pregnancies (Ctrl, N=20), PE (PE, N=20) or normal pregnancies with postpartum PE (PPPE, N=20).
• Blood samples were collected prior and 24h after delivery in all patients and at the time of diagnosis (PPPE).

Results

• Delivery was related to rapid changes in the maternal circulating immune system with elevation of the total leukocyte and neutrophils numbers and decreased lymphocytes and monocytes in Ctrl.
• In pregnancies with PE, leukocytes and neutrophils count were already elevated prior to delivery vs Ctrl and remained elevated 24h after delivery.
• Lymphocyte levels, on the other hand were similar to Ctrl prior to birth and significantly elevated after delivery.
• For PPPE, leukocytes and neutrophils count were similar to Ctrl prior to delivery but did not rise following birth and were significantly lower at the time of PPPE diagnosis.
• Moreover, lymphocytes were significantly elevated at PPPE diagnosis.