Does Enoxaparin treatment have any effects on the placenta in women with unexplained histories of habitual abortion? A case control study

Abstract

BACKGROUND: It is very common to offer low molecular weight heparin (LMWH) medications to women with unexplained habitual abortion, to increase the livebirth rate. Although no benefit from LMWH has been clearly demonstrated, examination of the effects of enoxaparin on placental structure is lacking. OBJECTIVE: To assess placental structural changes in pregnancies treated with enoxaparin, compared with controls. DESIGN AND SETTING: Case-control study in an obstetrics and gynecology unit of a tertiary-level university hospital in Turkey. METHODS: Forty patients who had had term pregnancies and live births but also histories of habitual abortion were recruited for this study. Placentas were sampled using a systematic random sampling method. Tissue samples were obtained, embedded and sectioned for routine histological analyses. Hematoxylin and eosin staining was used. Surface area and length estimates from placental components were evaluated by using Image J. Cell proliferation and apoptosis were also assessed via immunohistochemistry. RESULTS: There were no significant differences between the groups regarding maternal age, abortion rate, birth weight or gestational age. Comparison of the enoxaparin and control groups showed that there were no significant differences in terms of surface area and ratios of placental components. We found that Bcl-2 was generally expressed at high levels in the enoxaparin group, while there was no difference in terms of Ki-67 between the groups. CONCLUSIONS: This study demonstrates that enoxaparin did not show any significant effect on the placental structure of cases that had histories of habitual abortion.

Does the use of low-molecular-weight heparin during pregnancy change the expression of PD-1 and PDL-1 in women with recurrent pregnancy loss?

“…However, there was no significant difference between the healthy pregnant group (G1). In the study of Ozdemir et al, ( 13 ) it was stated that the changes in the structure of the villi and the intervillous area in the placentas of patients using LMWH were similar to our findings. However, there was no significant difference in the statistical comparison with the healthy pregnant group ( 13 ) .…”

“…Evaluation of placental morphology in the investigation of placental diseases is essential for understanding the pathogenesis of these diseases. This process involves the differentiation, migration, and division of a large number of cells and creates extensive vascularization ( 13 ) .…”

“…Decreased surface area, volume, and vascularization of terminal and intermediate villi mediate maternal-fetal exchange. Perivillous fibrin deposition is characterized by the clustering of eosinophilic fibrin around the villi, and fibrin deposition impairs oxygenation around the villi, which also affects the morphology of the villi ( 13 , 15 , 16 ) .…”

“…They were divided into three groups: G1- healthy pregnancy (n=20), G2-RPL but not administered LMWH (n=20), and G3-RPL and administered LMWH (n=20). Placental tissues retrieved at birth were sampled using a random sampling method ( 13 , 14 ) . All patient groups were selected from singleton pregnancies and patients who had a live birth in the last trimester of their pregnancy.…”

“…Immediately after birth, the cord and placental membranes were carefully cleaned and fixed in 10% neutral buffered formalin for 24 h. Unbiased tissue sampling for each placenta was performed using a uniform random sampling protocol ( 13 , 14 ) . The removed tissues were blocked by passing through increasing ethyl alcohol levels, xylol, and warm paraffin as per the routine histological tissue follow-up procedure.…”