The effect of antithrombotic therapy on the recurrence of placenta-mediated diseases in pregnancy

Abstract

Objectives To analyze the recurrence rate of placenta-mediated diseases (PMDs) such as preeclampsia (PE) and/or intrauterine growth restriction (IUGR), intrauterine fetal death (IUFD), and placental abruption (PA) in high-risk patients on antithrombotic therapy (AT) because of a previous obstetrical history for such complications. Methods The study group (SG) included 150 patients to whom either 100 mg of aspirin or low-molecular weight heparin (LMWH) was administered due to a previous history of PMDs. The AT in the SG was started before 16 gestational weeks (g.w.). The patients in the first control group (CG-1) were 150 who also had a previous obstetrical history of PMDs, but did not receive antithrombotic therapy (AT) throughout their ongoing pregnancies. The second CG (CG-2) comprised 320 patients with a previous history of normally developing pregnancies and without AT throughout their ongoing pregnancies. Results The total percentage of PE in pregnant patients from the SG was 25.3% (38/150 patients), with 22.2% (10/45) in the SG on AT only with LDA (SG-LDA group), 25% (17/68) in the SG on AT only with LMWHs (SG-LMWH group) and 29.7% (11/37) in the SG on combined AT with LDA and LMWHs (SG-LDA + LMWH group), as opposed to 18.67% (28/150) in CG-1 and 0.62% (2/320) in CG-2. The recurrent severe PE/total PE ratio in the SG was 44.7% (17/38), with 30% (3/10) in the SG-LDA group, 47% (8/17) in the SG-LMWH group and 54% (6/11) in the SG-LDA + LMWH group, against 75% (21/28) in CG-1. There were no cases with severe PE in CG-2. All cases with recurrent IUGR from the SG were equal to 13.3% (20/150), with 13.3% (6/45) in the SG-LDA group, 11.76% (8/68) in the SG-LMWH group and 16.2% (6/37) in the SG-LDA + LMWH group, as compared to 30% (45/150) in CG-1 and 5% (16/320) in CG-2. As a whole, the overall recurrence rate of PMDs in the SG was 38.67% (58/150), with 35.56% (16/45) in the SG-LDA group, 36.76% (25/68) in the SG-LMWH group and 45.9% (17/37) in the SG-LDA + LMWH group, as compared to 50.67% (76/150) in CG-1 and 5.94% (19/320) in CG-2. Conclusion AT had a partial beneficial effect on the prophylaxis of recurrent PMDs. On the one hand, AT led to a significant reduction in the recurrent severe PE/total PE ratio, as well as in the total PMDs’ recurrence rate in the SG as compared to the one in CG-1. On the other hand, the percentage of recurrent PMDs still remained significantly higher in the SG as compared to CG-2. Pregnant patients with previous PMDs still need close surveillance in subsequent pregnancies as they remain at a high risk for complications.