Search

Implantation failure is common in assisted reproduction techniques (ART). The role of low-molecular-weight heparin (LMWH) is a matter of debate as a potential factor to improve implantation. Aim: To evaluate the pregnancy rate in patients with or without heparin administration. Materials & methods: We performed a retrospective observational analysis of patients with at least two IVF/intracytoplasmic sperm injection cycles with implantation failure, screened for inherited thrombophilia and submitted to further ART cycles with or without administration of LMWH. A total of 265 patients fulfilled the enrollment criteria. Of these 149 (56%) were primary infertile and 116 (44%) were secondary infertile. Their mean age was 36.3 ± 3.6 years. We analyzed basal FSH, smoking habit, gene variants for inherited thrombophilia (i.e., MTHFR C677T, prothrombin G202A10G and factor V Leiden). The patients underwent 569 new ART cycles: 512 (90%) without and 57 (10%) with LMWH. Results: In total 105 clinical pregnancies were observed in 569 cycles (18.8%). The pregnancy rate was 17.19% (88/512) in patients not treated with LMWH and 29.52% (17/57) in the LMWH-treated group (p = 0.006). In women over 36 years of age the pregnancy rate was 15.53% (50/322) in nontreated versus 35.71% (10/28) in treated cycles (p = 0.007), while no difference was found in younger women. No statistical difference was found between the presence of inherited thrombophilia and pregnancy rate in treated and untreated cycles. Discussion: significantly higher pregnancy rate in patients with previous ART implantation failures was observed with LMWH. Our results confirm no relation among inherited thrombophilia and pregnancy rate in patients with previous IVF implantation failures. These findings should be confirmed by randomized controlled trials before use of LMWH for ART cycles is recommended.

Antiplatelet therapy is the cornerstone in the modern therapy of patients with acute coronary syndromes (ACS), because of the unique role of platelets in coronary thrombosis. Clopidogrel in combination with aspirin is the current “gold standard” for reducing cardiovascular events in such patients, providing a synergistic platelet inhibition through different platelet activation pathways. Clopidogrel is a thienopyridine which inhibits ADP-induced platelet aggregation, with no direct effects on the metabolism of arachidonic acid. Due to a better safety profile with a similar antiplatelet effectiveness, it is preferred to ticlopidine. In patients with ACS without ST segment elevation (NSTEMI), clopidogrel plus aspirin is able to reduce the relative risk of adverse cardiovascular events by 20%, compared with aspirin alone. Clopidogrel plays a key role also in patients undergoing coronary stenting, in order to prevent stent thrombosis. Pretreatment and long-term treatment with clopidogrel reduces by about one-third the risk of cardiovascular death or myocardial infarction in NSTEMI ACS patients undergoing percutaneous coronary angioplasty (PCI). However, a long-term dual antiplatelet therapy is associated with a higher rate of bleeding events. Clinical practice guidelines currently recommend long-term dual antiplatelet therapy with aspirin and clopidogrel in patients with ACS and a pre-treatment with clopidogrel in every patient scheduled for PCI. The concept of clopidogrel resistance and the need for a pretreatment in patients undergoing coronary stent implantation led to the concept that an improved antiplatelet regimen with novel drugs is desirable.