Anticoagulation and in vitro fertilization and ovarian stimulation

Abstract

Assisted reproductive technology is widely used to treat couples affected by infertility. Complications associated with assisted reproduction include venous thromboembolism, ovarian hyperstimulation syndrome, and recurrent implantation failure. It has also been proposed that thrombophilia may be associated with an increased likelihood of these events. Although data are limited, antithrombotic therapy is frequently used to enhance the likelihood of successful assisted reproduction. This chapter reviews the risks of venous and arterial thromboembolism associated with assisted reproduction, as well as available data regarding the impact of thrombophilia on the risks of thromboembolism and failure of implantation. The role of antithrombotic therapy in reducing the likelihood of these events, along with recommendations from various guidelines, are also discussed. Learning Objectives• To discuss the available data regarding the role of thrombophilia testing in women undergoing assisted reproduction • To describe the state of the evidence with respect to the use of antithrombotic therapy in women undergoing assisted reproduction

Does low‐dose aspirin improve pregnancy rate in women undergoing frozen‐thawed embryo transfer cycle? A pilot double‐blind, randomized placebo‐controlled trial

“…However, each of these meta‐analyses had different inclusion and exclusion criteria and used dissimilar analysis methods. In these meta‐analyses, randomized controlled studies were included in which low‐dose aspirin was compared with placebo or no treatment and the dose, duration and timing of aspirin administration varied among the studies …”

“…The patients in our study were treated with FET cycle (nonstimulated cycle), whereas in other above‐mentioned studies, the patients underwent stimulation. Compared to frozen‐thawed cycles, fresh cycles have higher estradiol levels . In FET cycles, the endometrium is artificially primed by estrogen and progesterone.…”

“…The high estrogen levels associated with ovarian stimulation may increase the platelet and coagulation activities leading to a procoagulant state . It has been suggested that thrombophilia leads to the formation of local microthrombosis at the site of implantation, which consequently impairs the ability of syncytiotrophoblast to invade maternal vessels . Results from a recent review study on the association between thrombosis and assisted reproductive technology based on 61 reports on venous thrombosis, showed that in the vast majority of cases (98%), thrombosis occurred after ovulation induction.…”

Failure of fertility therapy and subsequent adverse cardiovascular events

“…40,41 Additional potential options to protect against thromboembolism might include the control of risk factors or prophylactic antiplatelet therapy. 42 In contrast, an observed decreased risk of coronary events following fertility therapy failure appears inconsistent with the hypothesis that endothelial dysfunction may already be present in women at risk of miscarriage and may become accentuated by fertility therapy failure. 19 Alternatively, fertility treatment may be innocuous and merely unmask a latent predisposition to premature cardiovascular disease among individuals at risk of infertility.…”

Recurrent Implantation Failure and Low Molecular Weight Heparin

“…Defined "early" when a negative urine or blood pregnancy test is done 10 to 12 days after embryo transfer (no evidence of implantation with no detectable hCG) or "later" following successful migration of the embryo, hCG produced may be detected in the blood or urine but the process is disrupted before an intrauterine sac is visible on ultrasound (evidence of implantation with detectable HCG, biochemical pregnancy) [3]. IF is the result of failed implantation, placentation or compromise of early development [6]. …”