TITLE:
Recurrent Implantation Failure and Low Molecular Weight Heparin
AUTHORS:
Dalia Khalife, Ghina Ghazeeri
KEYWORDS:
Heparin, Low-Molecular-Weight Heparin, Recurrent Implantation Failure, Thrombophilia, Anti-Coagulation, Assisted Reproductive Technologies
JOURNAL NAME:
Open Journal of Obstetrics and Gynecology,
Vol.8 No.2,
February
12,
2018
ABSTRACT: Implantation of the embryo into the endometrium is the first step in the
establishment of pregnancy. This process is complex, and depends on many
factors. Recurrent implantation failure is a source of distress to patients and
specialists. It is defined as failure to achieve a viable pregnancy, following
“>3 embryo transfers with high quality embryos or the transfer of ≥ 10
embryos in multiple transfers”. Thrombophilic conditions that contribute to
recurrent implantation failure are the main concern in this review. The mechanism of implantation failure
is believed to be due to decreased blood flow to the endometrium and placenta
which can hinder normal endometrial receptivity leading to miscarriage. Defects
in early placentation resulting in pregnancy failure, have focused attention on
the therapeutic potential of low molecular weight heparin in the implantation
process. Heparin has a role at all stages of implantation to improve pregnancy
outcomes. There are controversies in literature regarding the association
between thrombophilia and recurrent implantation failure and available literature
regarding this issue is very heterogeneous. Various investigators, have shown
that women with RIF are more likely to have a thrombophilia disorder, yet a
clear cause cannot be acknowledged from these studies. Heparin treatment has
been evaluated in several studies, showing conflicting evidence. However,
several studies have pointed out that it may play a role in a subset of
patients who presents a thrombophilia mutation, thus the group of patients that
might benefit is needed to be identified. This review is dedicated to evaluate the
published literature about the role of low molecular weight heparin in case of
recurrent implantation failure with or without the presence of thrombophilia.