When IVF Fails: Exploring Reasons for Implantation Failure - Part 3
EMBRYO DEVELOPMENT/UTERINE LINING NOT SYNCHRONIZED
There is evidence that transferring frozen embryos results in better outcomes and healthier babies, and some leaders in the field of reproductive endocrinology are advocating freezing ALL embryos and transferring the frozen/thawed embryos in a separate cycle that more closely mimics the natural cycle. Recent studies have demonstrated the following:
- Higher clinical pregnancy rates following frozen embryo transfer versus fresh transfer.
- Single pregnancies from frozen embryo transfers have significantly better neonatal outcomes than offspring from fresh transfers
- Birth weight was significantly higher in siblings born after frozen embryo transfers compared with fresh embryos
EMBRYONIC CHROMOSOMAL ABNORMALITIES (ANEUPLOIDY)
One study has demonstrated that patients with recurrent miscarriage are 1.35 times more likely to have a chromosomally abnormal (aneuploidy) embryo.
When all embryos were subjected to comprehensive chromosomal screening, with only chromosomally normal embryos transferred, live birth rates were more than 20% higher compared to the control group in which embryos were transferred based on their microscopic appearance.
Most experts agree that immunologic causes for reproductive failure exist. Unfortunately, precise means of diagnosing and treating these disorders has proven elusive.
Intravenous immunoglobulin therapy (IVIG) has been looked at as potential treatment for couples with repeat implantation failure. A study authored by Stephenson and Fluker (2000) looked at 51 couples with repeat implantation failure and showed that IVIG did not improve the live birth rate.
In two large randomized controlled trials heparin and aspirin did not improve embryo implantation rates (Urman et al., 2000).
A study that examined the use of paternal leukocyte immunotherapy (Carp et al.,1994) was not shown to improve embryo implantation rates.
The relationship between endometriosis and infertility is well established. In patients with repeat implantation failure, treating for 3-6 months with injectable agents to suppress endometriosis (GnRH agonists) significantly increased the ongoing pregnancy rate (Surrey et al., 2002).
A large study published in 2006 (Sallam et al.) showed that endometriosis treatment before IVF did not result in an adverse effect on the ovarian response to stimulation and did improve the odds of a clinical pregnancy.
The question of whether to surgically remove endometriosis cysts (endometriomas) before IVF has been looked at and at least one study has shown no benefit (Garcia-Velasco et al., 2004). Some have suggested that surgery might have adverse effects on ovarian reserve.