It has been suggested that in women who have persistently thin uterine lining
or who have experienced multiple failed embryo transfers, giving them a treatment
known as G-CSF before embryo transfer may improve their chances for IVF success.
There is a scientific theory that injecting G-CSF into the uterine cavity may increase IVF success
by helping to thicken the uterine lining or by increasing the chance for an embryo to
implant and produce a pregnancy. Does it really work? What does the science say? Stay tuned.
G-CSF is an abbreviation for Granulocyte - Colony Stimulating Factor. You may also
hear it referred to as Leucostim or filgrastim. G-CSF is a type of growth factor that stimulates
bone marrow to produce certain types of white blood cells. In the uterine lining,
G-CSF promotes regenerative activity of the cells and helps in increasing the blood supply.
When we look at the studies that have used G-CSF in IVF we find two things. One
is that the overall quality of these studies was not very good and two,
some studies appear to show a benefit and others did not.
If you are a subscriber to Infertility TV,
you know that whenever we have a situation when there are lots of small studies with conflicting
results, we go looking for a meta analysis. A meta analysis combines the results from a
bunch of smaller studies into one larger study to improve the chances of finding an accurate result.
We found this meta analysis of 13 studies involving 522 women who received
G-CSF and 528 women who received placebo or no additional treatment during IVF. There was some
pretty advanced statistical analysis here which I won’t bore you with. What was the bottom line?
There were three different questions that this meta attempted to answer
Question #1 - Does G-CSF help thicken the uterine lining? This analysis was
unable to find any benefit to making the uterine lining thicker.
Question #2 -- Did G-CSF improve the chance for becoming pregnant,
having an ongoing pregnancy or a live birth? No, no and no.
What about couples who had two or more previous failed embryo transfers? Also, no.
Question #3 - Did G-CSF lower the risk for miscarriage? Finally, no!
Based on the results of these 13 studies, it does not appear that G-CSF is helpful.
However, at about the same time that this meta analysis was published,
another study was published looking at G-CSF. This study was larger than any of the studies in the
meta analysis so the results could potentially change the results of the meta analysis. The
quality of this study was also much better than most of the other studies.
This study looked at couples with recurrent implantation failure.
That is the failure to achieve a clinical pregnancy after the transfer
of at least four good-quality embryos in a minimum of three fresh or frozen cycles
to a woman under the age of 40 years. 82 women received G-CSF and the rest just had saline
which is salt water. The patients did not know who received the G-CSF and who got the placebo.
When they looked at the results they found that the G-CSF patients did not have a better
pregnancy rate or live birth rate. There was no difference in the risk for miscarriage
and the uterine lining wasn’t any thicker.
Our InfertilityTV Bottom Line is this. At the current time, the best scientific evidence
does not support the use of G-CSF to thicken the uterine lining or
improve IVF success. If you want to enroll in a study, that’s fine but you should not
be charged for this treatment until it can be proven that there is a benefit