Certain Genes Increase IVF Success
Reported November 21, 2011
(Ivanhoe Newswire) – The success rate of IVF seems to be increasing!
According to a recent study conducted by researchers at Cincinnati
Children’s Hospital Medical Center, increasing expression of certain
developmental genes at precise times in the uterus might improve pregnancy
rates from in vitro fertilization-embryo transfers, IVF-ET, which remains
low at around 30 percent.
Researchers point to the genes Msx1 and Msx2, which play integral roles in
organ formation during fetal development, as essential to ensuring the
uterus is in a receptive phase needed for successful embryo implantation.
Compromised uterine receptivity is a major cause of pregnancy failure in IVF
programs, according to Sudhansu K. Dey, PhD, and director of the Division of
Reproductive Sciences in the Perinatal Institute at Cincinnati Children's.
Babies successfully conceived through IVF have a higher risk of being born
prematurely, which can result in a number of potential short and long-term
health risks for the child. Identifying essential molecular signaling
pathways at critical stages of early pregnancy in IVF patients could lead to
new approaches for optimizing pregnancy outcome.
"Our findings raise the possibility that clinicians may be able to develop
new strategies to improve implantation rates in IVF programs by temporarily
increasing uterine levels of Msx,” Dey was quoted as saying, "This could
allow clinicians to potentially extend the window of uterine receptivity and
grant transferred embryos more time to implant."
Through a series of experiments using genetically engineered mice, the
researchers determined the loss of Msx genes is associated with detrimental
reproductive consequences in a key molecular pathway involving Wnt
signaling; a pathway that plays a central role in embryo development. As a
result of Msx loss, uterine luminal epithelial cells respond improperly and
fail to assume a slit-like architecture that forms the point of place the
organism originates, necessary for playing the embryo for successful
Gene-deleted mice in the study exhibited graded levels of compromised
fertility depending on a single or double deletion of the Msx gene. Mice
singly deleted of Msx1 produced either smaller than normal litter sizes or
no litters at all, while deletion of both Msx1 and Msx2 genes resulted in
complete infertility because embryos failed to implant.
Gene analysis has shown that Msx genes are differentially expressed in the
uterus during the menstrual cycle in women. This suggests the possibility
that genes identified in the current study may have important roles during
The present findings also show that Msx genes convey and maintain uterine
receptivity without altering ovarian hormone levels or uterine sensitivity
to these hormones. Dey and his colleagues believe that, in addition to its
potential in improving IVF-derived pregnancy outcomes, further uncovering
the role of Msx may aid in the development of non-steroidal contraceptives.
Although further investigation is warranted to apply the findings to human
fertility, the researchers say they are a step forward in understanding a
molecular network that regulates female fertility and is subject to
SOURCE: Developmental Cell, November 17, 2011