主页 > 医学动态 >
【medical-news】不育研究新突破可使IVF成功率翻倍
LAS VEGAS, Jan. 29 /PRNewswire/ -- A process that could markedly improve pregnancy rates from In Vitro-Fertilization (IVF) was reported in a study published in the prestigious medical journal Fertility and Sterility(F&S).
"This very exciting breakthrough could more than double IVF pregnancy success rates while reducing the risk of multiple births. We are now much closer to the goal of one IVF attempt, one egg, and one embryo, yielding one healthy baby," said Dr. Geoffrey Sher, who along with Levent Keskintepe PhD , both of ReproCure, LLC and the Sher Institutes for Reproductive Medicine(SM) (SIRM) developed the process and conducted the study.
High Order Multiple Births
"Hitherto, the inability to reliably identify the embryos most likely to produce a healthy baby is the primary reason why most IVF practitioners have tended to transfer numerous embryos at one time to the uterus," added Dr. Sher. "Albeit well intended, this has led to a veritable explosion in the incidence of IVF-related high order multiple births (triplets or greater) with serious medical, social and financial consequences."
Noted Dr. Keskintepe: "Our research has finally provided a reliable method for identifying competent embryos. We have taken a quantum step towards achieving the previously elusive objective of maximizing IVF success while significantly lowering the risk of multiple births and minimizing pregnancy loss."
The Reported Study
The report describes a process involving complete chromosome analysis using a method known as Comparative Genomic Hybridization (CGH) by which they tested DNA derived from a small egg chromosomal structure known as the first Polar body (PB-1), located immediately below the egg surface. This allowed the researchers to identify and then selectively fertilize only those eggs that had a full complement of chromosomes (i.e. were chromosomally normal) and were thus deemed highly likely to be "competent"
(i.e. capable upon fertilization of developing into chromosomally normal,
"competent" embryos).
The researchers then transferred one (1) or two (2) embryos derived from "competent" eggs to the uteri of 35 study participants. Twenty eight (80%) of the women achieved ultrasound-confirmed pregnancies, 26 (74%) of whom thereupon went on to spawn healthy babies (6 sets of twins; 32 total babies). This is more than double the expected IVF birth rate.
The report also revealed the incidence of egg chromosomal abnormalities (aneuploidy) to be 65% (far greater than was previously reported) and also showed that fertilization of aneuploid eggs invariably propagated embryos that were "incompetent" (i.e. incapable of producing healthy babies). Uterine transfer of even a single such "competent embryo" resulted in a healthy baby approximately 70% of the time.
"Our new-found ability to drastically improve IVF pregnancy outcomes, while at the same time reducing the risk of multiple births and birth defects, makes a strong case in favor of universal insurance coverage for IVF and could provide a much needed shot in the arm for embryonic stem cell research."
A New Study: Egg Freezing
Drs. Sher and Keskintepe recently embarked on a second study to determine whether identifying (through PB-1, CGH) and then selectively ultra-rapidly freezing (vitrifying) only "competent" (chromosomally normal) eggs would improve hitherto poor post-thaw egg survival rates and subsequent IVF outcomes, following fertilization and transfer of pre-frozen eggs.
"By using CGH to identify and select 'competent' eggs for freezing by vitrification, which is a new freezing method that avoids doing damage to the egg, we are now poised to make great strides in the egg cryobanking arena. In fact using the CGH/Vitrification process, we have already been able to show that 95% of the 'competent' eggs that were vitrified survived the thaw and that 60% of these, following fertilization, developing into advanced embryos or blastocysts," said Dr. Sher. He then went on to announce that he and Dr. Keskintepe had so far transferred 1-2 blastocysts (derived from pre-vitrified eggs) to the uterus of each of 13 women and that on January 18th 2007, the first of 7 viable pregnancies (54%) resulted in a live birth. The remaining pregnancies were well advanced and progressing normally.
"These findings, should they be corroborated through independent studies, could initiate a paradigm shift in the entire field of Reproductive Medicine," added Dr. Keskintepe.
ReproCure, LLC is currently involved in beta site confirmational studies in both the USA and the UK.
SOURCE: Sher Institutes for Reproductive Medicine
http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=104&STORY=/www/story/01-29-2007/0004514884&EDATE=
阅读本文的人还阅读：
作者:admin@医学,生命科学 2011-03-15 17:12
医学,生命科学网