Dr. Coutifaris, who is president of the American Society for Reproductive Medicine, said a higher progesterone level may indicate that the development of the embryo and the womb are out of synch, and using a thawed embryo allows for better timing of the implantation.
In one study of 2,157 ovulatory women with infertility in China, the live-birth rate did not differ significantly between the frozen-embryo group and the fresh-embryo group (48.7% and 50.2%, respectively; RR 0.97, 95% CI 0.89-1.06, P=0.50), reported Zi-Jiang Chen, MD, PhD, of Shandong Provincial Hospital, and colleagues.
Before freezing methods were refined, fresh embryos were the only option, but as cryopreservation techniques improved, freezing embryos so that not all of the healthiest ones had to be transferred to the woman immediately became more popular.
Whereas in women with polycystic ovary syndrome (PCOS), freezing and thawing embryos before implantation offers a better chance of pregnancy and birth, in women without this condition thawed embryos and are no better or worse than fresh embryos, researchers in China and Vietnam have found.
Live births were recorded in 33.8 per cent of the frozen-embryo group and 31.5 per cent of women in the fresh-embryo group.
Freezing embryos also allows couples to take advantage of genetic testing, which can pick up potentially lethal genetic diseases and guide doctors in deciding which embryos to implant.
Results from two Asian studies suggest that frozen embryos may be comparable to fresh ones for women having in vitro fertilization (IVF), researchers reported.
"The importance of these papers is that it documents what we know", says Dr. Jamie Grifo, program director of the New York University Fertility Center, who was not involved with the studies.
Women were given one cycle of IVF, where either a transfer of fresh embryos occurred, or all embryos were frozen and one cycle of thawed embryos occurred subsequently without the use of IVF drugs. Until 2012 or so, the majority of clinics in North America favoured fresh embryo transfer.
"There are many examples in medical history where people jump to innovation and new things, and then after a while it turns out that the new thing is not necessarily so much better", Mol said. All women had regular menses and were undergoing their first cycle of IVF or intracytoplasmic sperm injection because of tubal factors, male factors, or both. There were no differences in pregnancy rate or live birth rate, nor pregnancy complications such as high blood pressure.
"It's not a lot, but it's a couple of hundred of dollars that you're talking about, so obviously that could be part of the choice [for patients]", he said. Vitrification does not harm the embryos and they can be stored indefinitely.
Researchers called this an "insignificant difference".
"Health systems in other countries make it more possible to do proper randomised control trials, so it's excellent that we are getting those relationships built up", Chapman said.
Xerox in major deal talks with Fujifilm; XRX +3.8%
The institutional investor owned 40,000 shares of the company's stock after selling 80,000 shares during the period. The company reported $0.25 earnings per share (EPS) for the quarter, meeting analysts' consensus estimates of $0.25.
$1.84 EPS Expected for Honeywell International Inc. (HON)
Trust Company Of Virginia increased its stake in Visa Inc (V) by 33.62% based on its latest 2017Q3 regulatory filing with the SEC. The sale was disclosed in a filing with the Securities & Exchange Commission, which is accessible through this hyperlink .
Norman North's Drake Stoops Will Walk On at Oklahoma
He also turned down Air Force, Arkansas State, Memphis, Ohio, Western Kentucky and Youngstown State to walk-on at OU. Stoops caught 66 passes for 1,093 yards and 14 touchdowns at Norman North this past season.