Wednesday, February 25, 2009
Bacteria in semen influences sperm quality
Investigators studied bacterial contamination in sperm samples of 1256 men at an infertility clinic. The presence of bacteria in semen samples is closely associated with sperm quality, their research shows.
The contamination of sperm samples by some bacteria species is also closely associated with infertility, report Elena Moretti, from the University of Siena, Italy, and colleagues.
Over an 8-year period, 1,256 male individuals were referred to an infertility clinic for semen analysis. The median duration of infertility was 3.75 years of unprotected intercourse without conception.
Spermiogram, semen culture, and sperm transmission electron microscopy (TEM) were performed, along with a culture test to identify common bacteria that colonize the male reproductive tract.
Overall, 33% of men had bacteria in their semen samples.
Within each bacteria species identified, fertile men had semen quality similar to that of uninfected controls. On the other hand, sperm quality was significantly decreased among infertile men.
"Bacteria in semen samples may influence the sperm quality, mainly by the induction of apoptosis and necrosis, which may in part be responsible for the observed reduction of sperm motility," suggest the researchers.
Source: Journal of Assisted Reproduction and Genetics 2008; Advance online publication
The contamination of sperm samples by some bacteria species is also closely associated with infertility, report Elena Moretti, from the University of Siena, Italy, and colleagues.
Over an 8-year period, 1,256 male individuals were referred to an infertility clinic for semen analysis. The median duration of infertility was 3.75 years of unprotected intercourse without conception.
Spermiogram, semen culture, and sperm transmission electron microscopy (TEM) were performed, along with a culture test to identify common bacteria that colonize the male reproductive tract.
Overall, 33% of men had bacteria in their semen samples.
Within each bacteria species identified, fertile men had semen quality similar to that of uninfected controls. On the other hand, sperm quality was significantly decreased among infertile men.
"Bacteria in semen samples may influence the sperm quality, mainly by the induction of apoptosis and necrosis, which may in part be responsible for the observed reduction of sperm motility," suggest the researchers.
Source: Journal of Assisted Reproduction and Genetics 2008; Advance online publication
Tuesday, February 24, 2009
Blastocyst transfers in older women
A large retrospective study has yielded information on the optimal number of blastocyst stage embryos to transfer on day 5 or 6 in women aged 38 years or older.
Specialists in a Writing Group convened by the USA’s Society for Assisted Reproductive Technology conducted the study, based on data collected by the society between 2000 and 2004. The data related to a total of 5,569 day 5 and day 6 embryo transfers in women aged 38 or older who were undergoing their first assisted reproductive technology cycle. These 5,569 transfers led to 1,667 deliveries.
The researchers used both univariate and multivariate logistic regression to model the probability of delivery, twins, and higher-order multiples based on certain patient characteristics. These were age, the number of embryos transferred, the maximum follicular phase FSH level, the number of oocytes retrieved, cryopreservation of excess embryos, and the use of ICSI.
In their new paper in the current issue of the journal Fertility and Sterility, the researchers report the findings of their analyses. In women aged 38 or 39 years, there was an increase in delivery rates when two embryos were transferred, compared with when one embryo was transferred. Transferring more than two increased the rate of multiples but not delivery.
In women aged 40 years, transferring up to three embryos increased the delivery rate without increasing the multiple rate. In women aged 41 or 42 years, the delivery rate plateaued after the transfer of three embryos, but the twin rate continued to increase.
In the paper, the researchers draw their findings together in order to present the following recommendations on the suggested number of embryos to transfer on days 5 and 6 to minimize the risk of multiples in patients undergoing their first cycle:
Number of oocytes <10 and no cryopreservation:
Maternal age 38 years: 2 embryos.
39 years: 2.
40 years: 2-3.
41-42 years: 3.
43-44 years: 3.
Number of oocytes 10 or more, and/or use of cryopreservation:
Maternal age 38 years: 1-2 embryos.
39 years: 1-2.
40 years: 2.
41-42 years: 2-3.
43-44 years: 3.
Discussing their findings, the researchers note that these recommendations of course “do not represent strict guidelines” but do represent an analysis of outcomes from a large national US dataset. They write: “From this analysis, it appears that, in patients aged 38 to 39 years who are considered candidates for blastocyst transfer, delivery rates can be maximized while minimizing multiple pregnancy rates by transfer of no more than two blastocyst stage embryos.”
The researchers acknowledge that different laboratories can have significantly different stimulation protocols, indications for blastocyst stage transfer, and classifications of embryo morphology, and point out that these differences were not taken into account in the data analyzed and presented.
Source: Fertility and Sterility 2009;91:157-66
Specialists in a Writing Group convened by the USA’s Society for Assisted Reproductive Technology conducted the study, based on data collected by the society between 2000 and 2004. The data related to a total of 5,569 day 5 and day 6 embryo transfers in women aged 38 or older who were undergoing their first assisted reproductive technology cycle. These 5,569 transfers led to 1,667 deliveries.
The researchers used both univariate and multivariate logistic regression to model the probability of delivery, twins, and higher-order multiples based on certain patient characteristics. These were age, the number of embryos transferred, the maximum follicular phase FSH level, the number of oocytes retrieved, cryopreservation of excess embryos, and the use of ICSI.
In their new paper in the current issue of the journal Fertility and Sterility, the researchers report the findings of their analyses. In women aged 38 or 39 years, there was an increase in delivery rates when two embryos were transferred, compared with when one embryo was transferred. Transferring more than two increased the rate of multiples but not delivery.
In women aged 40 years, transferring up to three embryos increased the delivery rate without increasing the multiple rate. In women aged 41 or 42 years, the delivery rate plateaued after the transfer of three embryos, but the twin rate continued to increase.
In the paper, the researchers draw their findings together in order to present the following recommendations on the suggested number of embryos to transfer on days 5 and 6 to minimize the risk of multiples in patients undergoing their first cycle:
Number of oocytes <10 and no cryopreservation:
Maternal age 38 years: 2 embryos.
39 years: 2.
40 years: 2-3.
41-42 years: 3.
43-44 years: 3.
Number of oocytes 10 or more, and/or use of cryopreservation:
Maternal age 38 years: 1-2 embryos.
39 years: 1-2.
40 years: 2.
41-42 years: 2-3.
43-44 years: 3.
Discussing their findings, the researchers note that these recommendations of course “do not represent strict guidelines” but do represent an analysis of outcomes from a large national US dataset. They write: “From this analysis, it appears that, in patients aged 38 to 39 years who are considered candidates for blastocyst transfer, delivery rates can be maximized while minimizing multiple pregnancy rates by transfer of no more than two blastocyst stage embryos.”
The researchers acknowledge that different laboratories can have significantly different stimulation protocols, indications for blastocyst stage transfer, and classifications of embryo morphology, and point out that these differences were not taken into account in the data analyzed and presented.
Source: Fertility and Sterility 2009;91:157-66
Monday, February 23, 2009
Octuplet birth raises questions
Initial reports about a California woman who delivered octuplets last month evoked wonderment over the fact that all seemed to be doing well. But as more details about the woman dribbled out, wonderment turned into disbelief for many. The Associated Press has reported that the mother is a single 33-year-old named Nadya Suleman who already had six children at home, and that all 14 of her children were conceived via in vitro fertilization, or IVF. The octuplets are now the longest-surviving bunch in U.S. history.
The six boys and two girls — whose names have not yet been released — were born weighing between 1 pound, 8 ounces and 3 pounds, 4 ounces.
Kaiser Permanente spokeswoman Socorro Serrano says the babies are all doing well.
The country's first set of octuplets was born to Nkem Chukwu of Texas on Dec. 20, 1998. A week later, the tiniest of the infants died of heart and lung failure. The baby, named Odera, weighed only 10.3 ounces at birth. The surviving seven siblings celebrated their 10th birthday in December.
How Nadya could afford expensive IVF, and why a doctor would transfer enough embryos to result in octuplets, a rare, extremely risky "high-order multiples" pregnancy, is unknown.
"We're certainly trying to find out who the treating physician was so that we can find out the circumstances of the conception," says Sean Tipton, a spokesman for the American Society of Reproductive Medicine.
The octuplets, believed to be only the second set ever born in the USA, have raised a number of questions for fertility specialists:
Q: Are there any laws against transferring more than a few embryos to a woman's uterus?
A: There is in the United Kingdom, which has a national health program, but not in the USA.
To reduce the number of multiple births resulting from IVF, the American Society for Reproductive Medicine (ASRM) and the Society for Assisted Reproductive Technology (SART), one of its member organizations, have drawn up guidelines suggesting limits based on a patient's age and other factors related to her chances of conceiving.
In general, the older women are, the less likely they are to conceive with embryos created with their own eggs. Under ASRM guidelines, only one or two embryos should be transferred to women under 35. The upper limit in women over age 40 is five.
SART could revoke a clinic's membership for blatantly ignoring its guidelines, Tipton says. "Being a member of SART is an important credential, because many insurance companies who pay for IVF will only pay for it at SART clinics," he says.
Q: What are the odds that every embryo will "take" and result in a baby?
A: Remote, says Terrence Lee, a reproductive endocrinologist in Brea, Calif., who writes a blog called Fertility File. "If you hear that a baseball player got eight hits last week, you usually don't think that he had only eight at-bats." Eight babies suggests many more embryos were transferred.
Q: Can't doctors just say no when patients ask that more than the recommended number of embryos be transferred, especially if they question a woman's ability to care for multiples?
A: Not really. The ASRM ethics committee addressed the question in 2004, when it said fertility programs can withhold services only if they have "well-substantiated judgments" that the patient won't be able to provide adequate child-rearing.
That bar is high, says Robert Stillman, a reproductive endocrinologist in Rockville, Md. Drug abuse, child abuse or psychotic behavior could be grounds to withhold treatment. "We're not in a position, nor should we be in a position, of deciding who's going to be good parents or how many children we want them to have," Stillman says.
Q: News reports have said Suleman didn't want to discard any of her frozen embryos. Did she have other options besides transferring them all at once?
A: "This is an avoidable consequence of fertility care," says Anne Lyerly, a Duke University obstetrician/gynecologist and bioethics researcher.
"If she couldn't bear to discard those embryos or to have them be in somebody else's family, they could have been transferred one at a time or two at a time." If that had been done, Lyerly says, Suleman might have decided to stop trying to have more children before using all of her embryos.
Sunday, February 22, 2009
Saturday, February 21, 2009
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