May 2008
P3
Rates of dementia appear to be lower
among women who drink wine than
those who consume other alcoholic beverages.
The authors of a recently-published study
reported 164 cases of dementia among 1,462
Swedish women over a 34-year period.
Analysis of participants’ drinking habits
found that total alcohol consumption did
not relate to the likelihood of developing
dementia, but drinking wine was associated
with a protective effect (hazard ratio .56
using a multivariate model). Consumption
of spirits, conversely, appeared to increase
the risk for dementia.
This contrast suggests that the protective
effects of wine could stem from a constituent
which is not found in other alcoholic
drinks, the study concludes. [Am J Epidemiol
2008 Mar 15;167(6):684-91]
Monday, February 2, 2009
Smoking during teen pregancy reduces birthweight
May 2008
P3
Teenagers who smoke while pregnant
are more likely to have low birthweight
(LBW) babies, a study from the
University of New South Wales in Sydney
has found.
Analysis of data from 25,828 births over
a 4-year period showed that the prevalence
of LBW among smoking teenage mothers
was 9.9 percent, compared to six percent
among their non-smoking counterparts.
The study found, however, that teenage
mothers who quit smoking during the
second half of pregnancy had babies with
normal rates of LBW.
“Health professionals need to target
smoking cessation at all contacts with
pregnant women who continue to smoke,”
the authors advise. [Med J Aust 2008 Apr
7;188(7):392-6]
P3
Teenagers who smoke while pregnant
are more likely to have low birthweight
(LBW) babies, a study from the
University of New South Wales in Sydney
has found.
Analysis of data from 25,828 births over
a 4-year period showed that the prevalence
of LBW among smoking teenage mothers
was 9.9 percent, compared to six percent
among their non-smoking counterparts.
The study found, however, that teenage
mothers who quit smoking during the
second half of pregnancy had babies with
normal rates of LBW.
“Health professionals need to target
smoking cessation at all contacts with
pregnant women who continue to smoke,”
the authors advise. [Med J Aust 2008 Apr
7;188(7):392-6]
On-site surgical facilities not essential for performing PCI
May 2008
P7
A new study suggests that percutane -
ous coronary intervention (PCI) can be safely performed at facilities where patients
must be transferred off-site in order
to undergo surgery in the event of complications
– a finding likely to change practice
guidelines.
PCI can lead to complications such as
cardiac muscle rupture and myocardial
perforation, and current guidelines recommend
these procedures only be undertaken
at centers where cardiac surgery can be
performed on-site.
“Off-site PCI centers can provide excellent
care to patients if the organization of
the program is thoughtfully developed,”
said Dr. Michael Kutcher of Wake Forest
University in Winston-Salem, North Carolina,
US.
Kutcher presented figures from the
National Cardiovascular Data Registry
(NCDR), comparing the outcomes of
299,132 consecutive PCI procedures performed
at 404 on-site centers against those
of 9,029 procedures performed at 61 offsite
centers.
“The risk-adjusted mortality rate at
off-site facilities was comparable to those
PCI centers that have cardiac surgery onsite,”
he said, stressing however, that these
findings should not be used to encourage
the widespread introduction of off-site
PCI facilities.
Procedural success rates, morbidity and
rates of emergency coronary artery bypass
grafting (CABG) were also comparable for
the two types of center.
As well as assessing procedural outcomes,
the NCDR data were used to gain
insights into the organization and logistics
of off-site PCI centers. The researchers
found that these centers typically had fewer
beds and a lower annual volume of procedures
compared to on-site centers, but had
dedicated staff and facilities and provided
24 hour coverage. Off-site centers were also
capable of providing timely transfer to surgical
facilities, in the event that surgical intervention
was necessary. All off-site centers
performed both primary and elective PCI,
and tended to treat a higher proportion of
patients who presented with ST-segment
elevation and non-ST-segment elevation
myocardial infarction than on-site centers.
Commenting on the study findings, Dr.
Stephan Windecker of the Swiss Cardiovascular
Center in Bern, Switzerland, referred
to results from the Swedish Coronary
Angiography and Angioplasty Registry,
which also demonstrated comparable outcomes
for on-site and off-site PCI facilities.
He explained that technological advances
have enabled many complications of PCI to
be treated by non-surgical means, and that
emergency CABG after PCI is becoming increasingly
rare.
“I think the present study should give
the impetus to update the present guidelines,”
concluded Windecker. The researchers
“should be congratulated for putting
an end to a controversy which is as long as
angioplasty itself.
P7
A new study suggests that percutane -
ous coronary intervention (PCI) can be safely performed at facilities where patients
must be transferred off-site in order
to undergo surgery in the event of complications
– a finding likely to change practice
guidelines.
PCI can lead to complications such as
cardiac muscle rupture and myocardial
perforation, and current guidelines recommend
these procedures only be undertaken
at centers where cardiac surgery can be
performed on-site.
“Off-site PCI centers can provide excellent
care to patients if the organization of
the program is thoughtfully developed,”
said Dr. Michael Kutcher of Wake Forest
University in Winston-Salem, North Carolina,
US.
Kutcher presented figures from the
National Cardiovascular Data Registry
(NCDR), comparing the outcomes of
299,132 consecutive PCI procedures performed
at 404 on-site centers against those
of 9,029 procedures performed at 61 offsite
centers.
“The risk-adjusted mortality rate at
off-site facilities was comparable to those
PCI centers that have cardiac surgery onsite,”
he said, stressing however, that these
findings should not be used to encourage
the widespread introduction of off-site
PCI facilities.
Procedural success rates, morbidity and
rates of emergency coronary artery bypass
grafting (CABG) were also comparable for
the two types of center.
As well as assessing procedural outcomes,
the NCDR data were used to gain
insights into the organization and logistics
of off-site PCI centers. The researchers
found that these centers typically had fewer
beds and a lower annual volume of procedures
compared to on-site centers, but had
dedicated staff and facilities and provided
24 hour coverage. Off-site centers were also
capable of providing timely transfer to surgical
facilities, in the event that surgical intervention
was necessary. All off-site centers
performed both primary and elective PCI,
and tended to treat a higher proportion of
patients who presented with ST-segment
elevation and non-ST-segment elevation
myocardial infarction than on-site centers.
Commenting on the study findings, Dr.
Stephan Windecker of the Swiss Cardiovascular
Center in Bern, Switzerland, referred
to results from the Swedish Coronary
Angiography and Angioplasty Registry,
which also demonstrated comparable outcomes
for on-site and off-site PCI facilities.
He explained that technological advances
have enabled many complications of PCI to
be treated by non-surgical means, and that
emergency CABG after PCI is becoming increasingly
rare.
“I think the present study should give
the impetus to update the present guidelines,”
concluded Windecker. The researchers
“should be congratulated for putting
an end to a controversy which is as long as
angioplasty itself.
Embryo transfer: Practice makes perfect
May 2008
SFV
Clinicians should routinely carry out a
“dummy run” before performing embryo
transfer, according to a leading
in- vitro fertilization (IVF) expert.
“A lot of people don’t do it because it
takes time and is costly to do a trial transfer
… but it’s well worth it,” said Dr. Bill Yee,
clinical professor of obstetrics and gynecology
at the University of California, Los
Angeles, and the University of California,
Irvine, US.
The ease of embryo transfer is a known
predictor for pregnancy, and success rates
are significantly lower among patients who
experience a “difficult” transfer. [Hum Reprod
2002;17:2632-5]
“Difficult transfers occur in about 10
percent of patients,” said Yee. “If you can
convert those 10 percent into easy transfers
then it will improve your success rate.”
Dummy transfers can be used to assess
key features of a patient’s anatomy, such as
the uterine depth and the direction of the cavity.
This process also enables identification of
cervical stenosis, acute utero-cervical angles,
and endocervical ridges and blockages – factors
which can complicate the transfer process.
Obtaining prior knowledge of these factors
can help clinicians to formulate an appropriate
strategy for the actual transfer, said Yee.
Once a potentially difficult transfer is
identified, clinicians can select the catheter
that will be best suited to the procedure and
decide whether to use ultrasonography for
guidance. Cervical dilatation can also be
planned in order to facilitate the actual transfer
process. Identification of abnormalities
during a trial transfer can prompt further
investigation with hysteroscopy or sonohystography
and, in cases of severe blockage, reconstruction
of the endocervical canal might
be indicated.
In Yee’s practice two trial runs are performed
before undertaking embryo transfer.
The first is performed in advance; the second
immediately prior to the actual procedure.
“If you find it to be difficult then it gives
you time to do something to the endocervical
canal,” he explained, adding that less expensive
catheters can be used for the dummy
runs.
The benefits of performing dummy transfers
have been known for some time. Data
from a randomized controlled trial comprising
335 embryo transfers demonstrated that
the pregnancy rate was 22.8 percent among
those who had undergone a trial transfer,
compared to 13.1 percent among those who
had not. [Fertil Steril 1990;54:678-81]
Yet despite these findings, Yee believes
that this technique has not yet become routine
practice. “In the United States we found that
about 60 percent of clinicians will do a trial
transfer,” he said.
Yee also stressed the importance of embryo
transfer within the overall process of
IVF, and urged clinicians to give greater attention
to this stage.
“I think that many programs see this
as equivalent to artificial insemination and
therefore little training is actually applied to
this procedure. I still see places where whoever’s
free will do the transfer. You have worked
so hard to develop these embryos and blastocysts
and the final transfer is critical to IVF
success, yet this procedure is often left to the
least experienced clinician in the practice,”
Yee concluded.
SFV
Clinicians should routinely carry out a
“dummy run” before performing embryo
transfer, according to a leading
in- vitro fertilization (IVF) expert.
“A lot of people don’t do it because it
takes time and is costly to do a trial transfer
… but it’s well worth it,” said Dr. Bill Yee,
clinical professor of obstetrics and gynecology
at the University of California, Los
Angeles, and the University of California,
Irvine, US.
The ease of embryo transfer is a known
predictor for pregnancy, and success rates
are significantly lower among patients who
experience a “difficult” transfer. [Hum Reprod
2002;17:2632-5]
“Difficult transfers occur in about 10
percent of patients,” said Yee. “If you can
convert those 10 percent into easy transfers
then it will improve your success rate.”
Dummy transfers can be used to assess
key features of a patient’s anatomy, such as
the uterine depth and the direction of the cavity.
This process also enables identification of
cervical stenosis, acute utero-cervical angles,
and endocervical ridges and blockages – factors
which can complicate the transfer process.
Obtaining prior knowledge of these factors
can help clinicians to formulate an appropriate
strategy for the actual transfer, said Yee.
Once a potentially difficult transfer is
identified, clinicians can select the catheter
that will be best suited to the procedure and
decide whether to use ultrasonography for
guidance. Cervical dilatation can also be
planned in order to facilitate the actual transfer
process. Identification of abnormalities
during a trial transfer can prompt further
investigation with hysteroscopy or sonohystography
and, in cases of severe blockage, reconstruction
of the endocervical canal might
be indicated.
In Yee’s practice two trial runs are performed
before undertaking embryo transfer.
The first is performed in advance; the second
immediately prior to the actual procedure.
“If you find it to be difficult then it gives
you time to do something to the endocervical
canal,” he explained, adding that less expensive
catheters can be used for the dummy
runs.
The benefits of performing dummy transfers
have been known for some time. Data
from a randomized controlled trial comprising
335 embryo transfers demonstrated that
the pregnancy rate was 22.8 percent among
those who had undergone a trial transfer,
compared to 13.1 percent among those who
had not. [Fertil Steril 1990;54:678-81]
Yet despite these findings, Yee believes
that this technique has not yet become routine
practice. “In the United States we found that
about 60 percent of clinicians will do a trial
transfer,” he said.
Yee also stressed the importance of embryo
transfer within the overall process of
IVF, and urged clinicians to give greater attention
to this stage.
“I think that many programs see this
as equivalent to artificial insemination and
therefore little training is actually applied to
this procedure. I still see places where whoever’s
free will do the transfer. You have worked
so hard to develop these embryos and blastocysts
and the final transfer is critical to IVF
success, yet this procedure is often left to the
least experienced clinician in the practice,”
Yee concluded.
New techniques for embryo freezing
May 2008
Vitrification – the rapid freezing of embryos
in liquid nitrogen – could supersede
current cryopreservation methods, an expert
has advised.
“I think that vitrification of embryos will
one day become routine practice instead of
conventional slow freezing,” said Professor
Shee-Uan Chen of the National Taiwan University
Hospital in Taipei.
The majority of in-vitro fertilization (IVF)
centers in South East Asia currently preserve
embryos and blastocysts using slow
freezing, which takes around 3 hours. Vitrification,
whereby embryos are directly solidified
into a glass-like state, is more costeffective
and can take as little as 6 minutes,
but has prompted safety concerns regarding
the high concentrations of cryoprotectants
involved.
Chen says, however, that sufficient data
is now accumulating to support the widespread
use of vitrification. The technique is
already being adopted at his center, where
10 babies have been born from vitrified embryos,
to date.
A study published last year demonstrated
an 89 percent survival rate among vitrified
zygotes and a subsequent pregnancy
rate of 37 percent – three times higher than
that achieved using slow frozen cells. [Reprod
Biomed Online 2007 14(3):288-93]
“Both slow freezing and vitrification are
highly effective for pronuclear, early-stage
and blastocyst embryos, but vitrification
is time-saving and also appears to have a
higher survival rate,” said Chen. He added
that toxicity to the embryo can be reduced
by using aseptic liquid nitrogen and lowering
the concentrations of cryoprotectants.
The apparent superiority of vitrification
was also demonstrated by a recent metaanalysis
which found that post-thawing
survival rates were significantly higher
for vitrified blastocysts and cleavage stage
embryos than for those preserved by slow
freezing [Fertil Steril 2007, online 1 November].
Only four studies were eligible for the
analysis, however, and further trials are
needed to provide an assessment of pregnancy
rates.
Advances in cryopreservation have
made storing surplus embryos an increasingly
common practice. Successfully finetuning
these techniques can help to reduce
embryo wastage, and thereby maximize the
benefits of an IVF cycle.
“The trend is moving towards vitrification,”
added Dr. Kwang-Ryul Cha of the
Cha Research Institute in Seoul, where some
50 babies have been successfully born from
vitrified embryos. Cha is also confident that
this technique will one day replace conventional
embryo freezing techniques. “We need
more time to accumulate the data but I think
it’s not a problem,” he concluded. - DB
Vitrification – the rapid freezing of embryos
in liquid nitrogen – could supersede
current cryopreservation methods, an expert
has advised.
“I think that vitrification of embryos will
one day become routine practice instead of
conventional slow freezing,” said Professor
Shee-Uan Chen of the National Taiwan University
Hospital in Taipei.
The majority of in-vitro fertilization (IVF)
centers in South East Asia currently preserve
embryos and blastocysts using slow
freezing, which takes around 3 hours. Vitrification,
whereby embryos are directly solidified
into a glass-like state, is more costeffective
and can take as little as 6 minutes,
but has prompted safety concerns regarding
the high concentrations of cryoprotectants
involved.
Chen says, however, that sufficient data
is now accumulating to support the widespread
use of vitrification. The technique is
already being adopted at his center, where
10 babies have been born from vitrified embryos,
to date.
A study published last year demonstrated
an 89 percent survival rate among vitrified
zygotes and a subsequent pregnancy
rate of 37 percent – three times higher than
that achieved using slow frozen cells. [Reprod
Biomed Online 2007 14(3):288-93]
“Both slow freezing and vitrification are
highly effective for pronuclear, early-stage
and blastocyst embryos, but vitrification
is time-saving and also appears to have a
higher survival rate,” said Chen. He added
that toxicity to the embryo can be reduced
by using aseptic liquid nitrogen and lowering
the concentrations of cryoprotectants.
The apparent superiority of vitrification
was also demonstrated by a recent metaanalysis
which found that post-thawing
survival rates were significantly higher
for vitrified blastocysts and cleavage stage
embryos than for those preserved by slow
freezing [Fertil Steril 2007, online 1 November].
Only four studies were eligible for the
analysis, however, and further trials are
needed to provide an assessment of pregnancy
rates.
Advances in cryopreservation have
made storing surplus embryos an increasingly
common practice. Successfully finetuning
these techniques can help to reduce
embryo wastage, and thereby maximize the
benefits of an IVF cycle.
“The trend is moving towards vitrification,”
added Dr. Kwang-Ryul Cha of the
Cha Research Institute in Seoul, where some
50 babies have been successfully born from
vitrified embryos. Cha is also confident that
this technique will one day replace conventional
embryo freezing techniques. “We need
more time to accumulate the data but I think
it’s not a problem,” he concluded. - DB
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