In vitro fertilization (IVF) is responsible for creating thousands of
happy families, but the latest research highlights some of the
potential long term risks of the procedure.
The role infertility treatments play in birth defect risk isn’t fully
understood, and whether it’s the in vitro fertilization (IVF)
procedures or infertility itself that bears the greatest influence
remains up for debate.
Researchers presenting at the American Academy of Pediatrics (AAP)
National Conference and Exhibition in New Orleans report that IVF
may significantly increase birth defect risk, especially in the heart,
eyes, reproductive organs and urinary systems, among children born
through the technique.
In their study, scientists at the University of California, Los Angeles
(UCLA) looked at birth defects among infants born both via IVF and
conceived through natural means in California, which has the country’s
highest rate of IVF use. They included babies born after IVF and other
assisted reproductive treatments such as couples’ use of
fertility-enhancing drugs and artificial insemination.
Among 4795 babies born after IVF and 46,025 infants who were
conceived naturally, 3,463 babies had congenital birth defects. Even
after controlling for factors that can affect such birth defects, such
as mother’s age, and race, which can influence rates of genetic and
environmentally driven developmental disorders, 9% of infants born after
IVF had birth defects compared to 6.6% of babies who were conceived
naturally. Overall, the babies born after IVF were 1.25 times more
likely to be born with abnormalities. The researchers did not find a
link between birth defects and other fertility treatments like
artificial insemination or ovulation induction.
It’s possible that the higher rate of abnormalities with IVF is due
in part to whatever was contributing to infertility in the first place,
say the researchers. But the fact that an increase was not seen among
babies conceived using artificial insemination or ovulation induction
suggests that process of IVF itself, in which eggs are removed from a
woman, fertilized in a dish with sperm and then allowed to develop into
embryos, which are transplanted back into the womb, is the primary
culprit.
“For parents considering in vitro fertilization or other forms of
assisted reproductive technology, it is important that they understand
and discuss with their doctor the potential risks of the procedure
before making a decision,” said lead study author Dr. Lorraine
Kelley-Quon, a general surgery resident at at Ronald Reagan UCLA Medical Center, in a statement.
An earlier study in the New England Journal of Medicine also
reported a link between fertility treatments and a higher risk of birth
defects, but risk varied greatly by procedure. In that study, IVF was
not associated with birth defects, but other procedures such as
intracytoplasmic sperm injection (ICSI) and ovulation stimulation
medications were. They also reported that frozen embryos created through
IVF were less likely to result in babies with birth defects than fresh
embryos.
Despite the fact that more than four million babies have been born
using IVF, and the first ones are just reaching reproductive age, it’s
clear that some of the long term effects of IVF and other assisted
reproductive techniques still aren’t well understood.
Even so, the American Society for Reproductive Medicine (ASRM) is
taking an important step regarding another infertility treatment by
announcing that egg freezing should no longer be considered an
“experimental” treatment for couples unable to conceive naturally. The
decision is based on a report developed an ASRM committee and the
Society for Assisted Reproductive Technology (SART). After reviewing
nearly 1,000 cases of egg freezing, the committee members found that the
chances of getting pregnant via IVF were comparable using both fresh
and frozen eggs. They also found no increases in birth defects,
chromosomal abnormalities and developmental disorders among babies born
using frozen eggs. In most cases, women take hormones to in order to
release several mature eggs at a time, and these are surgically
collected and fertilized as soon as possible. But because the number of
eggs generated with each such ovulation cycle varies, some women chose
to freeze eggs from a particularly successful cycle so they can be
fertilized at a later date.
“I think this will really allow so many more women greater options
for family building, which is terrific,” says lead study author Dr.
Samantha Pfeifer of the University of Pennsylvania. Successful IVF, for
example, requires an adequate supply of sperm to be available when a
woman’s eggs are retrieved, and sometimes that’s not possible. Freezing
eggs means the eggs can be thawed whenever that robust supply of sperm
is available. It’s also an option for couples who aren’t comfortable
freezing embryos, which some see as the earliest form of life. “Now they
have this as an option,” says Pfeifer.
Lifting the “experimental” classification for egg freezing could also
push insurers to cover the expensive procedure, which they currently do
not reimburse for infertility treatment (some cover egg freezing costs
for women being treated for reproductive cancers). “Insurance companies
should have coverage for it and I think more programs are going to be
offering this technique. It allows patients to have greater access to
the procedure,” says Pfeifer.
However, she warns that it’s too early to tell if the rate of
developmental anomalies among babies born from frozen eggs is similar to
children born from frozen embryos. Although it appears to be a safe
procedure, more long-term research is needed before it’s routinely used.
The ASRM is also not advising healthy women without infertility
problems to freeze their eggs for future use.
Source Link: http://healthland.time.com/2012/10/22/ivf-linked-to-more-birth-defects/
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