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Fertility treatments
Once
infertility has been diagnosed, a number of options are
available, depending on the cause of the
problem. |
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Fertility drugs
Fertility drugs are often the first treatment for women who
aren't ovulating |
Fertility drugs are often the first treatment for women who
aren't ovulating. They work in the same way as the body's own
hormones, triggering the ovaries to release eggs.
This method, known as ovulation induction, can sometimes lead to
conception after a few months without further intervention.
Possible side effects include premenstrual symptoms such as
nausea, headaches and weight gain.
Such drugs are also used as part of other more complicated
assisted reproduction treatments, such as in vitro fertilisation and
intrauterine insemination (see below). Other drugs - to help control
the menstrual cycle or thicken the lining of the womb to prepare it
for pregnancy, for example - may also be used. These can also cause
side effects, such as hot flushes, headaches, nausea and swollen
breasts.
Intrauterine insemination (IUI)
What
is it? Intrauterine insemination, also known as artificial
insemination, involves inserting sperm into the womb at the time of
ovulation using a catheter (a very fine needle or probe). The woman
may need to take fertility drugs to stimulate egg production. The
sperm used may be her partner's or donated.
Used to treat: unexplained infertility,
premature ejaculation, erection difficulties.
Success
rate: ten to 15 per cent per cycle.
In vitro fertilisation (IVF)
What is
it? Eggs and sperm are collected and fertilised in the
laboratory before the resulting embryo is transferred to the womb.
The woman takes fertility drugs to stimulate the production of eggs.
Once these are mature, they're collected by ultrasound guidance. The
man produces a sperm sample, which is prepared before being put with
the eggs in a Petri dish and left for a few days to see if
fertilisation takes place. A resulting healthy embryo is placed in
the womb using a catheter (a very fine needle or probe). Any
remaining embryos that are suitable for freezing may be stored for
future use. The sperm and/or eggs used may be the couple's own or donated.
Why
it's used: to treat unexplained infertility, blocked
fallopian tubes, endometriosis, PCOS.
Success
rate: about 25 per cent per cycle.
Intracytoplasmic sperm injection
(ICSI)
What is it? A single sperm is
injected into the cytoplasm or centre of a single egg. This is then
transferred to the womb using the same process as IVF.
Why it's used: to treat male factor
infertility, such as low sperm count or poor motility (mobility or
movement) or abnormally shaped sperm. ICSI may also be used
following previous unsuccessful attempts at fertilisation using IVF
and when sperm has been retrieved directly from the epididymis or
the testicles (see 'Sperm extraction', below).
Success
rate: as for IVF, about 25 per cent per cycle, sometimes
more.
Gamete intrafallopian transfer
(GIFT)
What is it? Gametes - eggs and
sperm - are collected as for IVF. Instead of mixing sperm and eggs
together in the laboratory, they're immediately transferred to one
of the woman's fallopian tubes so fertilisation takes place inside
the body. GIFT is an unlicensed treatment, which means it doesn't
have to take place in a clinic licensed by the HFEA.
Why
it's used: unexplained infertility.
Success
rate: about 25 per cent per cycle.
Sperm extraction
What is it? A small operation that removes sperm from the epididymis (the tube
where sperm mature in the man's body) or the testicles (where sperm
cells are made) for use in ICSI or another treatment. There are
several different methods of sperm extraction:
- PESA
(percutaneous epididymal sperm aspiration) involves guiding a small
needle into the epididymis to draw out fluid containing sperm.
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TESE (testicular sperm extraction) uses the same method to remove
tissue from the testes.
- MESA (microsurgical sperm aspiration)
uses a small needle to extract mature sperm from the
epididymis.
Why it's used: when a man can't
produce sperm - for example, after a vasectomy or failed
reversal.
Success rate: when used in ICSI, about
25 per cent per cycle.
Embryo freezing
What is it? The HFEA stipulates that (with certain strict exceptions) only two
embryos may be transferred to the womb at a time in fertility
treatments. This is under review and may be reduced to one embryo
due to the risk of pregnancy complications, and of multiple and
premature births. However, because IVF often creates more embryos
than can be transferred in a single cycle, most clinics will freeze
any remaining healthy embryos for use in future IVF treatments, with
the patients' consent.
Why
it's used: to avoid the need for further fresh IVF cycles
involving invasive processes of egg stimulation and collection.
Success rate: normally only 60 per cent of
embryos survive the freeze/thaw process and those that do survive
have a lower rate of implantation and so a lower pregnancy rate than
fresh embryos.
Clinics are increasingly using two newer techniques that may
enhance the chances of pregnancy in some patients.
Blastocyst transfer
If during previous IVF
attempts, the embryos fail to implant in the womb, the doctor may
suggest a blastocyst transfer. The embryo is allowed to develop for
five or six days before being transferred to the womb. Because the
embryo is more developed and transfer occurs closer to the time that
implantation would occur naturally, the pregnancy rate is usually
higher. However, some embryos will die in the laboratory, so the
number of embryos available for transfer and freezing will be fewer.
For this reason, it's generally only offered to women who produce a
large number of good quality embryos.
Assisted hatching
Before attaching itself to
the wall of the womb, an embryo has to break out (hatch) from a
gel-like membrane known as the zona pellucida. This membrane can be
tough or thickened and some fertility experts think it may impede
implantation of the embryo in the womb. To help the embryo break
through, the embryologist may make a tiny hole in the membrane
before it's transferred to help the hatching process.
Pre-implantation genetic diagnosis
(PGD)
What is it? PGD involves checking
the genes of embryos aged between two and five days, created by IVF
for genetic diseases such as haemophilia and cystic
fibrosis, as well as for some inherited diseases of later life
such as breast, ovarian and bowel
cancer. Disease-free embryos may then be transferred to the
womb.
When it's used: if a couple has a child
with a genetic disease and is at risk of having another; if there
have been several terminations because a genetic disorder was
diagnosed; if there's a strong family history of breast, bowel or
ovarian cancer.
Pre-implantation genetic screening
(PGS)
What is it? PGS (sometimes called
aneuploidy screening) involves checking IVF embryos to ensure they
have the correct number of chromosomes, and that these are
normal.
When it's used: if parents are older,
around 45 years, with a high risk of having a baby with chromosome
disorder such as Down's
syndrome or if the mother has a history of recurrent
miscarriages. Normal cells contain 23 pairs of chromosomes, making a
total of 46 chromosomes. PGS involves screening embryos produced by
IVF to ensure they have this number. This avoids embryos with the
wrong number of chromosomes being transferred to the womb. In Down's
syndrome, for example, there are three copies of the number 21
chromosome instead of the usual two.
Watch
Dr Simon Fishel talking about embryo screening and 'designer
babies'.
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