Sperm Collection and Preparation
On the day of egg collection, the husband gives a
sperm sample. The semen specimen should be obtained following a 3-4 day
abstinence from sexual activity and masturbation is the preferred method of
collection. A shorter or longer period of time or the use of a different method
of collection may affect semen parameters. After collection the semen sample is
delivered to the lab where it is properly prepared for IVF. The purpose of the
preparation is to isolate the motile spermatozoa from other elements of the
semen and activate them in order to be capable to fertilize the mature oocytes.
It should be noticed that masturbation, especially
at the clinic, is sometimes difficult and stressful for men on the day of egg
collection. Therefore men could bring the semen sample from home or can freeze
a sample several days before the day of oocyte retrieval (fresh samples are
always preferred). In cases of men with azoospermia, spermatozoa are retrieved
directly from the testis (surgical sperm retrieval).
Egg Retrieval
The ability to collect mature eggs from a woman's
ovaries for fertilization outside of the body has revolutionized fertility
treatment. Originally developed as a way to help women whose fallopian tubes
were irreparably blocked, IVF now allows couples who suffer from a wide range
of fertility problems to successfully conceive. In vitro fertilization begins
with ovulation induction, a process of stimulating and monitoring the ovaries.
Once it is determined that the ovarian follicles are the right size and the
eggs ready to be collected, a dose of human chorionic gonadotropin (hCG) is
administered to trigger the final maturation process and egg retrieval will
take place approximately 36 hours later. Prior to the procedure, anesthesia
will be given. In most cases, egg retrieval is performed under moderate
sedation (aka MAC), allowing the patient to be asleep for the procedure. The
actual technique used to collect eggs for in vitro fertilization is known as an
ultrasound-guided transvaginal aspiration.
While an ultrasound probe is used to provide a
visual image of the ovary and the surrounding structures, a very fine needle is
inserted through the upper wall of the vagina and into the ovary. Through
magnification of the ultrasound image, the physician can locate the individual
follicles that contain mature eggs and apply gentle suction to remove the
contents of each one, which is known as aspiration. The fluid and egg from each
follicle are collected into an individual container, which will then be taken
to the lab for examination and preparation for fertilization. The procedure is
performed on both ovaries, usually taking between 10 and 15 minutes to
complete. Once the egg retrieval process is finished, the patient will remain
under observation for one or two hours before being sent home. Patients may
experience some discomfort after egg retrieval and are encouraged to rest as
much as possible. Mild soreness, cramping, and light spotting are normal.
Vigorous exercise and other strenuous activities
should be avoided. Specific instructions will be provided prior to the
procedure and should be followed carefully. Progesterone, a hormone that would
normally be released by the follicle after ovulation, is vital to the support
of early pregnancy. Because aspiration of the follicles can interrupt the
normal hormonal process and prevent adequate amounts of progesterone from being
produced, the patient will generally be given supplemental progesterone from
the time of egg retrieval through the end of the cycle.
The whole process is performed under mild sedation
with a recovery period of approximately an hour. However, it is important to
notice that for safety reasons, women scheduled for egg retrieval must be at
the clinic at least 30 minutes before the procedure in order to have a
cardiograph and talk to the anesthesiologist about allergies, any medication
they are taking and any other health problems they may have. Last but not
least, women programmed for this procedure shouldn’t eat or drink anything from
the previous night.
Oocyte Fertilization
Several hours after egg retrieval and semen
preparation, fertilization occurs. More specifically at a conventional IVF
cycle the mature oocytes are placed in 4-well dishes of culture medium
containing processed sperm. One of the spermatozoa will penetrate and fertilize
the oocyte. In cases of severe male infertility, other laboratory techniques
are required following egg retrieval. Fertilization may be assisted by
intracytoplasmic sperm injection (ICSI), a micromanipulation technique which
involves the injection of a sperm directly into the egg. The eggs are then
incubated in the lab overnight.
The next morning, 16-18 hours after the time of
fertilization, fertilization check is performed by the embryologists. The first
signs of normal fertilization are shown by the presence of two pronuclei (small
round structures) within the egg. The fertilization rate is usually between 50
and 100%. The maturity of the oocytes, semen parameters, handling procedures
and culture systems are some factors that are responsible for the variance in
the fertilization rate.
Embryo culture, selection and transfer
The earliest stages of human development, until day
five or six after fertilization, normally occur in the woman’s fallopian tube.
However, after in vitro fertilization (IVF), much of this period of early
development occurs in the laboratory. The conditions under which the embryos
are “cultured” have been carefully formulated to provide an environment that as
closely as possible that of the fallopian tube. Recently, commercially prepared
culture media have become available. These media support embryo development in
the laboratory for up to six days. By allowing the embryo to reach the
blastocyst stage, we can make a more stringent selection of those to be transferred
during an IVF cycle; as a result, these systems may be preferable for patients
who would prefer or benefit from a one- or two-embryo transfer.
Once the embryos have been created in the
laboratory, they are placed into the uterus. At this point, in order for
pregnancy to occur, an embryo must implant into the uterine lining. For many
patients, the two-week wait between the embryo transfer procedure and the
initial pregnancy test is the most difficult stage of the process. While the
embryos are developing in the laboratory, they are monitored for rate of
growth, size, form, and signs of irregularity. Based on this data, the embryos
are graded by quality, which helps us to estimate which are most likely to
successfully implant and continue to develop. Typically, the embryos of the
highest grade are selected for the first IVF transfer. Embryos with significant
abnormalities are not suitable for transfer and will be discarded. In most
instances, no more than two or three embryos will be transferred during any
given IVF cycle. This number allows the best chances for implantation while
still keeping the risk of a multiple pregnancy to a minimum. In some cases, depending
on age and other factors, our physicians recommend electing a single embryo
transfer. Any additional embryos that are created will be cryopreserved for
later transfer. The embryo transfer procedure will be scheduled for three to
five days after the egg retrieval. In IVF cycles where frozen embryos are to be
used, the patient will be closely monitored via ultrasound and the embryos will
be placed about two days after ovulation takes place.
This stage of in vitro fertilization treatment
involves threading a thin catheter through the opening in the cervix, through
which the embryos are gently deposited into the uterus. There is very little
discomfort during this part of treatment and anesthesia is not necessary. After
the transfer procedure, our IVF patients are advised to take it easy for the
next few days. Physical activity should be limited and strenuous exercise
should be avoided. Although there is little that can be done at this point that
will affect the chances of successful implantation, eating well, getting enough
sleep, and minimizing stress will go a long way toward the health and wellbeing
of the patient. The process of implantation is complex and unpredictable.
First, the embryo must escape, or hatch, from the zona Pellucida. Even if the
embryos are transferred on day three, this will not occur until after the
embryos have reached the blastocyst stage on day five or six. Once an embryo
has hatched, it must attach to the endometrium, or uterine lining, and
gradually become imbedded in it. Once an embryo has completed this process,
pregnancy is achieved and the in vitro fertilization cycle is a success.
Approximately fourteen days after the embryo
transfer procedure, a blood test will be conducted to measure the amount of
human chorionic gonadotropin (HCG) in the patient's system. This hormone is
released only after implantation and is an accurate indicator of pregnancy.
However, because HCG is sometimes used during the ovulation induction process
to trigger the final maturation of the oocytes, small amounts may exist even if
the patient is not pregnant. For this reason, at-home pregnancy tests that
detect the presence of HCG but do not measure the quantity are not considered
accurate for women undergoing in vitro fertilization. Elevated levels of HCG
indicate that implantation has occurred and the patient is pregnant. If
pregnancy is detected, the patient will then undergo an ultrasound examination
to confirm the findings, determine how many embryos have implanted, and ensure
that everything is progressing normally.
If pregnancy has occurred, progesterone treatments
will be continued for a period of time and then be gradually reduced as the
patient's body takes over normal hormone production. The patient will continue
to visit our IVF Centre for blood work and ultrasounds during the early weeks
of pregnancy to ensure that everything is proceeding as it should. Once we are
able to detect the fetal heartbeat, the patient will be referred to an OB-GYN
(if she does not have one already), who will handle the remainder of the
patient's prenatal care. A high-risk obstetrician is only necessary if certain
medical problems are a factor.
If pregnancy has not occurred, progesterone
supplements will be ceased and the cycle will come to an end. If the couple has
opted to try another in vitro fertilization cycle, we may recommend waiting one
or even two complete menstrual cycles before resuming treatment. This allows
the body to rest and gives us a chance to examine our treatment strategy and
possibly change our approach in future cycles. In subsequent IVF cycles, the
ovulation induction phase may not be necessary if frozen embryos are available
for transfer.
Complications & Risk Factors after Embryo Transfer
Assisted reproduction technique (ART) is an efficacious
treatment in sub fertile couples. So far little attention has been paid to the
safety of ART, i.e. to its adverse events and complications; the consensus
meeting on Risks and Complications in ART.
Multiple
pregnancies
If 25% of all pregnancies after IVF/ICSI are
twin pregnancies, 40% of all babies born after ART are born as part of a twin
pair. Many physicians and patient couples underestimate the negative
consequences of twin pregnancies. Perinatal as well as maternal mortality and
morbidity are increased in multiple pregnancies as compared with singleton Pregnancies
due to a higher rate of prematurity and low birth weights in the children; and
due to pregnancy complications in the mothers. Furthermore, parents of multiple
births have more stress, and siblings of multiples are more likely to have
behavior problems.
Long-term
effects of ART on women
Hormonal and reproductive factors are involved
in the etiology of breast cancer and cancers of the female genital tract.
Therefore, the effect of fertility drugs on the risk of these
Cancers has been investigated. Many studies have
not been able to reach solid conclusions due to low statistical power, lack of
control for important confounders (such as cause of sub fertility and parity)
and short duration of follow-up.
Effects
of ART on offspring
Much concern has been expressed about the health
of children born after ART. In particular, the risk of boys born to couples
with male factor sub fertility has drawn attention, since in a substantial
number of male factor sub fertility cases, a genetic cause can be suspected.
Patient
selection and counseling for eSET (elective single-embryo transfer)
It was agreed that the essential aim of IVF/ICSI
is the birth of one single healthy child, with a twin pregnancy being regarded
as a complication. The chances of having a single healthy child after eSET have
increased, and equal the spontaneous pregnancy rate in a normally fertile
couple.
Women who can get pregnant without fertility
drugs or medical procedures usually have only one baby. Women who need
fertility treatment are at higher risk to get pregnant with twins, and rarely
with triplets or more. This is called multiple gestations. Multiple gestations
can increase the risk of pregnancy for the mother and for all the babies. Multiple
gestations are risky for the babies. Because there are too many babies in the
womb, you may have a miscarriage. A miscarriage occurs when your pregnancy ends
without the birth of any infants that can survive, before the 20th week
of pregnancy. Or you could have a premature delivery when the babies may be
born too early (but after 20 weeks of pregnancy) and have problems with lungs,
stomach, or intestinal tract. They may have bleeding in the brain, which can
cause problems with the baby's brain, nervous system, and hamper its
development. If the babies are born very early, they will probably be very
small and may even die. Twins, triplets,
and other multiples are more likely to have problems with their brain
development and nerves if they are born early. One of the more common problems
is cerebral palsy, a condition that affects movement. Other problems associated
with multiple births may not present for many years after delivery
Embryo transfer and elective single embryo transfer
have become popular topics as more couples turn to fertility treatments to
conceive. Our Fertility doctor takes your age and in vitro fertilization (IVF)
prognosis into account when performing embryo transfer. Pahlajani Test Tube
Baby has a clear guidelines offer you the best chances for a healthy pregnancy
and delivery. Do you have a good prognosis for IVF? A good, or favorable, IVF
prognosis applies to women who:
» Are in
their first IVF cycle
» Have
healthy embryos or multiple frozen embryos
» Have
already had success with IVF
If you are under 35, and have a favorable
prognosis for IVF, you are more likely to conceive with a single embryo
transfer. If you're over 35 and have a good IVF prognosis, our doctor may
prefer to transfer more than one embryo.
» Under 35:
1-2 embryos
» 35 to 37:
2 embryos
» 38 to 40:
2 to 3 embryos
» 41 to 42:
3 to 5 embryos
Becoming pregnant with multiples increases the
risk of complications for you and your babies. Single embryo transfer can help
you avoid these risks. The most common complications associated with multiples
are increased rates of preterm labor and preterm delivery. Preterm delivery can
cause a host of problems for the infant, including:
»
Respiratory, growth, and digestive problems
» Long-term
learning and developmental difficulties
» Low birth
weight
Complications for mom are also increased with
multiple gestations. Here are some of the increased health risks for moms of
multiples:
» C-section
» Emotional
stress
»
Gestational diabetes
» High blood
pressure and preeclampsia
» Increased
cost for medical care
» Increased
risk of miscarriage
This is why doctors prefer single embryo
transfer, or transferring a lower number of embryos during IVF, when possible.
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