Monique Bonavita Bueno is an embryologist from Brazil who
visited Nigeria recently. In this interview with CHIOMA UMEHA, Bueno speaks on
s
What is the job of Embryologist?
Well we work with the garments, basically with the garments
of the patients. We do ovary stimulation and IVF treatment. So we work with
eggs and sperms and embryos. The sperm and eggs are placed into incubators and
examined carefully at intervals to ensure that fertilization and cell division
have taken place, after which the fertilized eggs are then known as embryos.
Two to five days after egg retrieval, embryos are ready to be placed in the
woman’s uterus.
What is the difference between sperm washing and sperm
freezing?
Sperm washing is the process in which individual sperms are
separated from the semen. Washed sperm is used in artificial insemination using
the intrauterine insemination (IUI) technique and in in vitro fertilization
(IVF).
Sperm washing involves removing any mucus and non-motile
sperm in the semen to improve the chances of fertilization and to extract
certain disease-carrying material in the semen. Sperm washing is a standard
procedure in infertility treatment. Sperm washing takes place in a laboratory
following sperm donation.
Sperm washing is done before sperm freezing. We take the
sample of a man’s (patient’s) sperm and wash it before freezing. So we need to
wash so will just keep the sperm to freeze.
How long can freezing last?
There is no limit for the freezing
What does Preimplantation of genetics diagnosis involve?
Preimplantation of genetics diagnosis (PGD) is a genetic
testing used to determine the embryos that carry a specific gene mutation
before the pregnancy occurs. While preimplantation genetics screening (PGS)
refers to removing one or more cells from an in vitro fertilization embryo to
test for chromosomal normalcy. PGS screens the embryo for normal chromosome
number. We can think of PGS as chromosome disorder screening on IVF embryos. So
PGS increase the chances for a healthy pregnancy.
What are the limitations?
There are no limitations, we have many good reasons to do
the PGD and PGS. Actually the main benefits of PGD are to prevent the
transmission of monogenic disorder by restoring the genetic quality of the
embryo while the PGS will steady the chromosomical quality of the embryo and
screen for equal embryo to be transferred. It would help in reducing the
miscarriage rate; it will increase the implantation rate and also the chances
of having a baby.
Who is qualified to do it?
Though anyone can undergo PGD and PGS, I will add that it is
common mainly among patients that have advanced in maternal age. Women aged 37
and above: any IVF patient aged 37 or above may benefit from PGS, provided that
they produce five or more embryos.
Patients in their mid-thirties are more likely to produce
abnormal embryos so they are more likely to do the PGS that will analyse and
identify abnormal chromosomal abnormality and identify an equal embryo to
transfer to her uterus.
Preimplantation genetic diagnosis can benefit any couple at
risk for passing on a genetic disease or condition.
The following is a list of the type of individuals who are
possible candidates for PGD are: Carriers of sex-linked genetic disorders;
carriers of single gene disorders; those with chromosomal disorders; women aged
35 and over. Others are: Women experiencing recurring pregnancy loss and women
with more than one failed fertility treatment.
PGD has also been used for the purpose of gender selection.
However, discarding embryos based only on gender
considerations is an ethical concern for many people.
What are the benefits of PGD?
The following are considered benefits of PGD: PGD can test
for more than 100 different genetic conditions.
The procedure is performed before implantation thus allowing
the couple to decide if they wish to continue with the pregnancy.
The procedure enables couples to pursue biological children
who might not have done so otherwise.
What are the concerns of PGD?
The following are considered concerns or disadvantages
associated with the use of PGD: Many people believe that because life begins at
conception, the destruction of an embryo is the destruction of a person.
While PGD helps reduce the chances of conceiving a child
with a genetic disorder, it cannot completely eliminate this risk. In some
cases, further testing is needed during pregnancy to ascertain if a genetic
factor is still possible.
Although genetically present, some diseases only generate
symptoms when carriers reach middle age. The probability of disorder
development should be a topic of discussion with the healthcare provider.
Keep in mind that preimplantation genetic diagnosis does not
replace the recommendation for prenatal testing.
What is egg bank and sperm bank?
Sperm bank or egg bank or cryo bank in general is a facility
that store human sperm, human eggs, garment in general from sperm to egg donors
to use by human or couple who need donor provider garments and to achieve the
pregnancy which they cannot using theirs.
Can you then define what fertility preservation is?
Fertility preservation is the process of saving eggs, sperm
or embryo or ovarian tissue before they go into fertility damaging treatment
like cancer treatment so the person can still use their garment to achieve
pregnancy in the future. So women who want to delay motherhood can also preserve
their eggs, so she is able to use her eggs to have her own biological child
when she is ready.
A woman’s egg was preserved at 30 and now she is 40. How
would you describe the success rate, how viable is it?
And as an experienced embryologist, you should be sure of
doing it in a perfect way so the patient can come at 30-years-old, then returns
when she is 40. If so, her egg will continue to be exactly the same quality.
How is the preservation done?
Currently we have a technique called cryopreservation, and vitrification.
Cryopreservation and vitrification are methods used for preserving human germ
cells. Thanks to them, germ cells may be preserved in our cryobank for as long
as several decades. The preservation period depends on the agreement with the
client.
The difference between cryopreservation and vitrification is
in the cell freezing rate.
Cryopreservation is a technique that utilises a special
medium to allow preservation in liquid nitrogen at a temperature of -196°C.
Vitrification is a modern technique that rapidly freezes
reproductive cells to a temperature of -196°C, literally within seconds. A
special medium containing cryoprotectants is used during the process to protect
the cells against damage.
Vitrification is rapid freezing of eggs or embryos. So it is
very quick with successful rate of eggs and embryos. The success is higher than
slow freezing that anything that was done before now.
