- Abandoned Cycle - In IVF, where a treatment cycle
is cancelled after commencing administration of drugs but before
embryo transfer.
- Adjusted Live Birth Rate - The live birth rate
(number of births rate for every 100 treatment cycles) once it has
been adjusted to take account of the different types of patients
which the clinic treated during the year.
- Assisted hatching - The mechanical, chemical or laser
breaching of the gelatinous coating of the eggs.
- Autosomal - Pertaining to any chromosome that
occurs in the nucleus, except for the sex chromosomes.
- Autosomal Dominant Disorders &endash; Disorders where
inheritance of a mutation from one parent only (or arising anew
during egg or sperm formation) can be sufficient for the person to
be affected. Important dominant disorders in the UK include
familial hypercholesterolaemia, Huntington's Disease, adult
polycystic kidney disease and familial adenomatous polyposis coli
(colon cancer).
- Autosomal Recessive Disorders &endash; Disorders, where for a
person to be affected, a mutation has to be inherited from both
parents. Such parents are usually unaffected carriers because they
only have a single copy of the mutant gene. Recessive disorders
commonly have onset in childhood and include cystic fibrosis,
sickle cell disease and thalassaemia.
- Cervical Mucus - The secretions surrounding the
cervical canal. The amount and texture change during ovulation to
allow sperm penetration.
- Chromosome - Small bodies within the nucleus of
every cell in the body. They contain the genes.
- Clinical Pregnancy - Ultrasound evidence of a
fetal heart.
- Clinical Pregnancy Rate - This is calculated as a
proportion of pregnancies with beating heart for every 100
treatment cycles commenced.
- Cloning - The production of genetically identical
(sharing the same nuclear gene set) individuals.
- Clones - Organisms that are genetically identical
(share the same nuclear gene set) to each other.
- Congenital - malformations, deformities, diseases etc.
are those which are either present at birth, or which, being
transmitted direct from the parents, show themselves soon after
birth.
- Congenital Abnormalities - Deformities or diseases
which are either present at birth or show themselves soon after
birth.
- Consent - acceptance of the procedures involved in
donation. A donor must give consent before any of the procedures
begin. Before she gives consent, a clinic must have given her
adequate information and offered counselling. Consent is given by
completing and signing a form supplied by the HFEA to the clinic.
This consent to the use and storage of eggs and embryos made from
those eggs is called 'informed consent'. Consent to a medical
procedure, such as egg collection is called 'valid consent'.
Consent can be changed - it may be withdrawn or varied at any time
unless the embryo concerned has already been used.
- Counselling - All licensed clinics are required to
offer patients counselling. Such counselling aims to enable the
patient to understand the implications of treatment, to give
emotional support and to help the patient cope with the
consequences of treatment.
- Cryopreservation - The freezing of oocytes,
spermatozoa or embryos and their storage in liquid nitrogen.
- Cystic Fibrosis - A disorder of the
mucus-secreting glands of the lungs, the pancreas, the mouth, and
the gastro-intestinal tract. The commonest serious genetic disease
in Caucasian children.
- Cytoplasm - The material between the nucleus and
the cell surface.
- Directions - The HFE Act allows the HFEA to impose
additional conditions on licensed activities. These Directions
cover areas where primary legislation would be inappropriate
because of the need for flexibility. Directions can be applied to
an individual clinic or generally.
- Donor - the woman who gives eggs to help another
woman become pregnant or for use in research.
- Donor Insemination (DI) - The insemination of donor
sperm into (DI) the vagina, the cervix or the womb itself.
- Drugs - which may be used in IVF treatment
- Buserelin - is a hormone suppressant which is given by nasal
spray or a daily injection. Buserelin suppresses the activity of a
small gland in the brain called the pituitary gland which normally
stimulates the ovaries to produce eggs. The ovaries can then be
stimulated artificially.
- HCG - Human Chorionic Gonadotrophin (may be called
Gonadotraphon LH, Pregnyl or Profasi) is given by injection about
34-36 hours before egg collection. It helps to ripen the eggs
within the follicles.
- HMG - Human Menopausal Gonadotrophin (may be called Pergonal
or Humegon) stimulates the development of egg follicles.
- FSH - Follicle Stimulating Hormone (may be called Metrodin)
can be given also to stimulate egg follicles.
- Egg Collection - Procedure by which eggs are
collected from the woman's ovaries by using an ultrasound guided
needle or by using a laparoscope (an instrument for looking into
the abdomen) and a needle. Also known as egg retrieval.
- Embryo - A fertilised egg up to eight weeks of
development. At two weeks it is approximately 1-1.5mm in diameter.
- Embryologist - A scientist who creates, cultures
and studies embryos in a clinical or research laboratory.
- Embryo Biopsy &endash; Removal and examination of one or more
cells from a developing embryo for diagnostic purposes.
- Embryo Freezing - Embryos not required for
treatment in a cycle can be frozen and stored for future use.
Freezing is also known as cryopreservation.
- Embryo Storage - The storage of one or more frozen
embryos for future use.
- Embryo Transfer - Transfer of one or more embryos to the
uterus.
- Endometriosis - A female condition in which
endometrial cells, which normally line the uterus, implant around
the outside of the uterus and/or ovaries, causing internal
bleeding, pain and reduced fertility.
-
- Epididymis - Coiled tubing outside the testicles which store
sperm.
- Fallopian Tube(s) - The tubes between the ovaries
and the uterus. After release of the egg from one of the ovaries,
the tube transports the egg to the uterus.
- Female Factor - This term covers any reason why a
woman is infertile, such as ovulation failure or damage to the
fallopian tubes.
- Foetus - The term used for an embryo after the
eighth week of development until birth.
- Follicle(s) - A small sac in the ovary in which the egg
develops.
- Gamete - The male sperm or the female egg.
- Gamete Intra Fallopian Transfer (GIFT) - A
procedure in which eggs are retrieved from the woman, mixed with
sperm and immediately replaced in one or other of the woman's
fallopian tubes so that they fertilise inside the body.
- Genetic Counselling &endash; A process by which information is
imparted to those affected by, or at risk of a genetic disorder.
It includes information on the nature of the disorder, the size
and extent of genetic risks, the options, including genetic
testing, that may help clarify the risks, and the available
preventative, supportive and therapeutic measures. In the context
of genetic testing it may include responding to the concerns of
individuals referred and their families, discussing the
consequences of a test, and help to choose the optimal decision
for themselves, but not determining a particular course of action.
- Genetic Testing &endash; Testing to detect the presence or
absence of, or change in, a particular gene or chromosome.
- Gonadotrophins - Drugs used to stimulate the ovaries similar
in composition to natural follicle stimulating hormone (FSH)
produced by the pituitary gland.
- Hamster Test (HEPT) - A test of the fertilising ability of
human sperm by observing their penetration into the hamster egg.
- Hepatitis - Refers to infection with one of the
hepatitis viruses which causes acute or chronic inflammation of
the liver cells.
-
- HFEA - Human Fertilisation and Embryology
Authority
- Hormone - hormones are natural chemical substances
produced by the body some of which control the development and
release of the egg from the ovary during each menstrual cycle.
Natural and synthetic preparations of those hormones are used to
increase the number of eggs produced in a cycle.
- Intra Cytoplasmic Sperm Injection (ICSI) - A
micromanipulation technique. A variation of IVF treatment where a
single sperm is injected into the inner cellular structure of the
egg. This technique is used for couples in which the male partner
has severely impaired or few sperm.
- Intrauterine Insemination - Insemination of sperm
into the uterus of a woman.
- In Vitro Fertilisation (IVF) - Eggs and sperm are
collected and put together to achieve fertilisation outside the
body. Up to three of the resulting embryos can be transferred into
the woman's womb and a pregnancy may occur.
- Laparoscopy - This is a surgical procedure for
looking inside the pelvic cavity. Usually under a general
anaesthetic, a small cut is made below the navel and a fine
optical instrument is inserted. Laparoscopy is used in egg
collection.
-
- Late Onset Disorder &endash; Disorders that normally become
symptomatic in adult life.
- Live Birth - The delivery of one or more babies.
- Live Birth Rate - The number of live births
achieved from every 100 treatment cycles commenced.
- Male Factor - This term covers any reason why the
male partner's sperm may be less effective or incapable of
fertilisation, including the absence of viable sperm and a failed
reversal of a vasectomy.
- Menstrual Cycle - A cycle of approximately one
month in the female during which the egg is released from an
ovary, the uterus is prepared to receive the fertilised egg and
blood and tissue are lost via the vagina if a pregnancy does not
occur.
- Micromanipulation - This term covers any technique
used in IVF to bypass the zona pellucida (protein shell) which
surrounds the egg, as this frequently prevents sperm which have
poor motility or morphology from penetrating and fertilising the
egg. ICSI is the most commonly used method of
micromanipulation.
- Microsurgical Epididymal Sperm Aspiration (MESA) - Retrieving
sperm directly from the epididymis.
- Miscarriage - Spontaneous complete loss of a
pregnancy before 24 weeks.
- Monogenic Disorders &endash; Disorders arising from defects in
a single gene.
- Multiple Birth - Birth of more than one baby from
a pregnancy (these are counted as single live births irrespective
of the number of babies born).
- Multiple Birth Rate - This is the percentage of
all births in which more than one baby was born.
- Multiple Pregnancy - A pregnancy in which two or more
foetal hearts are present.
- Multiple Pregnancy Rate - This rate is calculated
as a proportion of all clinical pregnancies.
- Muscular Dystrophy - A hereditary condition where
muscles slowly waste away.
- Mutation &endash; The change in a gene or chromosome that
causes a disorder or the inherited susceptibility to a
disorder.
-
- Natural/Unstimulated cycle - No drugs were given to
stimulate egg production
- Neonatal Death - The death of a baby within 27 complete
days of delivery.
- Oocyte - Another name for an egg.
- Ovary - One of a pair of female reproductive
organs which produce eggs and hormones.
- Ovarian Hyperstimulation Syndrome (OHSS) - A rare
but serious consequence of taking the drugs used to stimulate the
ovaries.
- Partial Zonal Dissection (PZD) - A variation of
IVF treatment in which a small hole is made in the outer membrane
of the egg using a small glass needle, thereby easing the passage
of sperm into the egg under their own motion.
- Percutaneous Epididymal Sperm Aspiration (PESA) - Retrieving
sperm directly from the coiled tubing outside the testicles that
store sperm (epididymis) using a needle.
- Perinatal Death - The death of a baby either in
the uterus after 24 weeks pregnancy (stillbirth) or within 28 days
after the birth.
- Polygenic or multifactorial conditions &endash; The
interaction of several genes and the environment.
- Pregnancy Rate - The number of pregnancies
achieved from every 100 treatment cycles commenced.
- Preimplantation Genetic Diagnosis (PGD) - Use of genetic
testing on a live embryo to determine the presence, absence or
change in a particular gene or chromosome prior to implantation of
the embryo in the uterus of a woman.
- Prenatal Diagnosis (PND)
- (a) Amniocentesis &endash; This method involves examining
fetal cells taken between 15 and 16 weeks of pregnancy from the
amniotic fluid which surrounds the fetus. The fetal cells are
cultured and the genetic make-up of the fetus determined. This
allows testing for chromosomal abnormalities such as Down's
syndrome and other birth defects.
- (b) Chorionic Villus Sampling (CVS) &endash; This method
involves the removal of a small sample of placental tissue between
9 and 11 weeks of pregnancy which is tested for genetic
abnormalities.
- Primitive Streak - This develops in an embryo by
day 14 when the cells which form the foetus separate from those
which form the placenta and umbilical cord.
- Recipient - the woman who receives eggs from
another woman during treatment to help her to become pregnant.
- Spermatid - An immature sperm cell.
- Stillbirth - The birth of a dead infant.
- Stimulated Cycle - A treatment cycle in which
stimulation drugs are used to produce more eggs than usual in the
woman's monthly cycle.
- Stimulation Drugs - Drugs used to stimulate a
woman's ovaries to produce more eggs than usual in a monthly
cycle; also known as superovulatory drugs.
- Sub Zonal Insemination (SUZI) - A variation of IVF
treatment where a single sperm is deposited into the perivitelline
space between the egg and its protein shell (the zona pellucida).
This technique is aimed at patients who have sperm which fail to
penetrate the zona.
- Superovulation/Stimulation - The stimulation of a
woman's ovaries with drugs to produce more eggs than usual in a
monthly cycle.
- Superovulatory Drugs - hormones given to a woman
so that she produces more eggs than usual in a monthly cycle. The
drugs contain human menopausal gonadotrophin.
- Testicular Sperm Extraction (TESE) - Retrieving sperm directly
from the testis.
- Testis - Testicle or male gonad.
- Transport (or Satellite) IVF - An arrangement
whereby IVF is carried out at a primary centre (HFEA licensed) but
other parts of the treatment (e.g. ovulation induction or egg
retrieval) are performed at a secondary centre (not necessarily
HFEA licensed). The embryology and embryo transfer take place at
the primary centre.
- Treatment Cycle :-
- a) IVF with fresh embryos: a cycle begins with the
administration of drugs for the purpose of superovulation or, if
no drugs are used, with the attempt to collect eggs;
- b) IVF with frozen-thawed embryos: a cycle begins with the
removal of the stored embryo in order to be thawed and then
transferred;
- c) DI: a cycle begins when the first insemination with donor
sperm takes place.
- Triplet or trinucleatide repeat disorders &endash; caused by
the expansion of a triplet repeat of bases within a gene and are
usually associated with neurological disorders e.g fragile X,
Huntington disease, myotonic dystrophy. Each disease has a range
of repeats associated with a spectrum from normal to affected
individuals.
- Ultrasound - investigation using sound waves to
make a picture of the womb and ovaries appear on a television
screen. Ultrasound is used in monitoring egg development and in
egg collection.
- Unknown Outcome - The outcome of a clinical
pregnancy is unknown due to incomplete information being returned
by a clinic to the HFEA.
- Unstimulated - No drugs were given to stimulate
egg production.
- X-Linked Disorders &endash; Disorders due to a mutation on the
X chromosome. X-linked disorders usually only affect males, but
the disorders can be transmitted through healthy female
carriers.
- Zona drilling (ZD) - Acid released to dissolve the gelatinous
coating of the egg leaving a hole through which the sperm can
enter.
Events