Assisted reproductive
technology (ART): All treatments or procedures that include the in vitro handling of human oocytes and sperm or embryos for the
purpose of establishing a pregnancy. ART does not include artificial
(intrauterine) insemination.
Biochemical pregnancy: Evidence of conception
based only on biochemical data in the serum or urine before ultrasound evidence
of a gestational sac.
Blastocyst: An embryo with a
fluid-filled blastocoele cavity (usually developing by five or six days after
fertilization).
Cancelled cycle: An ART cycle in which
ovarian stimulation or monitoring has been carried out with the intent of
undergoing ART but which did not proceed to follicular aspiration, or in the
case of a thawed embryo, to transfer.
Clinical pregnancy rate: Number of clinical
pregnancies expressed per 100 initiated cycles, aspiration cycles, or embryo
transfer cycles. When clinical pregnancy rates are given, the denominator must
be specified.
Clinical/definitive
pregnancy:
Evidence of pregnancy by clinical (fetal heartbeat) or ultrasound parameters
(ultrasound visualization of a gestational sac, embryonic pole with heartbeat).
It includes ectopic pregnancy. Multiple gestational sacs in one patient are
counted as one clinical pregnancy.
Clomiphene citrate: An anti-estrogen drug used
to induce ovulation.
Controlled ovarian
hyperstimulation (COH): Medical treatment to induce the development of multiple ovarian
follicles to obtain multiple oocytes at follicular aspiration.
Donor oocyte: Oocytes or embryos arise
from assisted reproductive technology (ART) cycle of a donor patient (or
couple) and are transferred into a recipient.
Ectopic pregnancy: A pregnancy in which implantation takes place outside the uterine cavity.
Embryo transfer (ET): Procedure in which the
embryo(s) are placed in the uterus or fallopian tube.
Embryo transfer cycle: Assisted Reproductive
Technology (ART) cycle in which one or more embryos are transferred into the
uterus or fallopian tube.
Embryo: Product of conception from
the time of fertilization to the end of the embryonic stage eight weeks after
fertilization.
Endometrium: Uterine lining sheds monthly
to produce a menstrual period.
Estrogen: The female sex hormone
produced by the ovaries, responsible for the development of female sex
characteristics. Estrogen is largely responsible for stimulating the uterine
lining to thicken during the first half of the menstrual cycle in preparation
for ovulation and possible pregnancy.
Fertilization: The penetration of the ovum by the spermatozoon and fusion of genetic materials resulting in the development of a zygote.
Follicle-stimulating hormone
(FSH): The
pituitary hormone responsible for the stimulation of estrogen production from
the follicle cells around the egg.
Gestational sac: A fluid-filled structure
containing an embryo that develops early in pregnancy usually within the
uterus.
Gonadotropin-releasing
hormone (GnRH): A hormone secreted by the hypothalamus that prompts the pituitary
gland to release follicle stimulating hormone and luteinizing hormone into the
blood stream.
Human chorionic gonadotropin
(hCG): A
hormone produced by the placenta during pregnancy that is often used with
clomiphene or hMG to cause ovulation.
Human menopausal gonadotropin (hMG): An ovulation drug containing a mixture of follicle stimulating hormone and luteinizing hormone derived from the urine of postmenopausal women.
Hypothalamus: A thumb-sized area in the
base of the brain that regulates the pituitary.
In vitro fertilization (IVF): An Assisted Reproductive Technology (ART) procedure
that involves extracorporeal fertilization.
Infertility: Failure to conceive after
at least one year of unprotected coitus
(intercourse).
Intracytoplasmatic
(intracytoplasmic) sperm injection (ICSI): IVF procedure in which a single spermatozoon
is injected through the zona pellucida into the oocyte.
Intrauterine Insemination
(IUI):
Placement of spermatozoa that have been separated from the seminal fluid into
the endometrial cavity through a small catheter.
Live birth: A birth in which a fetus is
delivered with signs of life after complete expulsion or extraction from its
mother, beyond 20 completed weeks of gestational age. (Live births are counted
as birth events, e.g. a twin or triplet live birth is counted as one birth
event.)
Live-birth delivery rate: Number of live-birth deliveries expressed per 100 initiated cycles, aspiration cycles or embryo transfer cycles. When delivery rates are given, the denominator must be specified.
Luteinizing hormone (LH): The hormone that triggers
ovulation and stimulates the corpus luteum to secrete progesterone.
Micromanipulation (also referred to as assisted fertilization): The use of
special micromanipulative technology that allows operative procedures to be
performed on the oocyte, sperm or embryo.
Oocyte: An immature female
reproductive cell, one that has not completed the maturing process to form an
ovum (gamete).
Ovarian Hyperstimulation Syndrome (OHSS): Ovarian enlargement to a diameter of more than 6 cm as a result of stimulation of multiple follicles. This condition may be fatal in severe cases.
Ovulation: The expulsion of a mature
egg from its follicle in the outer layer of the ovary. It occurs on
approximately day 14 of a 28-day cycle and is usually determined clinically by
a serum progesterone level.
Pituitary gland: A small gland just beneath
the hypothalamus that secretes follicle stimulating hormone and luteinizing
hormone, which stimulate egg maturation and hormone production by the ovary.
Progesterone: An ovarian hormone secreted
by the corpus luteum during the second half of the menstrual cycle.
Progesterone helps prepare the endometrium to receive and nourish an embryo.
Semen Analysis: Quantitation of various
parameters of a recently ejaculated semen specimen analyzed after liquefaction
has occurred.
Ultrasound: High frequency sound waves
that produce an image on a monitor screen of internal organs.
Zygote: The diploid cell, resulting
from the fertilization of an oocyte by a spermatozoon, which subsequently
develops into an embryo.