Fertility care and IVF have a vocabulary of their own. Search for a term below, or scroll the full list.
2WW / TWW
The two-week wait — the stretch between an embryo transfer and the pregnancy test.
AF
“Aunt Flo,” forum shorthand for your period.
AFC
Antral follicle count. An ultrasound count of resting follicles, used as a rough measure of egg supply.
AMH
Anti-Müllerian hormone. A blood marker that roughly reflects how many eggs you have (ovarian reserve).
ART
Assisted reproductive technology. The umbrella term for fertility procedures that handle eggs or embryos, IVF included.
Beta / beta hCG
The blood test that confirms pregnancy and tracks whether levels are rising.
BFP / BFN
“Big fat positive / negative,” slang for the result of a pregnancy test.
Blastocyst
An embryo at about day 5 of development.
CD
Cycle day. Which day of your menstrual cycle you’re on (day 1 is the first day of your period).
COS / COH
Controlled ovarian stimulation / hyperstimulation. The injectable phase of IVF that encourages the ovaries to grow several eggs at once.
DOR
Diminished ovarian reserve. Fewer eggs available than typically expected for your age.
DP5DT
Days past a 5-day transfer. Counting the days since a day-5 embryo was transferred.
DPO
Days past ovulation. A way of counting where you are in the cycle.
E2
Estradiol. A form of estrogen, monitored during the stimulation phase.
Egg retrieval (ER / OPU)
The short procedure to collect mature eggs from the ovaries.
Embryo transfer (ET)
Placing an embryo into the uterus.
ERA
Endometrial receptivity analysis. A test that looks for the ideal timing window to transfer an embryo.
FET
Frozen embryo transfer. Transferring an embryo that was frozen from an earlier cycle.
FSH
Follicle-stimulating hormone. Signals the ovaries to grow follicles. Often checked early in a cycle.
GnRH
Gonadotropin-releasing hormone. The basis of the “agonist” and “antagonist” drugs that control the timing of ovulation.
hCG
Human chorionic gonadotropin. Doubles as the “trigger shot” hormone before retrieval and the hormone a pregnancy test detects.
HSG
Hysterosalpingogram. An X-ray with dye that checks whether the fallopian tubes are open.
ICSI
Intracytoplasmic sperm injection. A single sperm is injected directly into an egg. Often used when there are sperm-related challenges.
IUI
Intrauterine insemination. Sperm is placed directly into the uterus around ovulation. Simpler than IVF, and often tried first.
IVF
In vitro fertilization. Eggs and sperm are combined in a lab, and a resulting embryo is placed in the uterus.
LH
Luteinizing hormone. The hormone whose surge triggers ovulation.
MFI
Male factor infertility. A sperm-related cause of difficulty conceiving.
OB/GYN
Obstetrician / gynecologist. Often the first doctor you talk to, who may refer you to an RE.
OHSS
Ovarian hyperstimulation syndrome. A possible complication where the ovaries over-respond to medication.
OI
Ovulation induction. Using medication to prompt the ovaries to release an egg.
P4
Progesterone. Supports the uterine lining and early pregnancy.
PCOS
Polycystic ovary syndrome. A common hormonal condition that can affect ovulation.
PGT
Preimplantation genetic testing. Testing embryos before transfer. An umbrella term for the three types below.
PGT-A (formerly PGS)
PGT for aneuploidy. Checks whether an embryo has the right number of chromosomes.
PGT-M (formerly PGD)
PGT for monogenic disorders. Checks for a specific inherited single-gene condition.
PGT-SR
PGT for structural rearrangements. Checks for structural rearrangements in the chromosomes.
POI / POF
Primary ovarian insufficiency / premature ovarian failure. When the ovaries slow down earlier than usual.
RE
Reproductive endocrinologist. The fertility specialist you’ll actually see and work with.
REI
Reproductive endocrinology and infertility. The medical subspecialty that fertility care falls under.
RIF
Recurrent implantation failure. When transferred embryos repeatedly don’t implant.
RPL
Recurrent pregnancy loss. Experiencing multiple miscarriages.
SA
Semen analysis. A lab look at sperm count, movement, and shape.
SET / eSET
(Elective) single embryo transfer. Choosing to transfer one embryo at a time, usually to avoid twins.
SIS / SHG
Saline infusion sonohysterography. An ultrasound that checks the shape and lining of the uterine cavity.
STIMS
Stimulation hormones. The injectable medications that prompt the ovaries to grow several eggs during a cycle. Often shortened to “stims,” as in “day four of stims.”
TESE
Testicular sperm extraction. A minor surgical procedure to collect sperm directly from the testicle, used in some cases of male-factor infertility.
Trigger shot
A final injection that prompts the eggs to finish maturing before retrieval.
TSH
Thyroid-stimulating hormone. A thyroid measure; thyroid function can affect fertility.
TTC
Trying to conceive.
US
Ultrasound. Imaging used to monitor the ovaries and uterine lining during a cycle.
A note: these definitions explain the language you’ll hear, not your specific situation. Anything about your own care is a conversation for your doctor.