Fertility care and IVF have a vocabulary of their own. Search for a term below, or browse by category.
| 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.