IVF and fertility acronyms explained: your go-to glossary

If you’ve just started navigating fertility treatment, there’s a good chance you’ve come across a wave of confusing acronyms. From TTC and AMH to IUI and FET, the language of fertility can feel like a complex code you’re expected to crack, often at one of the most emotional times in your life.
We’ve created this glossary to help you feel more informed, less overwhelmed, and fully supported, because to be frank – understanding your path to parenthood shouldn’t require a translator.
Whether you're prepping for an IVF cycle, exploring IUI, egg freezing, or are just starting to track your ovulation, here's what all those fertility and IVF abbreviations actually mean.
Common Fertility Acronyms (When You’re TTC)
TTC – Trying to Conceive
Used widely across forums and communities to describe people actively trying to get pregnant.
TWW – Two-Week Wait
The time between ovulation or embryo transfer and when you can take a pregnancy test.
DPO – Days Past Ovulation
Helpful when tracking symptoms in the TWW.
AF – Aunt Flo
A casual way to say your period.
BD – Baby Dance
Fertility forum speak for timed sex during your fertile window.
OPK – Ovulation Predictor Kit
Used to detect your LH surge and pinpoint ovulation.
LH – Luteinizing Hormone
The hormone that triggers ovulation.
CM – Cervical Mucus
Tracking changes in texture can help identify ovulation.
Hormones & Diagnostic Testing
AMH – Anti-Müllerian Hormone
A key marker of your ovarian reserve (aka how many eggs you likely have left).
FSH – Follicle Stimulating Hormone
Tells your ovaries to start maturing follicles. Higher levels can indicate lower egg reserve.
E2 – Estradiol
A form of estrogen that rises as follicles grow. Often monitored during IVF stimulation.
HSG – Hysterosalpingogram
An X-ray to check if your fallopian tubes are open.
SHG – Sonohysterogram
An ultrasound using saline to assess your uterus.
DOR – Diminished Ovarian Reserve
A lower number (or quality) of eggs than expected for your age.
PCOS – Polycystic Ovary Syndrome
A hormonal condition that can impact ovulation.
RE – Reproductive Endocrinologist
A fertility specialist — someone trained to help with conception and hormonal issues.
Treatment Acronyms: IVF, IUI & more
IVF – In Vitro Fertilization
Eggs and sperm are combined in a lab to create embryos.
IUI – Intrauterine Insemination
Sperm is placed directly into the uterus around ovulation.
ICSI – Intracytoplasmic Sperm Injection
A single sperm is injected directly into an egg (often used in IVF when there are sperm-related concerns).
FET – Frozen Embryo Transfer
A previously frozen embryo is thawed and transferred into the uterus.
ET – Embryo Transfer
The final step in an IVF cycle — when the embryo is placed in the uterus.
PIO – Progesterone in Oil
An injection that supports the uterine lining during the luteal phase and early pregnancy.
HCG Trigger – Human Chorionic Gonadotropin
A shot used to trigger ovulation before egg retrieval or IUI.
ERA – Endometrial Receptivity Analysis
A test that pinpoints the best timing for your embryo transfer.
Embryo Testing & Genetics
PGT-A – Preimplantation Genetic Testing for Aneuploidy
Screens embryos for chromosomal abnormalities before transfer.
PGT-M – Preimplantation Genetic Testing for Monogenic Conditions
Used when there’s a known genetic condition in your family.
PGT-SR – Preimplantation Genetic Testing for Structural Rearrangements
Recommended when someone has a known chromosome translocation or inversion.
Cycle Tracking & Outcomes
CD – Cycle Day
CD1 is the first day of your period. Helpful when planning treatment timing.
BFN / BFP – Big Fat Negative / Big Fat Positive
A community shorthand for pregnancy test results.
5DT / 3DT – 5-Day Transfer / 3-Day Transfer
Refers to how many days after fertilization the embryo is transferred.
PUPO – Pregnant Until Proven Otherwise
A term people use after transfer during the two-week-wait.
CP – Chemical Pregnancy
A very early pregnancy loss, often before a heartbeat is detected.
MMC – Missed Miscarriage
A loss where the body hasn’t yet shown signs like cramping or bleeding.
Donor Conception & Surrogacy
DE – Donor Eggs
Eggs used from another person in your IVF cycle.
DS – Donor Sperm
Sperm used from a donor, either known or anonymous.
GC – Gestational Carrier
Someone who carries a pregnancy for another person or couple (often referred to as a surrogate).
There’s no sugarcoating it: fertility treatment can be a lot. But knowledge is power — and we’re here to make sure you never feel alone in the process.
At Gaia, we believe in putting people first. That means clear information, accessible care, and support that goes beyond the clinic. If you're exploring IVF, IUI, egg freezing, or simply wondering where to begin, we're here to guide you through every step.
Whether you’re planning for treatment or just want to understand your options, Gaia helps you access fertility treatment with flexible payment plans and personalized support, so you can focus on what matters most — your family.
Learn more about Gaia’s financing options here.
How can Gaia help?
A Gaia Plan is the most affordable way to start and protect your IVF.
Start your IVF with fixed costs that you only pay once you have a child.