The IVF Glossary Nobody Gave You

The first time I walked into a fertility clinic, I felt like I had stumbled into a conversation already in progress. Everyone around me seemed to speak a language I hadn’t learned yet — acronyms flying around, abbreviations in every forum post, shorthand that assumed you already knew what it meant.

Nobody handed me a decoder ring. I had to figure it out as I went.

Consider this that decoder ring. Whether you’re just starting out, deep in a cycle, or trying to make sense of what someone posted in an infertility forum at 11pm, this glossary covers the terms you’ll encounter most — organized roughly in the order you’re likely to need them.

Before You Start: The Basics

TTC — Trying to Conceive. The umbrella term for the whole endeavor, from the optimistic early days to the years-long marathon some of us end up running.

RE — Reproductive Endocrinologist. The fertility specialist you’ll work with for IVF and most assisted reproduction. Not your regular OB, not a general gynecologist — an RE is the specialist who oversees your treatment protocol and monitoring.

MFM — Maternal Fetal Medicine specialist, also called a perinatologist. You may be referred to one during pregnancy, particularly if you’re advanced maternal age or have a higher-risk pregnancy. I see an MFM rather than a standard OB for my current pregnancy. It sounds scarier than it is.

BMI — Body Mass Index. Brought up here because, as I’ve written about, BMI requirements are a significant and deeply frustrating barrier to fertility treatment at many clinics. If you’ve been turned away due to BMI, you are not alone and you are not out of options.

Baseline — An ultrasound and bloodwork appointment, typically on cycle day 2 or 3, that establishes your starting point before a treatment cycle begins. Your RE is checking your antral follicle count, hormone levels, and uterine lining.

AFC — Antral Follicle Count. The number of small resting follicles visible on ultrasound at the start of a cycle. It’s used to estimate ovarian reserve — how many eggs you might have available.

AMH — Anti-Müllerian Hormone. A blood test that measures ovarian reserve. Low AMH suggests fewer eggs remaining; high AMH can indicate conditions like PCOS. It’s one of the first tests most REs order.

FSH — Follicle Stimulating Hormone. Another marker of ovarian reserve, measured via bloodwork. Elevated FSH can indicate diminished ovarian reserve.

The Diagnoses

MFI — Male Factor Infertility. Infertility attributed to sperm quality, quantity, or motility issues. More common than people realize, and one half of our personal diagnosis.

DOR — Diminished Ovarian Reserve. Fewer eggs remaining than expected for your age, indicated by low AMH, high FSH, or low antral follicle count.

Unexplained Infertility — When testing doesn’t identify a clear cause. Somehow, simultaneously the most frustrating and most common diagnosis in fertility care.

Combined Factor Infertility — When both partners have contributing diagnoses. We got this one. A two-for-one nobody puts on their wish list.

Stimulation and Retrieval

Stims / Stimming — The injectable hormone medications used to stimulate the ovaries to produce multiple follicles in a single cycle. This phase typically lasts 8-14 days and involves daily injections.

E2 — Estradiol. A form of estrogen monitored via bloodwork throughout a stim cycle to track follicle development.

Trigger Shot — An injection of hCG (human chorionic gonadotropin) or Lupron given at a precise time to trigger final egg maturation before retrieval. Timing matters — this is a “set your alarm” situation.

ER — Egg Retrieval. The procedure where eggs are collected from the follicles under sedation. You won’t be awake for it; you will be sore afterward.

Fertilization Report — The call you get the day after retrieval, telling you how many eggs were fertilized. The number almost always drops from retrieval to fertilization, and then again to blast. This is normal, and it is still hard to hear every time.

Blast / Blastocyst — An embryo that has developed to the blastocyst stage, typically by day 5 or 6 after fertilization. Blastocysts are the stage most commonly used for transfer or freezing.

Genetic Testing

PGT-A — Preimplantation Genetic Testing for Aneuploidy. Genetic screening of embryos before transfer to identify chromosomal abnormalities. Embryos with the correct number of chromosomes are called euploid; those with abnormalities are aneuploid. We did PGT-A on our embryos. Our first batch came back with zero viable embryos. It is as crushing as it sounds, and it’s more common than the fertility world tends to advertise.

Euploid — A chromosomally normal embryo with the correct number of chromosomes. A euploid embryo does not guarantee a successful pregnancy, but it does reduce certain risks.

Aneuploid — A chromosomally abnormal embryo. Most aneuploid embryos will not result in a viable pregnancy. This is one of the arguments for PGT-A testing, though the decision to test is personal and worth discussing thoroughly with your RE.

Donor Cycles

DE — Donor Egg. Using eggs from a donor rather than your own eggs. The resulting embryo carries the donor’s genetics rather than the birth parent’s. For those of us who pursued this path after years of closed doors, it is worth saying: donor-conceived children are fully, completely yours in every way that matters.

DS — Donor Sperm. Using sperm from a donor rather than a partner’s sperm. Can be used independently or, as in our case, in combination with donor eggs.

Double Donor / Donor Embryo — When both egg and sperm come from donors, creating an embryo with no genetic connection to either intended parent. This was our path. I won’t pretend the emotional processing was instant, but I also won’t pretend I feel anything other than complete when I think about our daughter.

Known Donor vs. Anonymous Donor — Some people use a known donor (a friend, family member, or someone they’ve connected with directly). Others use an anonymous donor through an agency or bank. Both are valid; both come with their own emotional and logistical considerations.

Matching — The process of selecting your donor or donors, typically through a profile that includes physical characteristics, education, health history, and sometimes personal essays or photos. It is surreal in a way that’s hard to describe until you’re doing it.

Transfer

FET — Frozen Embryo Transfer. The transfer of a previously frozen embryo into the uterus. Most transfers today are FETs rather than fresh transfers. Our transfer in December 2025 was our first FET after nine years of trying.

Fresh Transfer — The transfer of an embryo in the same cycle it was created, without freezing. Less common now, but still used in some protocols.

Lining — Short for uterine lining, or endometrium. Before a transfer, your RE will monitor your lining thickness and appearance via ultrasound. A “trilaminar” lining (a specific layered appearance) at a thickness of at least 7-8mm is generally considered ideal for transfer.

ERA — Endometrial Receptivity Analysis. A test that attempts to identify your specific “window of implantation” — the precise timing when your lining is most receptive to an embryo. Not universally recommended, but sometimes used after failed transfers.

Transfer Day — The procedure itself, which is far less dramatic than retrieval. No sedation required. It takes about 10-15 minutes. You spend the rest of the day having strong feelings about everything.

The Two Week Wait and Beyond

2WW — Two Week Wait. The approximately 10-14 days between embryo transfer and your first pregnancy blood test. Widely regarded as one of the hardest parts of the entire process, and not without reason.

Beta — The blood test that measures hCG levels to confirm pregnancy. “Getting your beta” is the moment of reckoning after the 2WW. A rising beta (tested 48 hours apart) is a good sign. The number itself matters less than the trend.

BFP — Big Fat Positive. A positive pregnancy test. The thing you’ve been working toward.

BFN — Big Fat Negative. A negative pregnancy test. Two of the hardest letters in the infertility lexicon.

Chemical Pregnancy — A very early pregnancy loss, typically before 5-6 weeks, detected by beta hCG but ending before a heartbeat is visible on ultrasound. Clinically early, emotionally significant.

NIPT — Non-Invasive Prenatal Testing. A blood test done during pregnancy, typically around 10-13 weeks, that screens for chromosomal conditions. Recommended for advanced maternal age pregnancies. If you’ve already done PGT-A, your results will likely align — but many providers recommend both as complementary confirmation.

The Community Shorthand

IF — Infertility.

IF Warrior — A term used in the community for people navigating infertility. Use it if it resonates; leave it if it doesn’t.

Cycle Buddy — Someone going through the same stage of a cycle at the same time. Forums and support groups are full of people looking for cycle buddies, and the solidarity is real.

POAS — Pee On A Stick. Testing at home before your official beta. Almost everyone does it. Almost no one recommends it for anxiety management.

HPT — Home Pregnancy Test. Same territory as POAS.

Sticky Baby / Sticky Vibes — Community shorthand for wishing someone a pregnancy that sticks. Corny to some, meaningful to others.

A Final Note

This list is not exhaustive; the fertility world has approximately one acronym for every emotion it puts you through, which is saying something. But these are the terms that come up most, the ones that show up in appointments and forums and 2am Google spirals.

If you hit something not on this list, drop it in the comments and I’ll add it. This is a living document, and you’re the ones living it.

Looking for more? The IVF glossary on RESOLVE: The National Infertility Association is a solid resource for clinical definitions. For the human side of all of it, you’re already in the right place.