IVF Explained: How It Works, Success Rates, and What to Expect

What Is IVF?

“In vitro” is Latin for “in glass,” and it describes the central difference from conception in the body: fertilization happens in a laboratory dish rather than in the fallopian tube. IVF belongs to a broader category called assisted reproductive technology (ART), in which both eggs and sperm are handled outside the body.

The American College of Obstetricians and Gynecologists lists its common uses as blocked or damaged fallopian tubes, male factor infertility, endometriosis, ovulation disorders, and unexplained infertility.

Clinics reporting to the Society for Assisted Reproductive Technology (SART) performed 449,772 IVF cycles in 2024, producing 100,158 babies, roughly one in every 36 U.S. births.

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How Does IVF Work? The Four Stages of a Cycle

1. Ovarian Stimulation

In a natural cycle, the ovaries mature one egg. IVF uses injectable hormones called gonadotropins to mature several at once, giving the lab more chances at a viable embryo. Over roughly 8 to 14 days, frequent ultrasounds and blood draws allow your team to track follicle growth and adjust the dose.

A second medication keeps your body from releasing the eggs early. Ganirelix is a GnRH antagonist that inhibits the premature luteinizing hormone (LH) surge that would otherwise trigger ovulation before retrieval. It is injected daily through the mid-to-late stimulation phase until the trigger shot. Other protocols use a GnRH agonist such as leuprolide.

2. Trigger and Egg Retrieval

Once enough follicles reach adequate size, a “trigger” injection, usually human chorionic gonadotropin (hCG), is timed about 34 to 36 hours before retrieval to bring the eggs to final maturity. In antagonist protocols, a GnRH agonist trigger such as leuprolide is often used instead for people at high risk of OHSS, since it sharply lowers that risk. Retrieval is an outpatient procedure: under sedation, a thin needle guided by transvaginal ultrasound draws fluid and eggs from each follicle. Most people go home the same day.

3. Fertilization and Embryo Development

The lab fertilizes the eggs either by placing prepared sperm with them in a dish or by intracytoplasmic sperm injection (ICSI), where a single sperm is injected into each egg. ICSI is standard when male factor infertility is involved. Fertilized eggs are cultured to the blastocyst stage, around day five or six. Some patients also opt for preimplantation genetic testing for aneuploidy (PGT-A), which screens for chromosomal abnormalities before transfer.

4. Transfer and Luteal Phase Support

One embryo is usually transferred. Elective single embryo transfer is now the norm, which is why more than 97% of IVF births are singletons. The transfer is quick and does not require sedation.

Afterward, progesterone supplementation is the standard of care: it stabilizes the uterine lining, allowing an embryo to implant. If embryos are frozen for a later cycle, the lining must be built first, using estradiol for about two weeks to thicken the endometrium, then progesterone once it reaches adequate thickness. That cycle has no corpus luteum to produce progesterone naturally, so supplementation is not optional.

Medications Used in an IVF Cycle

Which medications you take depends on your protocol, and your clinic will choose based on your ovarian reserve, prior response, and whether the transfer is fresh or frozen.

• Ganirelix Acetate (Fyremadel), prevents premature ovulation during stimulation
• Progesterone (Prometrium), luteal phase support after transfer; for IVF, clinics generally use vaginal or intramuscular progesterone, since oral progesterone is less reliably absorbed for this purpose
• Estradiol (Estrace), builds the uterine lining before a frozen transfer
• Clomiphene Citrate (Clomid), used in minimal-stimulation protocols and often tried before IVF for ovulation disorders, although letrozole is now generally preferred for ovulation induction in PCOS

Gonadotropins, the trigger injection, and GnRH agonists such as leuprolide are administered as part of your clinic's protocol and are usually dispensed through a specialty pharmacy.

How Long Does IVF Take, and Is It Painful?

Plan for four to six weeks from the first stimulation injection to the pregnancy test. A frozen transfer adds another cycle for endometrial preparation.

Most of IVF is uncomfortable, not painful. The daily injections sting briefly, and intramuscular progesterone is the one many patients find hardest. Retrieval is done under sedation, so you should not feel the procedure, though bloating and cramping for several days afterward are common. Transfer is usually compared to a Pap smear.

Tell your care team if pain is severe or escalating. Significant abdominal pain, rapid weight gain, or shortness of breath after retrieval can signal ovarian hyperstimulation syndrome (OHSS), which needs prompt evaluation.

How Much Does IVF Cost, and Does Insurance Cover It?

The base cycle fee, covering monitoring, retrieval, anesthesia, lab fertilization, and one transfer, generally runs $12,000 to $17,000. Medications add $3,000 to $7,000 and are billed separately, as are ICSI, PGT-A, freezing and storage, and any later frozen transfer. All in, a single medicated cycle typically costs between $20,000 and $30,000.

Because many patients need more than one retrieval, plan for cost per baby rather than cost per cycle. Ask each clinic for an itemized sheet showing what the quoted fee excludes.

Coverage depends on your state and, more decisively, on how your employer’s plan is structured. As of 2026, 25 states and Washington, D.C. have fertility insurance laws, and of those, 15 plus D.C. specifically require IVF coverage in fully insured plans. The catch: state mandates generally do not reach self-insured employer plans, which is how many large employers structure benefits, so two people in the same state with the same diagnosis can end up with entirely different coverage.

Public coverage is narrower still. TRICARE excludes assisted reproductive technology outside a few specific circumstances, and most state Medicaid programs exclude IVF entirely. Ask your benefits administrator whether your plan is fully insured or self-funded, and have your clinic run a benefits verification.

IVF Success Rates: What the National Data Shows

Every U.S. clinic performing IVF must report its outcomes, so this is one of the few areas of medicine with public performance data. Two things make it easy to misread. First, clinics quote different denominators. Live births per embryo transfer look better than per intended egg retrieval because the latter includes cycles that never reached transfer. Confirm you are comparing the same measure.

Second, age is the dominant variable. In SART’s reporting, live births per intended egg retrieval using a patient’s own eggs ran roughly 43% under age 35, 31% at 35 to 37, 19% at 38 to 40, and about 3% past 42. Donor eggs change this picture substantially because outcomes track the egg donor's age rather than the recipient's.

Cumulative rates are the more useful metric when deciding whether to start. One retrieval can yield more than one embryo, so the chance of a live birth across all its transfers is higher than from any single transfer. The CDC’s IVF Success Estimator generates an individualized cumulative estimate based on your age, weight, and reproductive history; it's a planning tool, not a prediction.

Where to Start

The first step is not choosing a clinic. It is a full diagnostic workup for both partners, including hormone testing, ovarian reserve assessment, a semen analysis, and imaging of the uterus and fallopian tubes. The diagnosis determines the treatment path, and some causes of infertility are addressed with far less than IVF.

Two more things are worth settling before you begin, because they are harder to weigh mid-cycle: a financial plan that accounts for more than one attempt, and a stopping point decided in advance.

Clinic counselors and RESOLVE: The National Infertility Association runs support groups for people going through IVF, and you can find more resources in our Conditions pages below:

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