IUI vs. IVF: How the Two Fertility Treatments Differ
How IUI and IVF work, who each is commonly used for, what NIH sources say about success and multiple births, and why CDC clinic data covers only IVF.
By FertilityList Editorial (AI-assisted, data-driven) · Last updated
This guide is general information, not medical advice. Talk to a qualified clinician about your situation. Disclaimer.
Intrauterine insemination (IUI) and in vitro fertilization (IVF) are two of the most common fertility treatments. They differ in where fertilization happens, how intensive they are, and how outcomes are tracked. This guide compares them using US government health sources. It describes the options; it does not recommend one for any individual.
The basic difference
- IUI: NICHD describes IUI as placing a man’s sperm into a woman’s uterus using a long, narrow tube.[1] Fertilization then happens inside the body.
- IVF: eggs are retrieved from the ovaries and fertilized with sperm in a laboratory; an embryo is then placed in the uterus.[1][3]
The CDC states that IUI is not considered an assisted reproductive technology (ART) procedure because it does not involve the manipulation of eggs. ART covers treatments that handle eggs or embryos, and IVF is the most common type.[4]
Step by step
| IUI | IVF | |
|---|---|---|
| Medication | Optional; can be combined with ovulation-stimulating medicine | Injected medicines to make many eggs mature, typically for 8 to 14 days |
| Procedure | Sperm placed in the uterus through a thin tube | Egg retrieval with a needle guided by ultrasound, under mild sedation |
| Fertilization | Inside the body | In the laboratory, sometimes by ICSI |
| Embryos | Not seen or selected | Grown for several days; extras can be frozen |
Sources for the table: NICHD describes IUI with or without ovulation medication, and the IVF steps of superovulation (injections for 8 to 14 days), egg retrieval 34 to 36 hours after an hCG injection (a procedure that normally takes about 30 minutes), fertilization and embryo transfer.[1] MedlinePlus describes embryo culture and ICSI.[3]
Who each is commonly used for
NICHD lists IUI as most effective for infertility involving:[1]
- Scarring or defects of the cervix
- Low sperm counts or low sperm mobility
- Men who cannot get erections, or who have retrograde ejaculation
- Couples who have difficulty having intercourse
IUI is also commonly used with donor sperm, for example by single women and female couples. See fertility treatment for single parents and LGBTQ+ families.
MedlinePlus says IVF is most often tried when other, less expensive fertility techniques have failed.[3] NICHD notes that medications are least likely to help when infertility is caused by damaged fallopian tubes or severe endometriosis, but that IVF can help women with these conditions conceive.[2] IVF is also needed for donor eggs, gestational carriers, embryo genetic testing and egg or embryo freezing.[4]
Success rates
NICHD states that IUI success depends on the cause of infertility, and that with monthly inseminations using fresh or frozen sperm, success rates can be as high as 20% per cycle, depending on whether fertility medicines are used, the woman’s age and the diagnosis.[1]
IVF outcomes are reported to the CDC by clinic. In 2022, nationally, 49.7% of intended egg retrievals resulted in a live birth for patients under 35 using their own eggs, and 7.7% for patients over 40.[5] These figures are not directly comparable with IUI rates: they are measured differently and describe different groups of patients. See IVF success rates by age.
Multiple pregnancies
Ovulation-stimulating medicines used with or without IUI can increase the chance of twins or more. NICHD reports about a 10% chance of twins with clomiphene, and that 30% of women who conceive with gonadotropins have multiple births.[2] In IVF, the number of embryos transferred can be controlled; transferring a single embryo lowers the chance of multiples. See frozen vs. fresh embryo transfer.
Why IUI is missing from clinic success data
Because the CDC does not classify IUI as ART, the clinic success rates on FertilityList, which come from the CDC’s National ART Surveillance System, cover IVF and related procedures only.[4][5] If you are considering IUI, ask clinics for their own IUI results, and how they define success.
Other things people weigh
- Cost: IVF involves more medication, procedures and laboratory work than IUI. Insurance coverage varies by state and plan.
- Time: IUI is often repeated over several cycles; IVF cycles take longer each but produce more information, such as how many eggs and embryos develop.
- Age: MedlinePlus notes fertility begins to decline around age 35, which can affect timing decisions.[6]
Moving from IUI to IVF
Many people start with less intensive treatment and move to IVF if it does not work, which matches MedlinePlus’s description of IVF as most often tried after other, less expensive techniques.[3] Others go straight to IVF because of their diagnosis, their age, or a need for donor eggs, a gestational carrier or embryo testing. The right sequence depends on test results and personal circumstances, which is a conversation to have with a fertility specialist.
Questions to ask a clinician
- Based on our tests, is IUI a reasonable first step, or is IVF more appropriate?
- How many IUI cycles would you try before discussing IVF?
- What are this clinic’s IUI results for patients like us?
- What is the risk of twins with the medicines you propose?
Related guides
Sources
- NICHD, National Institutes of Health. Assisted Reproductive Technology (ART). Accessed November 13, 2026.
- NICHD, National Institutes of Health. Fertility Treatments for Females. Accessed November 13, 2026.
- MedlinePlus, U.S. National Library of Medicine. In vitro fertilization (IVF) (Medical Encyclopedia). Accessed November 13, 2026.
- Centers for Disease Control and Prevention (CDC). ART Glossary. Accessed November 13, 2026.
- CDC, National ART Surveillance System. 2022 Final Assisted Reproductive Technology (ART) Summary (dataset). Accessed November 13, 2026.
- MedlinePlus, U.S. National Library of Medicine. Infertility (Medical Encyclopedia). Accessed November 13, 2026.
First published November 13, 2026. Found an error? See our corrections policy.