What happens in IUI
In intrauterine insemination, prepared sperm is placed inside the uterus around the planned ovulation window. Fertilisation, if it occurs, still happens inside the body.
What happens in IVF
In IVF, the ovaries are stimulated and monitored, eggs are collected, fertilisation takes place in the laboratory, embryos are observed and an embryo may later be transferred to the uterus.
The two treatments ask different biological questions
IUI mainly improves the timing and placement of sperm while leaving fertilisation inside the body. IVF allows eggs, fertilisation and early embryo development to be managed and observed in the laboratory before transfer.
Why IUI may be considered first in some situations
When the tubes are open, semen findings are compatible with IUI and there is no strong reason to move directly to IVF, a clinician may discuss IUI as a less intensive option. Age and the duration or cause of infertility remain important.
Why IVF may be recommended instead
IVF may be considered when tubal disease, significant sperm-related concerns, age, reduced time for lower-intensity treatment, previous failures or other clinical factors make it a more appropriate pathway.
Ask about the rationale, not which treatment sounds more advanced
The most useful comparison is which treatment fits your diagnosis and goals, what the expected trade-offs are and when the team would change strategy if the first plan does not work.