The simple idea (no memorising)
Match the tool to the trouble:
| Technique | Where fertilisation happens | Best when… |
|---|---|---|
| IUI (intrauterine insemination) | inside her tube (naturally) | mild male factor, cervical issues, unexplained — needs at least one open tube |
| IVF (in‑vitro fertilisation) | in the lab, then embryo placed in womb | blocked tubes, and many other causes |
| ICSI (intracytoplasmic sperm injection) | in the lab, one sperm injected into the egg | severe male factor |
How each works, in a line
- IUI — washed, concentrated sperm are placed straight into the womb, skipping the cervix. Fertilisation still happens in the tube, so a tube must be open.
- IVF — eggs are collected after stimulation, mixed with sperm in the lab, and a resulting embryo is transferred to the womb. Because fertilisation is external, IVF bypasses the tubes — perfect for tubal disease.
- ICSI — when sperm are too few or weak to fertilise on their own, an embryologist injects one sperm directly into the egg.
A complication to respect
Stimulating the ovaries with hormones can occasionally over‑respond — ovarian hyperstimulation syndrome (OHSS) — with swollen, fluid‑leaking ovaries. Women with PCOS (lots of follicles) are especially at risk, so modern protocols are designed to minimise it. 🚩
The "unexplained" path
When everything tests normal (up to ~1 in 3 couples), a common plan is a short course of ovulation tablets + IUI, then IVF if that doesn't work — always tailored to age and history.
Why it matters
These technologies turn many "impossible" situations into families. Understanding which tool fits which problem is both exam‑gold and deeply human — it's how you explain real hope to a real couple.
Quick check ✅
- Which technique bypasses the tubes, and which needs an open tube?
- Which patients are most at risk of OHSS, and why?
Remember this 🌟
Where we're going next → We've covered the reproductive years. Now back to the beginning of them — puberty. Concept 34.