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Sperm preparation for IUI: from the semen sample to the washed sperm
Sperm preparation for IUI, also called the sperm wash, is the laboratory step that turns a fresh semen sample into a small, clean sample of moving sperm. The sample is layered gently over a warmed preparation medium, spun in a centrifuge, checked under the microscope and washed a second time before the IUI.
Watch the video
In this Konkani video, our consultant takes you into the laboratory on an IUI day, from the semen container to each step of the sperm preparation. Press the picture to watch it on YouTube. This guide is the same explanation in English. Its chapters:
- 0:00 What this video covers
- 0:26 Conical tube and laminar flow workstation
- 0:40 IUI medicines and warming the medium
- 2:26 Sterile semen container
- 4:25 How to collect the semen sample
- 7:01 Processing the sperm sample
- 8:56 Layering drop by drop
- 10:53 Centrifuge step
- 11:52 Why centrifuge: clean, motile sperm
- 12:48 Microscope check before and after the wash
- 13:44 Anaesthesia, monitor and ultrasound set-up
- 14:48 Inside the IVF lab: cryocans and freezing
- 16:05 IVF microscope and disposables
- 17:49 Incubators and backup
- 19:48 Collecting the sperm and second purification
Why sperm preparation for IUI is needed
In IUI, the sample goes straight into the womb near the time of ovulation, so raw semen cannot be used. Besides the moving sperm, it holds seminal fluid, dead and abnormal sperm, other cells, debris and sometimes germs. The sperm wash for IUI keeps the clean, moving sperm and leaves the rest behind in the tube.
The work area: a conical tube and a laminar flow workstation
The preparation is done in a conical-bottom test tube, so that the sperm can gather at its narrow tip, inside a laminar flow workstation: a cabinet that blows filtered air over the work to keep the sample clean. A pipette moves each liquid in small, controlled amounts.
The IUI medicine: warming the preparation medium
What our consultant calls the IUI medicine is the preparation medium: the solution the sperm are washed in, not a medicine the woman takes. The tubes of medium go into a warmer to reach body temperature, which takes at least fifteen to twenty minutes. Meanwhile, the husband is given the semen container.
Why the semen container must be sterile
The container should have a wide mouth and come in a sterile pack, sterilised and sealed by the manufacturer, so that no bacteria or viruses are inside. The sperm will go into the wife's womb, so contamination, or cross-contamination from another person's sample, must be avoided.
The same applies to a semen test. Some men are also asked for a semen culture, which looks for infection. A container carrying germs can make the culture show bacteria that were never in the semen, leading to antibiotics that were not needed. You can read how each value of the test is reported in our guide to the semen analysis report.
Semen sample collection for IUI: simple instructions
The sample is collected by masturbation into the sterile container, in the bathroom or a private room. Our consultant's practical points:
- Open the container before you begin. Opened at the last moment, a few drops can fall on the floor, and a lost part of the sample is a big loss for the couple and the doctor.
- Keep it within arm's reach. Not a few metres away.
- Take your time. There is no rush.
- The wife may help, but not through intercourse. The sample should not be collected through vaginal penetration.
The clinic tells the husband how many days to wait after his last ejaculation. If producing the sample there worries him, he should say so early, so that another arrangement can be discussed.
Layering the sample drop by drop
In the lab, the sample is layered over the warmed medium in the conical tube. The tube is held gently tilted and the sample is placed on top, drop by drop, patiently and correctly. The drops should rest on top, not sink into the medium or mix with it.
One hand holds the tube steady, without shaking, while the other places the drops. Done well, the medium stays below and the sample above, in two separate layers. If they mix, the first step has failed and the preparation starts again. This skill grows with practice.
The centrifuge step: how sperm is washed for IUI
The tube then goes into a centrifuge, which spins it for a set time. The medium has layers of different density. As it spins, healthy, moving sperm pass down through the medium to the bottom of the tube, while seminal fluid, debris, dead cells, dead or abnormal sperm and germs stay higher up.
The goal, in our consultant's words, is a naked sperm sample at the bottom: only sperm, no bacteria or viruses, and as few impurities as possible. That is why layering matters. If the sample sinks and mixes before spinning, unwanted material reaches the bottom with the sperm, and would go into the womb.
The microscope check before and after the wash
The sample is looked at under the microscope before the wash and again after it. After the wash, there should be no pus cells, which point to infection, and no bacteria. This check shows exactly what will go into the womb. Our guide to IUI for a low sperm count explains how the number of moving sperm after washing guides the choice of treatment.
Collecting the sperm and the second purification
At the end, the pipette goes straight down to the bottom of the tube, without touching the wall, and the sperm are moved into a fresh tube. Medium is added and the tube is spun again, with the timer set, for the second step of purification. The small sample of washed sperm is then ready. Every step counts equally.
Anaesthesia, monitor and ultrasound: one option
Most IUIs are done awake, without anaesthesia; our page on whether IUI is painful explains what to expect. For a woman who has found the procedure very distressing before, the video shows another option: IUI under short anaesthesia, with the anaesthesia machine, a monitor for the vital signs, and an ultrasound machine to see that the IUI is done correctly. Whether this suits you is decided with your doctor.
Inside the IVF lab
The video ends with a short look around the IVF laboratory: cryocans, tanks in which embryos, sperm and eggs can be frozen and stored (for example, the sperm of a husband who works away); the IVF microscope; sterile disposables in sealed packets; and the incubators, with a standby incubator as a backup.
Where sperm preparation fits in IUI
The sperm wash is one part of an IUI cycle; scans time the IUI to ovulation, and a soft, thin tube carries the washed sperm into the womb. Our IUI treatment page explains the whole cycle, who it suits and when another step is better. IUI is offered by Heartbeats IVF in Goa. Call or WhatsApp us to book a consultation.
About this guide
This guide is by the Heartbeats IVF team. It follows the video by our consultant, written out in English. It is for education only, not personal medical advice: your own treatment is decided by your doctor after examining you and reading your reports.
Questions couples ask about sperm preparation for IUI
Why is sperm washed before IUI?
Semen holds seminal fluid, dead and abnormal sperm, other cells, debris and sometimes germs, along with the moving sperm. In IUI the sample goes straight into the womb, so it is washed first. The sperm wash keeps the clean, moving sperm in a small volume and leaves the rest behind.
How is the semen sample collected for IUI?
By masturbation, directly into a sterile, wide-mouth container, in the bathroom or a private room. Open the container before you begin and keep it within arm's reach, so that no part of the sample is lost. The sample should not be collected through intercourse.
Why does the semen container have to be sterile?
The washed sperm are placed inside the womb, so germs or cross-contamination from the container must be avoided. A sterile container also matters for a semen culture, because germs from the container could show up in the result and lead to antibiotics that were not needed.
What does the centrifuge do in sperm preparation for IUI?
The sample is layered on top of a warmed medium of different densities and spun. Healthy, moving sperm pass down and collect at the bottom of the tube, while debris, dead cells and abnormal sperm stay above. The sperm are then moved to a fresh tube and washed a second time.
How long does the sperm wash take?
Warming the medium alone takes at least fifteen to twenty minutes, and the whole preparation is usually ready in about an hour. The lab looks at the washed sample under the microscope before it is used.
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What you read here explains fertility care in general terms and cannot replace a consultation. Decisions about your own care should be made with a doctor who knows your history and has seen you. We do not carry out or offer sex determination of any kind, which is prohibited by law in India under the PCPNDT Act.