Intrauterine Insemination (IUI) : Process and Risks

Assisted reproduction technologies are helping many women who are having trouble conceiving realize their hopes of starting a family. One of the most common methods offered to help couples conceive is artificial insemination, or more specifically, intrauterine insemination. Let’s run through the process to see if it could be right for you.

What is intrauterine insemination (IUI)?

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Intrauterine insemination (IUI) which injects sperm cells into the uterus is the most used form of artificial insemination (AI). AI is a process by which sperm cells from a husband or partner, or from a third-party donor, are placed directly into the mother’s reproductive organs.

In an IUI procedure, a semen sample is prepared or washed before depositing healthy sperm cells directly into the uterus. To increase the chances of a pregnancy, this is performed as close as possible to the time of ovulation. For women with fertility troubles, this may be used alongside ovulation induction therapies.

Who uses IUI?

couple homosexual same sex relationship
According to the national infertility association Resolve, intrauterine insemination can be an excellent choice for couples experiencing unexplained infertility troubles. As long as there is enough semen to work with and the mother has at least one functioning fallopian tube, your doctors may consider IUI as a fertility treatment. In particular, it may be suitable for:

  • Situations where vaginal intercourse is difficult or impossible
  • Mild endometriosis
  • Mild male factor fertility issues 
  • Situations where you or your partner wants to reduce the risk of passing on certain infections

Even in the absence of fertility issues, IUI is also a fertility option for couples in the LGBT community, as well as single women using donor sperm.

IUI process timeline

phase step process
Intrauterine insemination might seem a little more complicated at first, but the process itself is quite straightforward. Here’s a quick run-through of what you can expect in a successful cycle.

Phase 1: Predicting ovulation(Menstrual Cycle Day 1 to 7)

The trickiest part of getting pregnant with IUI is getting the timing right. In order to increase your chances of pregnancy, you’ll need to work out when your ovulation day is likely to be.

If you’re ovulating with 28-day cycles, this usually falls between Day 12 to Day 16 of your cycle (in other words, 12 to 16 days after you got your last period). However, if you’re not ovulating, your doctor may recommend a course of fertility drugs to induce ovulation.

Phase 2: Monitoring for signs of ovulation(Day 10 to Day 12)

Since the timing of IUI is so important, your clinic may offer you home ovulation predictor kits, or transvaginal ultrasound to check on how the ovarian follicle is developing. Alternatively, you may be offered a trigger shot of hormones to make sure you ovulate at a particular time.

Phase 3: Insemination procedure (Around ovulation, Day 12 – 16)

The procedure is usually carried out at the clinic within 24 hours of natural or induced ovulation. If you’re using sperm from a male partner or known donor, he’ll be asked to prepare a fresh semen sample by masturbation. Frozen samples from a sperm bank will need to be thawed and prepared.

The semen is then “washed” – a lab procedure that filters the fast sperm cells from slower ones, as well as the debris and prostaglandins in seminal fluid that can cause the uterine contraction.

Once the sperm is ready, the mother will be prepared for the procedure. The vagina is held open using an instrument called a speculum, and the washed sperm is then placed directly into the mother’s uterus using a thin tube (catheter).

This isn’t usually painful, though some women do find it a bit uncomfortable or experience some cramping. Fortunately, the whole process is over in about 10 minutes.

Phase 4: Check for Pregnancy

A pregnancy test will be carried out about 14 days after the procedure to see if an egg has implanted. If not, the insemination procedure can be repeated for another cycle.

IUI effectiveness

The success rate of any assisted reproduction technique depends on a number of individual factors, particularly age. A study on women in the UK who used donor sperm to get pregnant with IUI found the following results in terms of live births as a result of a given treatment cycle1:

  • Under 35: 15.8%
  • Ages 35 to 39: 11.0%
  • Ages 40 to 42: 4.7%
  • Ages 43 to 44: 1.2%
  • Over 44: 0%

Since fertility declines with age, IUI is not very successful for women over 40 hoping to conceive. For this reason, many couples with the mother over 40 will choose to move straight to IVF, which offers higher pregnancy rates, rather than beginning their fertility treatment with IUI.

It’s also worth noting pregnancy rates are increased for women undergoing IUI as part of their infertility treatment when it’s combined with fertility drugs to induce ovulation. Even if you’re not experiencing infertility, your doctor may recommend ovulation induction to help you conceive sooner and reduce the cost of treatment cycles.

IUI risks


Intrauterine insemination is generally a very safe procedure. There is always a slight risk of infection in the uterus from the insertion of the catheter or from impurities in the sperm, but this is rare, and a skilled doctor will help you avoid this.

Research shows that babies born through IUI and natural ovulation cycles aren’t at any increased risk of birth defects. Combining IUI with fertility drugs does increase the risk of pregnancy problems, but this is largely as a result of the fact that ovulation induction can lead to multiple pregnancies.

IUI could be your fertility answer

couple pregnant belly
All sorts of families have used IUI as a safe and effective to start a pregnancy. Although the natural drop-off in fertility with age mean that it’s not appropriate for everyone, the fact that it’s effective and less expensive than IVF makes it an attractive first-line option for many people struggling to conceive. Consider talking to your fertility specialist about IUI if you’re having trouble conceiving, or you’re considering using donor sperm.