This information is for couples who have fertility problems caused by male infertility. It tells you about injecting sperm into the womb, a treatment used for these types of fertility problems. It is based on the best and most up-to-date research.
Does it work?
Yes. When the male partner has fertility problems caused by a low sperm count or poor-quality sperm, this treatment more than doubles the chances of the woman becoming pregnant.
It also works twice as well as another similar treatment where doctors put sperm into the neck of the womb.
What is it?
This is when doctors put sperm directly into the womb. Doctors call it intrauterine insemination (or IUI for short).
Guidelines for doctors say that you should be offered up to six cycles of insemination because this increases the chance of pregnancy. 
Here's what happens:
The man will be asked to masturbate to produce a sample of semen in the clinic
The semen is washed and treated to remove unwanted cells
Doctors monitor the woman with an ultrasound probe to see if she is ovulating
Using a fine tube, they inject the treated semen up through the vagina and into the womb at around the time that the woman is ovulating.
Sometimes doctors inject the sperm into the neck of the womb instead. This is called intracervical insemination. It's less painful than injecting sperm right into the womb.
Sometimes the woman may have hormone treatments to help her ovulate, especially if she is not ovulating regularly. Common hormone treatments are:
How can it help?
Couples who have this treatment are twice as likely to get pregnant during each menstrual cycle as those who have sex naturally. 
Having the sperm injected right into the womb works twice as well as having it injected into the neck of the womb. 
We're not sure if it increases the chances of pregnancy to have more than one sample of sperm out in the womb during a menstrual cycle. There's not enough research to say.
However, not all studies showed that injecting sperm helped more than having sex normally. 
How does it work?
Sperm injected into the womb don't have to swim so far to get to the fallopian tubes to fertilise the egg. They also don't have to get through the acid fluid in the vagina, which kills a high proportion of sperm, or the mucus at the neck of the womb. Preparing the semen before they're injected means only the best sperm are used.
All this is important if you're a man with a low sperm count or have sperm that are not good swimmers. If the woman has hormone treatment, this will boost the number of eggs released. This gives the sperm an even better chance since they can target not one but several eggs.