There is a lot of research into fertility problems, and much of it is carried out by clinical studies and trials.
Some researchers use clinical trials to test hypotheses, drugs and procedures. Others use these trials to observe certain techniques to asses which procedure is most effective. If you have serious fertility issues, or are not in a position to afford further treatment, you might want to consider participating in a clinical trial for a new procedure or drug.
Of course taking part in a trial is not without risk. Trials are conducted in various stages, and in the early stages of a trial the outcome usually isn't known, whereas during the final stages of a trial the procedure or treatment is being evaluated for use for the general population. Apart from health risks which will be explained to you by the researchers, one of the risks of taking part in a trial is that it might not be of any benefit to you personally. Of course the information from the study will help other people, but it still not may help you.
Taking part in a trial can take up a lot of time, and may require frequent visits to the research center. However, being a participant can also give you access to treatment that isn't generally available and it is often free. A down side is that there are many trials where the drug or treatment is tested against an ineffective placebo like a sugar pill or a dummy procedure. In these "double blind" trials neither the doctor giving the treatment nor the patient has any idea if the person is getting the experimental procedure or the placebo. This means that if you are in the 'control group' which receives the placebo you will have no benefit personally from taking part in the research study, apart from knowing that you are benefiting others. If you are in the experimental group you may find that the treatment helps you to have a baby.
Some trials are merely observational trials that enable medical students and researchers to study and learn from people with certain conditions. They may or may not give experimental treatments as well. However, the results of the study can be very useful for others, for example a recent study of stress confirmed that it is harder to get pregnant if you suffer from stress.
How To Go About It
There are over 250 fertility trials worldwide currently looking for participants. Some of these trials are just observational ones and will not offer any type of treatment. Others will be testing new drugs and procedures that may help you get pregnant. Some of the trials need male subjects with sub-fertility problems, and others need older women or women with specific conditions like PCOS.
Each trial will have its own criteria to participate and will only need a certain number of subjects. If you apply for a study and are turned down, do not take it personally. You may not fit the requirements of the study, or you may live too far away from the research center responsible. However you may be exactly the right person for a different study.
Of course if you live in or near a main medical research hospital or center it will be easier to take part in a trial. In the United States you can find out information about current medical trials from the National Institutes of Health.