In Vitro Fertilization, or IVF, is generally attempted after other, less-invasive fertility treatments have failed. IVF is an effective option for women with many types of reproductive issues, but certain groups tend to experience higher success rates than others.

In Vitro Fertilization often provides results for women whose infertility can be traced to ovulation disorders, endometriosis, and cervical problems. IVF has also helped couples reproduce when male factor infertility is the problem, as well as in cases in which the cause of the woman's infertility is unknown.

Although there is some difference of opinion among experts about the ideal age of an IVF candidate, thirty-five is commonly cited as the latest age at which positive results should be expected. One reason is that fertility sharply decreases after the age of forty in most cases. Women under thirty-five are more likely to have a greater number of eggs, increasing their odds for fertilization due to sheer numbers.

Tests are available to determine the number of eggs. A vaginal ultrasound can be used to discover how many viable eggs there are for each ovary; anything over fifteen per ovary is highly desirable. Blood tests can also be used to find the levels of anti-mullerian hormone, or AMH. The higher the level of AMH for the woman's age group, the better. Since AMH levels decrease with age as the corresponding number of eggs wane, it is impossible to pinpoint a target level. However, women with anti-mullerian hormone numbers in the top fifty percent of their own age group fare best.

Obese women, considered by the National Institutes of Health to be those with a body mass index of 30 or higher, often experience more difficulty with IVF for varying reasons. Being overweight can reduce egg visibility during an ultrasound, making extraction of the eggs from the ovaries more difficult. Assuming all other conditions are favorable, however, treatment can be attempted by patients after losing weight.

Women who have previously attempted in vitro fertilization, and whose treatment was canceled due to the possibility of hyperstimulation syndrome, which causes pain and swelling of the ovaries, are good IVF candidates. And, as with most medical treatments, women who are in good overall health have the best chance of a successful outcome.