A woman with one ovary usually has the same chance of getting pregnant as a woman with two. There are a few exceptions that can make getting pregnant more difficult. The remaining ovary must be attached to the remaining fallopian tube. If only an ovary and the opposite fallopian tube exist, it is much more likely that during ovulation, an egg will not pass down the fallopian tube. One with a single ovary and a single fallopian tube that are not on the same side is also at higher risk for tubal pregnancies.

If the fallopian tube and remaining ovary are both on the same side, another thing to look for is a regular period. If a woman continues to menstruate on a regular basis, this tends to be a good sign that the woman is ovulating and can get pregnant. Conversely, if periods are irregular or have stopped altogether this may signify that no ovulation is occurring, or that it is occurring on a very infrequent basis.

Usually, doctors advise patients with either one ovary or two to try for at least 15 months prior to seeking advice from fertility experts. If pregnancy has not occurred in that time, both partners should be tested. Lack of an ovary does not mean that the woman is necessarily the partner with fertility challenges.

However, if other signs of inability to get pregnant are present, like lack of a period, it may be more valuable to consult a fertility expert sooner, to see if any steps can be taken to enhance chances of conceiving. Sometimes a remaining ovary may have scarring or the fallopian tube may be scarred, inhibiting the passage of an egg. In some cases, surgery can clear scarring to make ovulation easier.

Before removing an ovary, doctors may evaluate the other ovary to make sure that it is normal and healthy. If they find this not to be the case, and removal of the first ovary is still necessary, they will usually alert the patient to potential fertility issues.

Even if one is told that pregnancy may be impossible, a woman should still pursue safer sex practices and use protection to avoid pregnancy. In some cases, the impossible occurs, and women who were thought to be previously infertile become pregnant unexpectedly. Using condoms and spermicides not only reduce the risk of pregnancy but also the spread of sexually transmitted disease. Even where pregnancy seems impossible, these methods should still be employed.