You generally have the same chances of conception whether you have one ovary or two, as long as the remaining one is attached to a fallopian tube. Missing other parts of the reproductive system can also make it harder to conceive, but pregnancy is often still possible. There are several signs you can look for to see if you're still fertile, and many treatments available if you do have problems conceiving. There are some health risks linked to conceiving with one ovary, however, so it's important to discuss fertility with your medical provider.
Signs of Fertility
The main thing to watch for when you want to get pregnant and only have one ovary is ovulation. To get be able to conceive, a woman's body must first release an egg, which then travels down a fallopian tube. If it meets a sperm cell and becomes an embryo, it will implant in the walls of the uterus. Otherwise, it will die, and it and the lining of the uterus that builds up every month will be expelled from the body during menstruation.
When a woman has two ovaries, they typically take turns releasing an egg every month. If there's only one, then it usually takes over for the missing one and releases an egg each menstrual cycle, and a period should still occur. You may no longer be ovulating if your period gets irregular or stops entirely, which means that you may not be able to get pregnant naturally.
You can also track your basal body temperature, which often changes at specific points in the menstrual cycle. When doing this, it's essential to take your temperature the very first thing in the morning at the same time every day to ensure accurate readings. When you ovulate, your temperature generally rises at least 0.2°F (about 0.11°C) for three consecutive days. You can also check the consistency of your cervical mucus; if you're ovulating, it should be thinner and clearer than normal in the middle of your cycle.
Risks
Women who conceive with only one ovary may be at higher risk for ectopic, or tubal, pregnancies. This is a situation in which the embryo implants outside the uterus, usually in a fallopian tube. Fetuses in these pregnancies cannot survive, and are either miscarried, absorbed back into the body, or must be removed. Several studies show that women with only one ovary may also be more likely to conceive children with Down's Syndrome. Additionally, you may experience a normal, age-related loss of fertility sooner, since your body only has half of the eggs.
Exceptions
There are some situations that can make it more difficult for you to get pregnant naturally if you only have one ovary, like having one ovary and one opposite fallopian tube. Though this makes it less likely that an egg will pass into the uterus during ovulation, it still happens sometimes. Additionally, if one of your ovaries has a problem, you may not be able to get pregnant if the other one is removed. Doctors will usually evaluate both of your ovaries before removing one, however, and alert you to any possible fertility issues. Regardless of how many ovaries you have, if both your fallopian tubes are blocked or removed, it's unlikely that you'll be able to conceive naturally.
Treatments
Doctors usually advise all women, no matter how many ovaries they have, to try to get pregnant using natural methods for at least 15 months before consulting fertility experts. If you haven't gotten pregnant in that time, both you and your partner should be tested, since he may have fertility challenges too. When you show clear signs of infertility, like a lack of a period, it may be better to see a fertility expert sooner. Sometimes a remaining ovary may have scarring or the fallopian tube may be blocked, preventing the passage of an egg. Surgery can sometimes clear scarring to make ovulation easier.
Another fertility treatment for women in this situation includes in vitro fertilization (IVF), in which a specialist puts a fertilized egg directly into the uterus. Some women also try fertility-enhancing medications, like gonadotropin-releasing hormone (GnRH), human chorionic gonadotropin (HCG), and follicle-stimulating hormone (FSH). Though studies show that the pregnancy rates for women with one ovary with IVF or on fertility medications are about the same as those with both ovaries, the women with only one need higher dosages of medication and take a longer time to get the ovary to the same state of stimulation.
Even if none of the treatments work and you're told you can't conceive, it's best to still practice safe sex and use protection to avoid pregnancy. In some cases, the seemingly impossible occurs, and women who were thought to be previously infertile become pregnant unexpectedly. Using condoms and spermicides not only reduces the risk of pregnancy but also the spread of sexually transmitted diseases, and so should be used even if pregnancy seems very unlikely.