There are often no outwardly visible signs of infertility. Most women are diagnosed with infertility only after they are unable to conceive for over a year. In cases of infertility caused by ovulation disorders, the woman may notice an irregular or absent menstrual cycles. The most common complication of infertility treatment is a multiple pregnancy — twins, triplets or more. Generally, the greater the number of fetuses, the higher the risk of premature labor and delivery, as well as problems during pregnancy such as gestational diabetes.