Additionally, couples may turn to assisted reproductive technology, the most common of which is in vitro fertilization (IVF). Other techniques may include special injections or using a donor's eggs or sperm. Complications can sometimes occur, the most common being bleeding or infection; ovarian hyperstimulation syndrome, in which the ovaries become swollen and painful; and multiple pregnancies.
Sometimes problems getting pregnant for a second or subsequent time are related to a complication that occurred in a prior pregnancy or prior to delivery (damage to the uterus, for instance). But most often, secondary infertility is caused by the same factors that would cause primary infertility — issues like advanced age, obesity, ovulation problems and so on.