Success rates vary with the number of embryos transferred. However, transferring more and more embryos at one time does not increase the chance of live birth significantly, but may only increase the risk of a multiple pregnancy, and its associated risks. The impact of the number of embryos that are transferred also varies with the age of the woman.  
Many people of sub-Saharan Africa choose to foster their children to infertile women. IVF enables these infertile women to have their own children, which imposes new ideals to a culture in which fostering children is seen as both natural and culturally important. Many infertile women are able to earn more respect in their society by taking care of the children of other mothers, and this may be lost if they choose to use IVF instead. As IVF is seen as unnatural, it may even hinder their societal position as opposed to making them equal with fertile women. It is also economically advantageous for infertile women to raise foster children as it gives these children greater ability to access resources that are important for their development and also aids the development of their society at large. If IVF becomes more popular without the birth rate decreasing, there could be more large family homes with fewer options to send their newborn children. This could result in an increase of orphaned children and/or a decrease in resources for the children of large families. This would ultimately stifle the children's and the community's growth.[134]
"Demographers tend to define infertility as childlessness in a population of women of reproductive age," whereas "the epidemiological definition refers to "trying for" or "time to" a pregnancy, generally in a population of women exposed to" a probability of conception.[8] Currently, female fertility normally peaks at age 24 and diminishes after 30, with pregnancy occurring rarely after age 50.[9] A female is most fertile within 24 hours of ovulation.[9] Male fertility peaks usually at age 25 and declines after age 40.[9] The time needed to pass (during which the couple tries to conceive) for that couple to be diagnosed with infertility differs between different jurisdictions. Existing definitions of infertility lack uniformity, rendering comparisons in prevalence between countries or over time problematic. Therefore, data estimating the prevalence of infertility cited by various sources differs significantly.[8] A couple that tries unsuccessfully to have a child after a certain period of time (often a short period, but definitions vary) is sometimes said to be subfertile, meaning less fertile than a typical couple. Both infertility and subfertility are defined as the inability to conceive after a certain period of time (the length of which vary), so often the two terms overlap.
Problems with your periods or menstrual cycle is a sign of ovulation problems – and if you aren’t ovulating, you won’t get pregnant. Menstrual problems are the most obvious sign of infertility in women – but they don’t necessarily mean you’re infertile. Most women have some type of problem with their period: light flow, heavy flow, clotting, irregularity caused by stress or weight fluctuations, hormonal changes, etc.

During the second half of your menstrual cycle, the hormone progesterone kicks in to help prepare the lining of your uterus for a fertilized egg. If the egg isn't fertilized and doesn't implant, it disintegrates, progesterone levels fall, and about 12 to 16 days later, the egg -- along with blood and tissues from the lining of the uterus -- is shed from the body. That process is menstruation. It usually lasts 3 to 7 days.

Ovulation induction (in the sense of medical treatment aiming for the development of one or two ovulatory follicles) is an alternative for women with anovulation or oligoovulation, since it is less expensive and more easy to control.[7] It generally involves antiestrogens such as clomifene citrate or letrozole, and is followed by natural or artificial insemination.

Repeated failed rounds of IVF can help identify causes of infertility. For example, if sperm and egg quality are normal, then the conception issue may be rooted at the embryonic or implantation level. In other words, if IVF fails to result in pregnancy despite successful fertilization, embryonic development or implantation may be to blame. Still this is a very expensive way to start getting answers.