Endometriosis
Surgery is more effective than medicinal intervention for addressing infertility associated with endometriosis. Surgery attempts to remove endometrial tissue and preserve the ovaries without damaging normal tissue. In-vitro fertilization (IVF) procedures are effective in improving fertility in many women with endometriosis.
Human reproductive ecology
Fertility is influenced by fecundity, but has additional factors that can increase or decrease an individual's lifetime reproductive success. The inter-birth interval, the amount of time between a woman's births, impacts a woman's total fertility. This amount of time varies cross-culturally, as well as varies with different environmental constraints. Many cultures practice conscious birth spacing to adhere to the desired length of time between pregnancies, or desired number of children. Environmental concerns like fetal loss, lack of resource access, and disease may all impact fertility for females or males.