These effects result from acceleration of the termination of lactational amenorrhea. Breastfeeding delays the return of menstruation and fertility, a phenomenon known as lactational amenorrhea. Exclusive breastfeeding inhibits ovulation in some women (Lactational amenorrhea). The production of prolactin in response to suckling is important to maintaining lactational amenorrhea. The older a woman was, the longer period of lactational amenorrhea she demonstrated. The use of lactational amenorrhea method (LAM) can be seen across the world. Breastfeeding and extended breastfeeding can also increase birth spacing due to lactational amenorrhea. The therapeutic disadvantage is a breast without a sensitive NAC, and without lactational capability. Facultative diapause is also known as lactational delayed implantation due to its regulation via lactation. The average length of postpartum amenorrhoea is longer when breastfeeding; this is termed lactational amenorrhoea. Its "seasonal and lactational control of its reproduction" make its reproduction particularly suited for study. Lactational amenorrhea has evolved as a mechanisms for preserving the health of the mother. The time in which a lactating woman does not menstruate is called lactational amenorrhea. The lactational amenorrhea method (LAM) requires breast feeding at least every four to six hours.