Definition - What does Missed Period mean?
In a previously menstruating woman, a period can be described as missed when expected monthly bleeding does not occur. Typically, a healthy woman has around twelve menstrual cycles every year that occur every 21-35 days; a missed period may be one of the first signs of pregnancy, but in some situations it may also indicate a fertility disorder.
FertilitySmarts explains Missed Period
During the process of ovulation, an egg is released from an ovary and hormones prepare the uterus for potential implantation of a fertilized egg and subsequent pregnancy. Even though a woman has a fertile window, where peak cervical mucus can increase the length of sperm survival up to five days, the egg itself can only live for 12-24 hours. If the egg is not fertilized in this time period, the blood rich uterine lining that prepared for implantation of a fertilized egg breaks down and sheds; this bleeding is known as menstruation or a period.
If a sperm fertilizes the egg, the fertilized egg or blastocyst becomes implanted in the uterus and menstruation does not occur, resulting in what is described as a missed period.
In some hormone imbalance disorders, such as polycystic ovary syndrome (PCOS), a period is missed not because the egg is fertilized, but because an egg was never released in the first place in what is known as an anovulatory cycle.
Amenorrhea may occur if a previously menstruating woman does not menstruate for three or more consecutive months.