What it means
Counted from the first day of one period to the first day of the next, it averages about 28 days but normally ranges from about 21 to 35. Hormones cause an egg to mature and be released (ovulation), usually about 14 days before the next period, and the lining of the uterus to thicken. If no pregnancy occurs, the lining sheds as the menstrual period.
For the nurse
Ask the date of the last menstrual period before X-rays and some drugs, and in any client of childbearing age with belly pain. It is also used to estimate the due date in pregnancy.
At a glance
| Abbreviations | LMP (last menstrual period) |
|---|---|
| Spanish | ciclo menstrual |
| Also written | menstrual cycles |
Related terms
menopause
The time in a woman's life when menstrual periods stop for good, counted once there has been no period for 12 months in a row.
estrogen
A female sex hormone, made mainly by the ovaries, and the group of drugs that act like it.
polycystic ovary syndrome
A hormone disorder in women in which the ovaries make more male hormones than usual and often do not release an egg each month.
fertilization
The joining of a sperm and an egg to form a single new cell, the start of a pregnancy.