What defines the onset of perimenopause (perimenopausal transition)?

From the Research

Definition of Perimenopause

The onset of perimenopause, also known as the perimenopausal transition, is characterized by:

• Irregular menstrual cycles [(1,2,3)]
• Hormonal fluctuations, including variable levels of estradiol and progesterone [(1,2)]
• Menopausal symptoms, such as hot flashes and night sweats [(2,4)]
• Changes in bleeding patterns, including menorrhagia 1
• Increased risk of mood disorders 1

Stages of Perimenopause

The perimenopausal transition is divided into two stages:

• Early menopausal transition, characterized by mostly regular menstrual cycles with relatively few interruptions 5
• Late transition, characterized by prolonged amenorrhea lasting for at least 60 days, up to the final menstrual period 5

Hormonal Changes

During perimenopause, hormonal levels fluctuate, including:

• A fall in ovarian secretion of inhibin B 2
• A rise in follicle-stimulating hormone 2
• Maintained or increased levels of estradiol 2
• Fluctuations in luteal function 2

Clinical Presentation

The clinical presentation of perimenopause includes:

• Infertility 1
• Vasomotor symptoms, such as hot flashes and night sweats [(2,4)]
• Vaginal and sexual changes 4
• Altered mood and sleep 4
• Changing bleeding patterns [(1,4)]