What changes occur in the menstrual cycle during perimenopause?

During perimenopause, a transitional phase before menopause, significant hormonal changes lead to various alterations in the menstrual cycle. One of the hallmark features of this phase is the occurrence of irregularities in cycle length and fluctuations in hormone levels.

As women approach menopause, the ovaries gradually produce less estrogen and progesterone, leading to erratic ovulation. This change results in variations in the duration of menstrual cycles; some cycles may become shorter, while others may be longer, creating noticeable irregularity. Additionally, hormone levels that typically fluctuate in a predictable manner during the reproductive years can become erratic during perimenopause, causing further irregularities in menstrual function.

This is in contrast to other phases of a woman's reproductive life, where cycle length is generally more consistent. Complete cessation of cycles characterizes menopause itself, while perimenopause is marked by these transitional fluctuations. Hormonal testing during this time might reveal varying levels of estradiol and other hormones, further supporting the diagnosis of perimenopause. Thus, recognizing the irregularities in cycle length and hormonal fluctuations is essential for understanding the physiological changes occurring during this phase.