Frequency and type of premature or early menopause in a geographically defined American population

There is limited information on the prevalence of premature and early menopause. Therefore, we studied the frequency and type of premature (age < 40 years) or early (age 40-44 years) menopause in a geographically-defined American population.

We studied a random sample of women aged 18 to 50 years who resided in Olmsted County, MN between 1988 and 2007. Women were followed through December 2021, and age at cessation of menses was assessed via review of the medical records included in a medical records-linkage system. Menopause was defined as cessation of menses due to spontaneous or induced ovarian insufficiency.

1015 women (71.3 %) underwent spontaneous menopause, 138 (9.7 %) underwent bilateral oophorectomy, 17 (1.2 %) had antecedent chemotherapy or radiation therapy, and 254 (17.8 %) underwent hysterectomy or endometrial ablation. The median age at cessation of menses was 51.0 years (IQR, 49.0-52.0) for spontaneous menopause, 46.0 years (IQR, 41.0-49.0) for menopause induced by oophorectomy, chemotherapy, or radiation therapy, and 38.0 years (IQR, 33.0-44.0) for hysterectomy. Considering both spontaneous and induced menopause, the frequency was 3.1 % (95 % CI, 2.2-4.2) for premature and 6.2 % (95 % CI, 5.0-7.8) for early menopause. Considering only spontaneous menopause, the frequency reduced to 0.4 % (95 % CI, 0.2-1.0) for premature and 5.2 % (95 % CI, 4.0-6.8) for early menopause. However, considering all types of cessations of menses, the frequency was 12.2 % (95 % CI, 10.6-14.0) for premature and 9.7 % (95 % CI, 8.3-11.3) for early cessation of menses.

Approximately 3 % of women in the general population experienced either spontaneous or induced premature menopause. The most common cause of premature menopause was bilateral oophorectomy.