Menstrual Cycle Characteristics and the Risk of Endometriosis

Darrow SL, S L Darrow, Sherri L. Darrow, J E Vena, John E. Vena, Vena JE, Ronald E. Batt, R E Batt, Batt Re, Zielezny MA, Maria Zielezny, M A Zielezny, Michalek AM, Arthur M. Michalek, A M Michalek, Sharon Selman, Selman S, S Selman
Epidemiology (Cambridge, Mass.) · 1993 · vol. 4(2) , pp. 135–142 · doi:10.1097/00001648-199303000-00009 · PMID:8452902 · W2067525249
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⚙ AI-generated summary by gemini-2.5-flash-lite, 2026-06-08 ⓘ

This case-control study found that for women under 30, prolonged menstrual flow, heavy flow, severe cramps, increasing symptoms, and long-term tampon use were associated with an increased risk of endometriosis.

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⚙ AI-generated deep summary by gpt-5.6-luna, 2026-08-12 · read from full text ⓘ

This case-control study examined whether menstrual cycle characteristics were associated with endometriosis risk among women aged 19–45 years. Researchers compared 104 laparoscopically confirmed cases from a Western New York gynecologic clinic with 100 friend controls and 98 medical controls, using age-stratified logistic regression adjusted for pregnancy, religion, and body mass index. Among women younger than 30, longer or heavier menstrual flow, severe cramps, increasing symptoms, and earlier or prolonged tampon use were associated with elevated odds of endometriosis, with generally weaker associations among older women; similar findings for flow duration, cramps, and increasing symptoms appeared with medical controls. The paper is centrally about endometriosis — the relationship between menstrual cycle characteristics and disease risk.

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Abstract

The present study utilized a case-control design to assess the relation between menstrual cycle factors and risk of endo-metriosis in women age 19–45 years. From a gynecologic specialty clinic in Western New York in 1987, we identified 104 laparoscopically confirmed cases of endometriosis. We used two control groups: (1) 100 friend controls (friends of cases), and (2) 98 medical controls (patients from the same medical practice with conditions other than endometriosis). Controls were frequency matched to cases by age. Because crude odds ratios (ORs), stratified by age (< 30 vs ≥ 30 years), revealed effect modification by age, we performed all analyses by age group. We used logistic regression to calculate ORs and 95% confidence intervals (CIs), controlling for pregnancy, religion, and body mass index. Among women under age 30, using friend controls, we observed elevated risks for menstrual flow ≥6 days per month (OR = 2.5, 95% CI = 1.1–5.9), heavy flow (OR = 2.5, 95% CI = 1.1–6.3), severe cramps (OR = 2.5, 95% CI = 1.2–6.0), increasing symptoms (OR = 6.6, 95% CI = 2.6–16.5), and tampon use ≥14 years (OR = 3.6, 95% CI = 1.04–13.5). Risks were also elevated for women age 30 and over, but not to the same degree as among younger women. Using medical controls, we observed elevated risks for menstrual flow ≥6 days (OR = 2.3, 95% CI = 1.1–5.1), severe cramps (OR = 2.3, 95% CI = 1.1–5.3), and increasing symptoms (OR = 8.3, 95% CI = 3.3–21.0) among women under age 30. These results support theories that associate endometriosis with increased exposure to menstruation.
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Menstrual Cycle Characteristics and the Risk of Endometriosis - Sherri L. Darrow - John E. Vena - Ronald E. Batt - Maria A. Zielezny - Arthur M. Michalek - Sharon Selman The present study utilized a case-control design to assess the relation between menstrual cycle factors and risk of endo-metriosis in women age 19–45 years. From a gynecologic specialty clinic in Western New York in 1987, we identified 104 laparoscopically confirmed cases of endometriosis. We used two control groups: (1) 100 friend controls (friends of cases), and (2) 98 medical controls (patients from the same medical practice with conditions other than endometriosis). Controls were frequency matched to cases by age. Because crude odds ratios (ORs), stratified by age (< 30 vs ≥ 30 years), revealed effect modification by age, we performed all analyses by age group. We used logistic regression to calculate ORs and 95% confidence intervals (CIs), controlling for pregnancy, religion, and body mass index. Among women under age 30, using friend controls, we observed elevated risks for menstrual flow ≥6 days per month (OR = 2.5, 95% CI = 1.1–5.9), heavy flow (OR = 2.5, 95% CI = 1.1–6.3), severe cramps (OR = 2.5, 95% CI = 1.2–6.0), increasing symptoms (OR = 6.6, 95% CI = 2.6–16.5), and tampon use ≥14 years (OR = 3.6, 95% CI = 1.04–13.5). Risks were also elevated for women age 30 and over, but not to the same degree as among younger women. Using medical controls, we observed elevated risks for menstrual flow ≥6 days (OR = 2.3, 95% CI = 1.1–5.1), severe cramps (OR = 2.3, 95% CI = 1.1–5.3), and increasing symptoms (OR = 8.3, 95% CI = 3.3–21.0) among women under age 30. These results support theories that associate endometriosis with increased exposure to menstruation.

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Condition tags

endometriosis

MeSH descriptors

Endometriosis Menstrual Cycle Adult Body Mass Index Case-Control Studies Contraception Endometriosis Endometriosis Female Humans Menstrual Hygiene Products Menstruation Middle Aged New York New York Odds Ratio Retrospective Studies Risk Factors Smoking

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