The following is a summary of “Systemic inflammation and menstrual cycle length in a prospective cohort study,” published in the FEBRUARY 2023 issue of Obstetrics and Gynecology by Harris, et al.

Normal folliculogenesis and ovulation depend heavily on local inflammation, and diseases with chronic systemic inflammation, such as obesity, and polycystic ovarian syndrome, might impair follicular dynamics. For a study, researchers investigated the relationship between menstrual cycle length and systemic inflammation, as assessed by C-reactive protein levels.

Time to Conceive, a prospective time-to-pregnancy cohort study, provided the data for this secondary analysis. With regard to age, race, education, body mass index, the duration since using an oral contraceptive, alcohol, smoking, caffeine use, and exercise, multivariable linear mixed and marginal models were used to examine the relationship between cycle length and C-reactive protein. Time to Conceive included women who had been trying to get pregnant for <3 months and were between the ages of 30 and 44. On cycle days 2, 3, or 4, the amount of serum C-reactive protein was tested. For ≤4 months, participants reported daily menstrual cycle information.

Menstrual cycle length and the lengths of the follicular and luteal phases were the primary outcome measures. 1,409 cycles from 414 women were included in the multivariable analysis. The length of the menstrual cycle and C-reactive protein levels did not correlate linearly. Nevertheless, a C-reactive protein level >10 mg/L was linked to >3 times the risks of extended cycles (defined as ≥35 days) compared to <1 mg/L (adjusted odds ratio, 3.7; 95% CI, 1.67-8.11). When measuring the length of the follicular phase, C-reactive protein levels above 10 mg/L were linked to follicular phases that were 1.7 (95% CI, 0.23-3.09) days longer and had odds of lengthy follicular phases that were >2 times higher (adjusted odds ratio, 2.2; 95% CI, 1.05-4.74).

Systemic inflammation and alterations in the menstrual cycle may be linked pathophysiologically. More research was required to determine whether prolonged menstrual periods are a sign of increased systemic inflammation or whether they alter the menstrual cycle.