Breast tenderness and swelling found in normal ovulation

Breast tenderness and swelling found in normal ovulation | Image Credit: © Syda Productions - © Syda Productions - stock.adobe.com.

Mild breast tenderness and swelling are expected before the next period among women with a normal menstrual cycle, according to a recent study by the University of British Columbia.¹

New insight into breast symptoms and ovulation

The trial evaluated breast tenderness on a 0 to 4 scale, reporting a median of 1.4 among the study population. Additionally, the change in breast size on a 1 to 5 scale was 4, with 3 indicating no change. This provides new data about the link between breast symptoms and ovulation.¹

“This is the first longitudinal study to characterize breast experiences with confirmed ovulation,” said Jerilynn C. Prior, MD, FRCPC, principal investigator. “We were surprised to find that women actually had more breast tenderness and swelling when they had normal ovulation, compared to ovulatory disturbed cycles with short luteal phases.”¹

Daily diary and ovulation assessment

The study was conducted to evaluate differences in recorded breast tenderness among healthy women with normally ovulatory vs ovulatory-disturbed cycles.² Participants included women aged 20 to 41 years with 2 consecutive normal-length and normal ovulatory cycles.

These patients also had a body mass index (BMI) of 18.5 to 24.9, did not smoke, and had not taken any hormonal contraception in the past 6 months. Using the Menstrual Cycle Diary, participants recorded daily cycle and general experiences before bed, including breast tenderness and changes in breast size.²

Ovulation was assessed using the Quantitative Basal Temperature analysis. Cycles were classified as either normally ovulatory, short luteal phase, or anovulatory. These were defined as 10 days or more, under 10 days, and no significant temperature rise in under 4 days, respectively.²

Breast tenderness was measured on a score of 0 to 4, with 0 indicating no tenderness and 4 very intense tenderness. Similarly, breast size was measured on a scale of 1 to 5, with 1 indicating much less and 5 indicating much increased.²

More Symptoms in normal ovulation

Participants were aged an average 34 years and had an average BMI of 22 and average age at menarche of 11.5 years. Of menstrual cycles, 97% were the normal length. Additionally, 71% were normal ovulatory, 26% short luteal phase, and 3% anovulatory. Mean cycle lengths did not differ between normally ovulatory cycles and anovulatory cycles.²

In cycles lasting for 28.1 days, the median breast tenderness was 1.4. Baseline data did not differ based on breast tenderness, and all breast tenderness occurred during the luteal or premenstrual phase. However, normal ovulatory cycles had significantly increased mean breast tenderness intensity and duration.²

Comparing normal and disturbed ovulatory cycles

In cycles with Subclinical Ovulatory Disturbances (SOD), the median Breast Tenderness Score was 3, vs 6 in normally ovulatory cycles. Additionally, the score for breast size changes was 4, and these changes lasted a median 4 days per cycle. Normal ovulatory cycles presented with significant increases in breast size and its duration vs SOD cycles.²

Breast swelling scores were 4 and 4, respectively, while days of breast enlargement were 5 and 3, respectively. When assessing ovulation status within-women, median Breast Tenderness Scores were 5.9 and 5.7, respectively, while breast tenderness scores were 1.24 vs 1.21, respectively, with durations of 4.5 vs 4.3 days, respectively.²

Implications and future research

These results indicated mild breast tenderness and swelling are common before flow in cycles with normal ovulation. Investigators recommended further research about premenopausal normal breast experiences linked to ovarian hormone levels.²

“These results are exciting because a better understanding of what are ‘normal’ or ‘healthy’ menstrual cycle experiences are critical in order to identify women with recurrent ovulatory disturbances even though their cycles are regular and of normal lengths,” said Mary Wood, MD, internal medicine resident at the University of British Columbia.¹

References

1. Mild breast tenderness and a little swelling before flow are expected in healthy ovulatory cycles. EurekAlert. May 27, 2025. Accessed Mary 28, 2025. https://www.eurekalert.org/news-releases/1085202.
2. Wood M, Shrin S, Goshtasebi A, Prior JC. Breast tenderness and swelling experiences related to menstrual cycles and ovulation in healthy premenopausal women: Secondary analysis of the 1-year “Prospective Ovulation Cohort”. PLOS One. 2025. doi:10.1371/journal.pone.0321205