Dominant Follicle
The dominant follicle is the one follicle that outgrows the rest in a cycle and releases the egg. It is chosen in the first half of the cycle. It makes most of that cycle's estradiol as it grows. One follicle is the usual pattern. An early ultrasound series tracked 87 cycles and found a single dominant follicle in 81 of them.1
A follicle maturation study follows it, and its collapse dates ovulation. In 71 scanned cycles, the follicle and its collapse dated ovulation in 57. The corpus luteum settled the other 14.2
A normal-looking chart does not prove the follicle behaved normally. Among 14 women whose temperature charts read as ovulatory, 5 cycles showed abnormal follicle growth and hormone levels.3
Cited in this entry
- Hilgers TW, Dvorak AD, Tamisiea DF, Ellis RL, Yaksich PJ. Sonographic definition of the empty follicle syndrome. Journal of Ultrasound in Medicine : Official Journal of the American Institute of Ultrasound in Medicine. 1989. https://pubmed.ncbi.nlm.nih.gov/2668550/
- Bouchard TP, Pierson R, Ecochard R, Lane M, Alger GE, Diment CJ, Bedaiwy M, Yong PJ, Doyle-Baker PK. Using corpus luteum formation with dominant follicle collapse to improve the criteria for identifying ovulation. Reproductive biomedicine online. 2026. https://pubmed.ncbi.nlm.nih.gov/42105719/
- Polan ML, Totora M, Caldwell BV, DeCherney AH, Haseltine FP, Kase N. Abnormal ovarian cycles as diagnosed by ultrasound and serum estradiol levels. Fertility and Sterility. 1982. https://pubmed.ncbi.nlm.nih.gov/7060784/
This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.