The odds of a woman having estrogen dominance and progesterone deficiency rise to 50 percent in the female population by age 35, yet doctors rarely measure progesterone concentrations. (virginiahopkinstestkits.com)
Anovulation was defined as any cycle with a peak progesterone concentration ≤ 5 ng / mL and no observed serum luteinizing hormone peak at the mid — or late — luteal phase visits (n = 42 of 509 cycles; 8.3 %); 28 women had 1 anovulatory cycle, and 7 women had 2 anovulatory cycles. (academic.oup.com)
Lachelin GCL, McGarrigle HHG, Seed PT et al, «Low saliva progesterone concentrations are associated with spontaneous early preterm labour (before 34 weeks of gestation) in women at increased risk of preterm delivery,» British Journal of Obstetrics & Gynaecology vol 116:11 pp 1515 — 1519 Published Online: 22 Jul 2009. (virginiahopkinstestkits.com)