Table 1.

Characterization of Endometrial Study Groups

Study groups	n	Cycle day	Estradiol (nmol/L)*	Progesterone (nmol/L)†	Luteinizing hormone (mIU/ml)
Early menstrual	8	1.7 ± 0.67	0.14 ± 0.15	1.77 ± 0.42	3.5 ± 0.23
Late menstrual	10	4.1 ± 0.37	0.19 ± 0.25	1.57 ± 0.32	4.3 ± 0.13
Early proliferative	9	9.8 ± 2.7	0.25 ± 0.09	1.34 ± 0.42	6.8 ± 1.9
Late proliferative	11	15.0 ± 3.7	0.71 ± 0.15‡	1.74 ± 0.35	29.6 ± 16.3¶
Early secretory	12	19.6 ± 1.2	0.39 ± 0.12	36.04 ± 18.41	5.49 ± 1.77
Late secretory	9	26.0 ± 0.81	0.34 ± 0.16	23.3 ± 11.4§	3.4 ± 0.57

Study participants were divided into six study groups based on cycle day of biopsy, and serum estradiol, progesterone, and luteinizing hormone levels. The late proliferative group was defined by significantly higher estradiol and luteinizing hormone levels. Additionally, significantly higher progesterone levels in the secretory groups are indicative of ovulation, a criteria necessary for study entry. Values are expressed as mean ± SD. Comparisons between groups evaluated by analysis of variance and Student-Newman test.

*1 nmol/L estradiol = 272.4 pg/ml.

^†1 nmol/P = .314 ng/ml.

^‡Late proliferative versus menstrual, early proliferative, late proliferative (P < 0.001); early secretory versus menstrual, early proliferative, late proliferative (P < 0.001).

^§Late secretory versus menstrual, early proliferative, late proliferative, early secretory (P < 0.05).

^¶Late proliferative versus all other groups (P < 0.01).