Table I.
Characteristics of women by number of LPD cycles.1
| Women with normal cycles | Women with at least one LPD cycle | P | |
|---|---|---|---|
| Number of women (n [%]) | 213 (86.6) | 33 (13.4) | Na |
| Age in years (mean [SD]) | 28.1 (8.2) | 24.8 (7.9) | 0.04 |
| <20 (n [%]) | 24 (75.0) | 8 (25.0) | 0.11 |
| 20–24 (n [%]) | 76 (84.4) | 14 (15.6) | |
| 25–29 (n [%]) | 36 (90.0) | 4 (10.0) | |
| 30+ (n [%]) | 77 (91.7) | 7 (8.3) | |
| Race | |||
| White | 121 (82.3) | 26 (17.7) | 0.03 |
| Black | 47 (95.9) | 2 (4.1) | |
| Asian | 28 (84.9) | 5 (15.2) | |
| Other | 17 (100.0) | 0 (0.0) | |
| BMI (kg/m2) (mean [SD]) | 24.2 (3.9) | 23.8 (3.6) | 0.62 |
| Underweight (<18.5) (n [%]) | 8 (100.0) | 0 (0.0) | 0.17 |
| Normal (≥18.5 to <25) (n [%]) | 126 (83.4) | 25 (16.6) | |
| Overweight (≥25 to <30) (n [%]) | 58 (93.6) | 4 (6.5) | |
| Obese (≥30) (n [%]) | 21 (84.0) | 4 (16.0) | |
| Percentage body fat (mean [SD]) | 29.9 (6.1) | 27.6 (5.0) | 0.05 |
| High school graduate or more (n [%]) | 184 (85.2) | 32 (14.8) | 0.09 |
| Annual household income (n [%]) | |||
| <$19 999 | 50 (94.3) | 3 (5.7) | 0.14 |
| $20 000–39 999 | 53 (88.3) | 7 (11.7) | |
| $40 000–74 999 | 56 (81.2) | 13 (18.8) | |
| $75 000–99 999 | 36 (90.0) | 4 (10.0) | |
| $100 000+ | 17 (77.3) | 5 (22.7) | |
| Sexually active (n [%]) | |||
| Ever | 171 (90.5) | 18 (9.5) | 0.002 |
| Never | 42 (73.7) | 15 (26.3) | |
| Marital status (n [%]) | |||
| Single | 154 (85.1) | 27 (14.9) | 0.25 |
| Married | 59 (90.8) | 6 (9.2) | |
| Age at menarche (years) (mean [SD]) | 12.4 (1.3) | 12.6 (1.1) | 0.37 |
| Parity (n [%]) | |||
| Nulliparous | 152 (84.4) | 28 (15.6) | 0.10 |
| Parous | 61 (92.4) | 5 (7.6) | |
| OC use, ever (n [%]) | |||
| Ever | 122 (90.4) | 13 (9.6) | 0.05 |
| Never | 89 (84.7) | 20 (18.4) | |
| Smoking (n [%]) | |||
| None | 170 (85.4) | 29 (14.6) | 0.69 |
| <1 cigarette/day | 33 (91.7) | 3 (8.3) | |
| ≥1 cigarette/day | 10 (90.9) | 1 (9.1) | |
| Vigorous exercise (minutes) (median [IQR]) | 8.5 (1.4, 17.4) | 15.1 (2.9, 33.1) | 0.02 |
| Sleep per day (h) (mean [SD]) | 7.4 (0.9) | 7.6 (0.9) | 0.25 |
| Perceived stress tertile (n [%]) | |||
| Low | 74 (35) | 8 (24) | 0.39 |
| Moderate | 71 (33) | 11 (33) | |
| High | 68 (32) | 14 (42) | |
1
LPD: defined as luteal phase duration <10 days. Continuous variables are shown as mean ± SD (unless noted otherwise) and comparison between groups was made using Student's t-test or Wilcoxon–Mann–Whitney test where appropriate. Categorical variables are shown as number (percentage) and associations were assessed using χ2 or Fisher's exact test.