Table 1 Demographic, social and reproductive characteristics at the time of the index date of women diagnosed with primary infertility between 1980 and 1999 and age-matched female controls
From: Fertility trends and comparisons in a historical cohort of US women with primary infertility
Characteristic at the index date†| Primary infertility (N = 1001) | Controls (N = 1001) | Unadjusted OR (95% CI) from univariable models | Adjusted OR (95% CI) from a full multivariable model |
|---|---|---|---|---|
Age (years) |  |  | –§ | –§ |
Mean (SD) | 29.2Â (4.4) | 29.2Â (4.4) | Â | Â |
Range | (18.4–45.9) | (18.2–46.1) |  |  |
 18–25 | 238 (23.8%) | 232 (23.2%) |  |  |
 26–30 | 455 (45.5%) | 451 (45.1%) |  |  |
 31–35 | 228 (22.8%) | 241 (24.1%) |  |  |
 36–40 | 72 (7.2%) | 67 (6.7%) |  |  |
 41–50 | 8 (0.8%) | 10 (1.0%) |  |  |
Race | ||||
 Caucasian | 797 (79.6%) | 761 (76.0%) | 1.24 (1.00, 1.53) | 1.33 (1.00, 1.76) |
 Black or African American | 11 (1.1%) | 5 (0.5%) |  |  |
 Asian | 28 (2.8%) | 23 (2.3%) |  |  |
 Native Hawaiian or Pacific Islander | 0 (0.0%) | 1 (0.1%) |  |  |
 American Indian or Alaskan Native | 1 (0.1%) | 6 (0.6%) |  |  |
 Other | 13 (1.3%) | 14 (1.4%) |  |  |
 Unknown or chose not to disclose | 151 (15.1%) | 191 (19.1%) |  |  |
Ethnicity | ||||
 Hispanic or Latino | 25 (2.5%) | 9 (0.9%) | 3.00 (1.35, 6.68) | 4.48 (1.69, 11.84) |
 Not Hispanic or Latino | 726 (72.5%) | 722 (72.1%) |  |  |
 Unknown or chose not to disclose | 250 (25.0%) | 270 (27.0%) |  |  |
Marital Status | ||||
 Single | 15 (1.5%) | 337 (33.7%) |  |  |
 Married | 966 (96.5%) | 646 (64.5%) | 15.54 (10.10–23.92) | 14.83 (9.51, 23.11) |
 Partnered (not married) | 20 (2.0%) | 10 (1.0%) |  |  |
 Not documented | 0 (0.0%) | 8 (0.8%) |  |  |
Level of education | ||||
 Less than high school | 12 (1.2%) | 33 (3.3%) |  |  |
 High school graduate | 129 (12.9%) | 201 (20.1%) |  |  |
 Some college | 274 (27.4%) | 335 (33.5%) |  |  |
 College (4-yr) graduate | 340 (34.0%) | 226 (22.6%) | 1.78 (1.48, 2.14) | 1.74 (1.37, 2.21) |
 Beyond college | 159 (15.9%) | 135 (13.5%) | ||
 Not documented | 87 (8.7%) | 71 (7.1%) |  |  |
Tobacco use | ||||
 Current or Former | 225 (22.5%) | 356 (35.6%) | 0.54 (0.45–0.66) | 0.70 (0.55, 0.90) |
 Never | 770 (76.9%) | 632 (63.1%) |  |  |
 Not documented | 6 (0.6%) | 13 (1.3%) |  |  |
BMIÂ (kg/m2) | ||||
Mean (SD) | 24.1 (5.7) | 24.8 (5.9) | 0.90 (0.83, 0.97) | 0.98 (0.89, 1.09) |
 Less than 18.5 | 49 (4.9%) | 26 (2.6%) |  |  |
 18.5–24.9 | 645 (64.4%) | 617 (61.6%) |  |  |
 25–29.9 | 179 (17.9%) | 190 (19.0%) |  |  |
 30–39.9 | 88 (8.8%) | 118 (11.8%) |  |  |
 40 or more | 27 (2.7%) | 28 (2.8%) |  |  |
 Not documented | 13 (1.3%) | 22 (2.2%) |  |  |
Regular menstrual cycles | ||||
 Yes | 706 (70.5%) | 830 (82.9%) | 0.49 (0.40, 0.61) | 0.51 (0.39, 0.67) |
 No | 295 (29.5%) | 130 (13.0%) |  |  |
 Not documented | 0 (0.0%) | 41 (4.1%) |  |  |
Contraceptive use prior to index date | ||||
 Yes | 765 (76.4%) | 723 (72.2%) | 1.26 (1.02, 1.55) | 0.99 (0.77, 1.29) |
 No | 230 (23.0%) | 249 (24.9%) |  |  |
 Not documented | 6 (0.6%) | 29 (2.9%) |  |  |
Contraceptive use prior to index date | ||||
 Combined (estrogen/progesterone containing pills, patches, or inserts) | 715 (71.4%) | 675 (67.4%) | 1.22 (1.00, 1.48) |  |
 Progestin only | 7 (0.7%) | 15 (1.5%) | 0.47 (0.19, 1.14) |  |
 Intrauterine device | 12 (1.2%) | 19 (1.9%) | 0.61 (0.29, 1.29) |  |
 Implant (Nexplanon, Implanon) | 4 (0.4%) | 9 (0.9%) | 0.44 (0.14, 1.44) |  |
 Barrier | 107 (10.7%) | 63 (6.3%) | 1.76 (1.27, 2.43) |  |