Characteristic Overall Chronotypes Chronotypes Chronotypes p
Evening Chronotype Neutral Chronotype Morning Chronotype
No. of Participants 1022 96(9.4) 697(68.2) 229(22.4)
Age (%) 0.010
≤29 377 (36.9) 41 (42.7) 268 (38.5) 68 (29.7)
30-34 457 (44.7) 46 (47.9) 305 (43.8) 106 (46.3)
≥35 188 (18.4) 9 (9.4) 124 (17.8) 55 (24.0)
Sex (Female, %) 608 (59.5) 56 (58.3) 428 (61.4) 124 (54.1) 0.148
Education (%) 0.011
Middle school or below 302 (29.5) 24 (25.0) 190 (27.3) 88 (38.4)
High/ vocational school 382 (37.4) 43 (44.8) 263 (37.7) 76 (33.2)
College degree or above 338 (33.1) 29 (30.2) 244 (35.0) 65 (28.4)
Annual incomes (%) 0.043
<30, 000 388 (38.0) 30 (31.2) 255 (36.6) 103 (45.0)
30, 000-60, 000 242 (23.7) 23 (24.0) 178 (25.5) 41 (17.9)
≥60, 000 392 (38.4) 43 (44.8) 264 (37.9) 85 (37.1)
Passive smoking (%) <0.001
Never 326 (31.9) 49 (51.0) 220 (31.6) 57 (24.9)
Occasionally 591 (57.8) 45 (46.9) 419 (60.1) 127 (55.5)
Frequently 105 (10.3) 2 (2.1) 58 (8.3) 45 (19.7)
Physical activity (%) 0.467
Low 342 (33.5) 34 (35.4) 223 (32.0) 85 (37.1)
Moderate 341 (33.4) 31 (32.3) 244 (35.0) 66 (28.8)
Vigorous 339 (33.2) 31 (32.3) 230 (33.0) 78 (34.1)
Cause of infertility (%) 0.923
Male factor 179 (17.5) 14 (14.6) 126 (18.1) 39 (17.0)
Female factor 365 (35.7) 39 (40.6) 242 (34.7) 84 (36.7)
Both 249 (24.4) 21 (21.9) 174 (25.0) 54 (23.6)
Unexplained 229 (22.4) 22 (22.9) 155 (22.2) 52 (22.7)
Living children (yes, %) 162 (15.9) 9 (9.4) 105 (15.1) 48 (21.0) 0.020
Infertility treatment time 0.335
≤6 month 342 (33.5) 40 (41.7) 223 (32.0) 79 (34.5)
7-12 month 217 (21.2) 17 (17.7) 152 (21.8) 48 (21.0)
13-24 month 310 (30.3) 26 (27.1) 223 (32.0) 61 (26.6)
>24 month 153 (15.0) 13 (13.5) 99 (14.2) 41 (17.9)
Frequency of insomnia (%) <0.001
Never 236 (23.1) 14 (14.6) 156 (22.4) 66 (28.8)
Occasionally or ≤3 per month
687 (67.2)
60 (62.5)
476 (68.3)
151 (65.9)
≥4 per month 99 (9.7) 22 (22.9) 65 (9.3) 12 (5.2)
Nocturnal wake frequency (%) 0.087
Never 158 (15.5) 23 (24.0) 106 (15.2) 29 (12.7)
Occasionally 471 (46.1) 42 (43.8) 327 (46.9) 102 (44.5)
≥1 per night 393 (38.5) 31 (32.3) 264 (37.9) 98 (42.8)
Daytime napping (%) 0.004
Never 295 (28.9) 41 (42.7) 199 (28.6) 55 (24.0)
<1 525 (51.4) 33 (34.4) 366 (52.5) 126 (55.0)
≥1 202 (19.8) 22 (22.9) 132 (18.9) 48 (21.0)
Social jetlag (≥1 h, %) 211 (20.6) 29 (30.2) 147 (21.1) 35 (15.3) 0.009
Nighttime sleep duration (≥8 h, %) 680 (66.5) 71 (74.0) 454 (65.1) 155 (67.7) 0.210
Depression symptoms (yes, %) 527 (51.6) 68 (70.8) 364 (52.2) 95 (41.5) <0.001