Table 1.
The general characteristics of the study population during 2015 to 2021 in Hefei [ (%)].
| Characteristics | All () | PROM () | Non-PROM () | -Valuea |
|---|---|---|---|---|
| Sociodemographic characteristics [ (%)] | ||||
| Age (y) | — | — | — | |
| 1,666 (24.4) | 406 (28.2) | 1,260 (23.4) | — | |
| 25–34 | 4,476 (65.6) | 912 (63.4) | 3,564 (66.2) | — |
| 682 (10.0) | 121 (8.4) | 561 (10.4) | — | |
| Education | — | — | — | 0.433 |
| Junior high school | 941 (13.8) | 184 (12.8) | 757 (14.1) | — |
| High school | 1,655 (24.3) | 348 (24.2) | 1,307 (24.3) | — |
| Bachelor’s degree and above | 4,228 (62.0) | 907 (63.0) | 3,321 (61.7) | — |
| Family income (RMB/month) | — | — | — | 0.231 |
| 2,149 (31.5) | 460 (32.0) | 1,689 (31.4) | — | |
| 4000–7999 | 4,132 (60.6) | 878 (61.7) | 3,254 (60.4) | — |
| 543 (8.0) | 101 (7.0) | 442 (8.2) | — | |
| Parity | — | — | — | |
| Primipara | 2,611 (38.3) | 642 (44.6) | 1,969 (36.6) | — |
| Multipara | 4,213 (61.7) | 797 (55.4) | 3,416 (63.4) | — |
| Season of delivery | — | — | — | 0.003 |
| Spring | 1,756 (25.7) | 386 (26.8) | 1,370 (25.4) | — |
| Summer | 1,800 (26.4) | 331 (23.0) | 1,469 (27.3) | — |
| Autumn | 1,730 (25.4) | 403 (28.0) | 1,327 (24.6) | — |
| Winter | 1,538 (22.5) | 319 (22.2) | 1,219 (22.6) | — |
| Enrollment years | — | — | — | 0.080 |
| 2015–2016 | 2,385 (35.0) | 538 (37.4) | 1,846 (34.3) | — |
| 2017–2018 | 2,569 (37.6) | 517 (35.9) | 2,052 (38.1) | — |
| 2019–2021 | 1,870 (27.4) | 384 (26.7) | 1,486 (27.6) | — |
| Perinatal health lifestyle factors [ (%)]b | ||||
| Vegetable intake (times/week) | — | — | 0.982 | |
| 231 (3.4) | 49 (3.4) | 182 (3.4) | — | |
| 6,593 (96.6) | 1,390 (96.6) | 5,203 (96.6) | — | |
| Fruit intake (times/week) | — | — | 0.917 | |
| 470 (6.9) | 100 (6.9) | 370 (6.9) | — | |
| 6,354 (93.1) | 1,339 (93.1) | 5,015 (93.1) | — | |
| Dessert intake (times/week) | — | — | 0.991 | |
| 5,633 (82.5) | 1,188 (82.6) | 4,445 (82.5) | — | |
| 1,191 (17.5) | 251 (17.4) | 940 (17.5) | — | |
| Physical activity (days/week) | — | — | — | 0.281 |
| 5,394 (79.0) | 1,154 (80.2) | 4,240 (78.7) | — | |
| 1,430 (21.0) | 285 (19.8) | 1,145 (21.3) | — | |
| Folic acid supplementation (days/week) | — | — | 0.047 | |
| 4,387 (64.2) | 893 (62.1) | 3,494 (64.9) | — | |
| 2,437 (35.7) | 546 (37.9) | 1,891 (35.1) | — | |
| Iron supplementation (days/week) | — | — | — | 0.075 |
| 5,847 (85.7) | 1,254 (87.1) | 4,593 (85.3) | — | |
| 977 (14.3) | 185 (12.9) | 792 (14.7) | — | |
| Passive smoking | — | — | — | 0.113 |
| Never | 5,598 (82.0) | 1,201 (83.5) | 4,397 (81.7) | — |
| Ever | 1,226 (18.0) | 238 (16.5) | 988 (18.3) | — |
| Perinatal health status [ (%)] | ||||
| Prepregnancy BMI () | — | — | — | 0.709 |
| 985 (14.4) | 216 (15.0) | 769 (14.3) | — | |
| 18.5–23.9 | 4,816 (70.6) | 1,014 (70.5) | 3,802 (70.6) | — |
| 1,023 (15.0) | 209 (14.5) | 814 (15.1) | — | |
| Hypertension during pregnancy | 139 (2.0) | 37 (2.6) | 102 (1.9) | 1.106 |
| Vaginitis | 783 (11.5) | 151 (10.5) | 632 (11.7) | 0.189 |
| Gestational diabetes mellitus | 1,420 (20.8) | 255 (17.7) | 1,165 (22.1) | 0.001 |
| Premature birth | 229 (3.4) | 111 (7.7) | 118 (2.2) | |
| Maternal anemia | 2,290 (33.6) | 591 (41.1) | 1,699 (31.6) | |
Note: There were no missing values for covariates. —, no data; PROM, prelabor rupture of membranes; RMB, renminbi.
a
Based on the chi-square test.
b
The frequency of vegetable intake, fruit intake, dessert intake, physical activity was during second trimester. The frequency of folic acid supplementation intake was during the first trimester. The frequency of iron supplementation was during the third trimester.