Table 1. Baseline Characteristics According to Offspring Exposure to Maternal HDP.
| Characteristic | Offspring, No. (%) | |||
|---|---|---|---|---|
| No HDP (n = 2 432 469) | Preeclampsia or eclampsia (n = 70 465) | Hypertension (n = 34 487) | Total (n = 2 537 421) | |
| Outcome | ||||
| No | 2 416 910 (99.36) | 69 799 (99.05) | 34 207 (99.19) | 2 520 916 (99.3) |
| Yes | 15 559 (0.64) | 666 (0.95) | 280 (0.81) | 16 505 (0.7) |
| Singleton | ||||
| No | 76 476 (3.14) | 6 420 (9.11) | 1 504 (4.36) | 84 400 (3.3) |
| Yes | 2 355 993 (96.86) | 64 045 (90.89) | 32 983 (95.64) | 2 453 021 (96.7) |
| Sex | ||||
| Boy | 1 247 135 (51.27) | 36 633 (51.99) | 17 859 (51.78) | 1 301 627 (51.3) |
| Girl | 1 184 003 (48.67) | 33 793 (47.96) | 16 618 (48.19) | 1 234 414 (48.6) |
| Unknown | 1 331 (0.05) | 39 (0.06) | 10 (0.03) | 1 380 (0.1) |
| Maternal parity | ||||
| 1 | 1 081 546 (44.46) | 46 281 (65.68) | 16 307 (47.28) | 1 144 134 (45.1) |
| 2 | 910 979 (37.45) | 16 353 (23.21) | 11 645 (33.77) | 938 977 (37.0) |
| ≥3 | 439 944 (18.09) | 7 831 (11.11) | 6 535 (18.95) | 454 310 (17.9) |
| Maternal age at childbirth, y | ||||
| <20 | 55 607 (2.29) | 2 111 (3.00) | 321 (0.93) | 58 039 (2.3) |
| 20-24 | 420 422 (17.28) | 14 356 (20.37) | 3 703 (10.74) | 438 481 (17.3) |
| 25-29 | 883 768 (36.33) | 25 175 (35.73) | 10 065 (29.18) | 919 008 (36.2) |
| 30-34 | 736 200 (30.27) | 18 472 (26.21) | 11 557 (33.51) | 766 229 (30.2) |
| ≥35 | 336 472 (13.83) | 10 351 (14.69) | 8 841 (25.64) | 355 664 (14.0) |
| Maternal smoking during pregnancya | ||||
| No | 1 331 155 (77.22) | 39 723 (80.99) | 23 862 (83.90) | 1 394 740 (77.4) |
| Yes | 317 090 (18.39) | 6 895 (14.06) | 3 529 (12.41) | 327 514 (18.2) |
| Unknown | 75 647 (4.39) | 2 429 (4.95) | 1 050 (3.69) | 79 126 (4.4) |
| Maternal education duration at childbirth, y | ||||
| 0-9 | 632 432 (26.00) | 19 812 (28.12) | 6 967 (20.20) | 659 211 (26.0) |
| 10-14 | 1 035 184 (42.56) | 31 244 (44.34) | 15 297 (44.36) | 1 081 725 (42.6) |
| ≥15 | 721 102 (29.64) | 18 594 (26.39) | 11 827 (34.29) | 751 523 (29.6) |
| Unknown | 43 751 (1.80) | 815 (1.16) | 396 (1.15) | 44 962 (1.8) |
| Maternal cohabitation at childbirth | ||||
| No | 1 104 341 (45.40) | 36 311 (51.53) | 16 079 (46.62) | 1 156 731 (45.6) |
| Yes | 1 324 415 (54.45) | 34 131 (48.44) | 18 398 (53.35) | 1 376 944 (54.3) |
| Unknown | 3 713 (0.15) | 23 (0.03) | 10 (0.03) | 3 746 (0.1) |
| Maternal residence at childbirth | ||||
| Copenhagen | 281 456 (11.57) | 7 884 (11.19) | 3 739 (10.84) | 293 079 (11.6) |
| City with ≥100 000 inhabitants | 313 767 (12.90) | 9 536 (13.53) | 5 116 (14.83) | 328 419 (12.9) |
| Other | 1 837 246 (75.53) | 53 045 (75.28) | 25 632 (74.32) | 1 915 923 (75.5) |
| Maternal country of origin | ||||
| Denmark | 294 956 (12.13) | 5 550 (7.88) | 2 685 (7.79) | 303 191 (11.9) |
| Not Denmark | 2 130 963 (87.60) | 64 819 (91.99) | 31 762 (92.1) | 2 227 544 (87.8) |
| Unknown | 6 550 (0.27) | 96 (0.14) | 40 (0.12) | 6 686 (0.3) |
| Maternal income | ||||
| No income | 439 493 (18.98) | 10 757 (15.99) | 5 133 (15.29) | 455 383 (18.8) |
| Less than the lower tertiles | 624 787 (26.99) | 19 254 (28.61) | 8 207 (24.45) | 652 248 (27.0) |
| Lower and higher tertiles | 623 272 (26.92) | 19 128 (28.43) | 10 173 (30.31) | 652 573 (27.0) |
| More than the higher tertiles | 624 967 (27.00) | 18 143 (26.96) | 10 047 (29.93) | 653 157 (27.0) |
| Unknown | 2 552 (0.11) | 9 (0.01) | NRb | 2 565 (0.1) |
| Prepregnancy maternal BMIc | ||||
| <18.5 | 37 185 (4.20) | 578 (2.24) | 399 (2.02) | 38 162 (4.1) |
| 18.5-24.9 | 525 047 (59.24) | 11 697 (45.26) | 8 454 (42.87) | 545 198 (58.5) |
| 25.0-29.9 | 175 326 (19.78) | 6 554 (25.36) | 4 814 (24.41) | 186 694 (20.0) |
| ≥30.0 | 99 384 (11.21) | 6 182 (23.92) | 5 391 (27.34) | 110 957 (11.9) |
| Unknown | 49 372 (5.57) | 835 (3.23) | 660 (3.35) | 50 867 (5.5) |
| Maternal RE history before childbirth | ||||
| No | 2 424 213 (99.66) | 70 166 (99.58) | 34 275 (99.39) | 2 528 654 (99.7) |
| Yes | 8 256 (0.34) | 299 (0.42) | 212 (0.61) | 8 767 (0.3) |
| Paternal RE history before childbirth | ||||
| No | 2 399 617 (98.65) | 69 287 (98.33) | 33 915 (98.34) | 2 502 819 (98.6) |
| Yes | 7 559 (0.31) | 204 (0.29) | 136 (0.39) | 7 899 (0.3) |
| Unknown | 25 293 (1.04) | 974 (1.38) | 436 (1.26) | 26 703 (1.1) |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); HDP, hypertensive disorder of pregnancy; NR, not reported; RE, refractive error.
a
Maternal smoking during pregnancy was available in Denmark from 1991 to 2018.
b
Not allowed to report when there were fewer than 6 cases due to data protection in Denmark.
c
Prepregnancy maternal BMI was available in Denmark from 2004 to 2018.