Table. Maternal Characteristics According to Vaccination Status During Pregnancy.
| Background characteristic | No. (%) | |||
|---|---|---|---|---|
| Sweden | Norway | |||
| Vaccinated (n = 20 916) | Unvaccinated (n = 82 493) | Vaccinated (n = 7 590) | Unvaccinated (n = 46 522) | |
| Age at start of pregnancy, mean (SD), y | 32.2 (4.6) | 30.5 (4.8) | 31.4 (4.5) | 30.7 (4.7) |
| Parity, y | ||||
| 0 | 9050 (43.3) | 34 864 (42.3) | 3400 (44.8) | 19 442 (41.8) |
| 1 | 8282 (39.6) | 30 477 (36.9) | 2834 (37.3) | 17 573 (37.8) |
| ≥2 | 3584 (17.1) | 17 152 (20.8) | 1356 (17.9) | 9507 (20.4) |
| Educational level, y | 17 202 | 67 384 | 7185 | 41 751 |
| ≤9 | 563 (3.3) | 5403 (8.0) | 593 (8.3) | 6573 (15.7) |
| 10-12 | 4530 (26.3) | 25 046 (37.2) | 1197 (16.7) | 9033 (21.6) |
| >12 | 12 109 (70.4) | 36 935 (54.8) | 5395 (75.1) | 26 145 (62.6) |
| Household income, tertilea | NA | NA | 7315 | 44 032 |
| First | NA | NA | 2194 (30.0) | 14 922 (33.9) |
| Second | NA | NA | 2313 (31.6) | 14 803 (33.6) |
| Third | NA | NA | 2808 (38.4) | 14 307 (32.5) |
| Living with partner | 20 472 | 80 553 | 7464 | 45 743 |
| Yes | 19 287 (94.2) | 74 475 (92.5) | 7237 (97.0) | 43 877 (95.9) |
| Region of origin | 18 566 | 74 410 | 7583 | 46 446 |
| Scandinavia | 15 646 (84.3) | 52 341 (70.3) | 6492 (85.6) | 33 936 (73.1) |
| Middle East/Africa | 1196 (6.4) | 13 048 (17.5) | 138 (1.8) | 3552 (7.7) |
| Other European countries | 735 (4.0) | 5445 (7.3) | 481 (6.3) | 5476 (11.8) |
| Otherb | 989 (5.3) | 3576 (4.8) | 472 (6.2) | 3482 (7.5) |
| Condition associated with risk of complication of pregnancyc | 2775 (13.3) | 8702 (10.5) | 805 (10.6) | 4094 (8.8) |
| Asthma | 1855 (8.9) | 5795 (7.0) | 601 (7.9) | 3031 (6.5) |
| Cardiovascular disease | 380 (1.8) | 1274 (1.5) | 53 (0.7) | 289 (0.6) |
| Diabetes | 325 (1.6) | 900 (1.1) | 92 (1.2) | 301 (0.7) |
| Prior thrombosis | 204 (1.0) | 679 (0.8) | 15 (0.2) | 96 (0.2) |
| Chronic hypertension | 133 (0.6) | 405 (0.5) | 52 (0.7) | 280 (0.6) |
| Chronic kidney disease | 92 (0.4) | 344 (0.4) | 37 (0.5) | 283 (0.6) |
| Positive SARS-CoV-2 test resultd | ||||
| Only positive prior to start of pregnancy | 1138 (5.4) | 1944 (2.4) | 73 (1.0) | 273 (0.6) |
| Positive during pregnancy | 1390 (6.6) | 9733 (11.8) | 123 (1.1) | 1255(2.3) |
| Smoking in pregnancy | 20 208 | 79 695 | 6831 | 41 587 |
| Yes | 377 (1.9) | 2938 (3.7) | 280 (4.1) | 2330 (5.6) |
| Prepregnancy body mass index, median (IQR)e | 25 (22-29) | 24 (22-28) | 24 (22-27) | 24 (21-27) |
| SARS-CoV-2 vaccinef | ||||
| BNT162b2 | 16 726 (80.0) | 3698 (48.7) | ||
| mRNA-1273 | 3926 (18.8) | 3681 (48.5) | ||
| AZD1222 | 264 (1.3) | 211 (2.8) | ||
| SARS-CoV-2 vaccination status | ||||
| 1 dose | 4541 (21.7) | 2436 (32.1) | ||
| 2 doses | 16 375 (78.3) | 5154 (67.9) | ||
| Pregnancy trimester of SARS-CoV-2 vaccinationg | ||||
| First trimester | 654 (3.1) | 471 (6.2) | ||
| Second trimester | 10 519 (50.3) | 2493 (32.9) | ||
| Third trimester | 9743 (46.6) | 4625 (60.9) | ||
Abbreviation: NA, not available.
Household income was not available as part of the Swedish registry linkage.
The other category includes North America, South America, Latin America, Asia, Australia, and New Zealand.
These 6 conditions (asthma, cardiovascular disease, diabetes, prior thrombosis, hypertension, and kidney disease) are associated both with the likelihood of receiving vaccination and with the risk of an adverse pregnancy complication.
These are mutually exclusive categories.
Calculated as weight in kilograms divided by height in meters squared.
A total of 1753 women received 2 different vaccines during pregnancy. The frequencies shown in the table indicate the last type of vaccine the individual was given during pregnancy.
The trimester of vaccination against SARS-CoV-2 refers to the trimester when the individual received their first dose of the vaccine.