Table 1.
Characteristics of the pregnancy cohort in the overall period, pre-vaccination era and vaccination era in England and Wales.
| Characteristic | Overall, N = 865,654 n (%) | Pre-vaccination era, N = 318,192 n (%) | Vaccination era, N = 162,733 n (%) |
|---|---|---|---|
| Age (years) | |||
| Median (interquartile range) | 30 (26–34) | 30 (26–33) | 30 (26–34) |
| <30 | 403,318 (46.6) | 152,268 (47.9) | 73,590 (45.2) |
| 30–39 | 434,849 (50.2) | 156,033 (49) | 83,577 (51.4) |
| ≥40 | 27,487 (3.2) | 9891 (3.1) | 5571 (3.4) |
| Deprivation | |||
| 1 (least) | 214,763 (24.8) | 79,462 (25.5) | 39,026 (24) |
| 2 | 190,090 (22) | 69,368 (22.3) | 35,473 (21.8) |
| 3 | 167,387 (19.3) | 60,019 (19.3) | 31,411 (19.3) |
| 4 | 152,663 (17.6) | 53,482 (17.2) | 29,464 (18.1) |
| 5 (most) | 136,868 (15.8) | 47,612 (15.3) | 26,557 (16.3) |
| Unknown | 3883 (0.4) | 1428 (0.5) | 807 (0.5) |
| Ethnic group | |||
| Black or Black British | 40,784 (4.7) | 15,018 (4.7) | 7745 (4.8) |
| Asian or Asian British | 105,156 (12.1) | 38,979 (12.3) | 19,624 (12.1) |
| White | 647,493 (74.8) | 236,290 (74.3) | 122,260 (75.1) |
| Mixed | 19,219 (2.2) | 6885 (2.2) | 3752 (2.3) |
| Ethnic minorities | 39,968 (4.6) | 15,593 (4.9) | 6953 (4.3) |
| Unknown ethnic group | 13,029 (1.5) | 5427 (1.7) | 2399 (1.5) |
| Previous pregnancy | 551,787 (63.7) | 201,725 (63.4) | 102,611 (63.1) |
| COVID-19 diagnosis during pregnancy | 60,134 (6.9) | 6821 (2.1) | 17,260 (10.6) |
| COVID-19 Hospitalization | 3626 (0.4) | 451 (0.1) | 1292 (0.8) |
| Trimester of exposure | |||
| 1st | 11,250 (1.3) | 175 (0.1) | 3197 (2) |
| 2nd | 18,532 (2.1) | 673 (0.2) | 5558 (3.4) |
| 3rd | 30,352 (3.5) | 5973 (1.9) | 8505 (5.2) |
| Dose 1 of COVID-19 vaccine during pregnancy | 62,478 (7.2) | 70,614 (43.4) | |
| Dose 2 of COVID-19 vaccine during pregnancy | 98,977 (11.4) | 50,133 (30.8) | |
| Smoking status | |||
| Current | 152,078 (17.6) | 57,780 (18.2) | 27,702 (17) |
| Ex | 118,843 (13.7) | 43,708 (13.7) | 22,070 (13.6) |
| Never | 542,178 (62.6) | 196,999 (61.9) | 102,486 (63) |
| History of cardiovascular and haematological diseasesa | 9590 (1.1) | 3500 (1.1) | 1822 (1.1) |
| History of hypertensiona | 84,740 (9.8) | 28,661 (9) | 17,558 (10.8) |
| History of diabetesa | 44,549 (5.1) | 15,966 (5) | 8721 (5.4) |
| History of depressiona | 178,352 (20.6) | 64,645 (20.3) | 34,429 (21.2) |
| History of other conditionsa | 131,338 (15.2) | 54,043 (17) | 17,848 (11) |
a
In the year before pregnancy.