Table 3.
Hazard ratio of a COVID‐19 diagnosis in specialist healthcare services for pregnant women among 1 033 696 a women between 15 and 45 years of age in Norway
| Follow‐up period | Pregnancy status | Follow‐up time in days | All events | Excluding events where the end of pregnancy occurred within the hospital stay for COVID‐19 | |||
|---|---|---|---|---|---|---|---|
| No. of events | Hazard ratio (95% CI) | No. of events | Hazard ratio (95% CI) | ||||
| Unadjusted | Adjusted b | Adjusted b | |||||
| Complete follow‐up c | Non‐pregnant | 358 063 481 | 900 | 1.00 | 1.00 | 900 | 1.00 |
| Pregnant | 15 549 308 | 144 | 3.66 (3.07–4.36) | 3.46 (2.89–4.14) | 87 | 2.11 (1.68–2.64) | |
| 1st trimester | 5 479 349 | 36 | 2.63 (1.89–3.68) | 2.48 (1.77–3.47) | 24 | 1.67 (1.11–2.51) | |
| 2nd trimester | 5 813 675 | 28 | 1.86 (1.28–2.71) | 1.76 (1.20–2.57) | 27 | 1.71 (1.16–2.51) | |
| 3rd trimester | 4 256 284 | 80 | 7.53 (6.00–9.47) | 7.16 (5.68–9.01) | 36 | 3.25 (2.33–4.54) | |
| Wave 1 d | Non‐pregnant | 119 573 874 | 291 | 1.00 | 1.00 | 291 | 1.00 |
| Pregnant | 5 203 614 | 50 | 3.96 (2.93–5.34) | 3.32 (2.42–4.54) | 29 | 1.91 (1.29–2.82) | |
| 1st trimester | 1 748 663 | 12 | 2.93 (1.65–5.21) | 2.49 (1.39–4.46) | 7 | 1.44 (0.68–3.07) | |
| 2nd trimester | 1 943 283 | 7 | 1.43 (0.68–3.03) | 1.20 (0.56–2.55) | 7 | 1.19 (0.56–2.52) | |
| 3rd trimester | 1 511 668 | 31 | 8.50 (5.87–12.30) | 7.06 (4.81–10.35) | 15 | 3.38 (1.99–5.72) | |
| Wave 2 e | Non‐pregnant | 238 489 607 | 609 | 1.00 | 1.00 | 609 | 1.00 |
| Pregnant | 10 345 694 | 94 | 3.52 (2.83–4.37) | 3.53 (2.83–4.40) | 58 | 2.21 (1.69–2.91) | |
| 1st trimester | 3 730 686 | 24 | 2.51 (1.67–3.77) | 2.50 (1.65–3.78) | 17 | 1.80 (1.11–2.92) | |
| 2nd trimester | 3 870 392 | 21 | 2.06 (1.34–3.19) | 2.08 (1.34–3.23) | 20 | 2.01 (1.28–3.15) | |
| 3rd trimester | 2 744 616 | 49 | 7.03 (5.26–9.41) | 7.09 (5.30–9.47) | 21 | 3.09 (2.00–4.76) | |
a
Excluded three people in contact with specialist healthcare services for suspected or confirmed COVID‐19 disease before 1 March 2020.
b
Adjusted for age as a linear and squared term, country of birth, marital status, education, household income, diabetes, cerebrovascular disease, other cardiovascular disorders, immune deficiency, chronic lung disease, reduced immune function, neurological disorders, kidney failure, organ transplant, haematological cancer and other types of cancer.
c
1 March 2020–28 February 2021.
d
1 March 2020–30 June 2020.
e
1 July 2020–28 February 2021.