Relative risk of outcomes comparing COVID-19 cases (symptomatic cases only) versus COVID-negative pregnancies
|
Outcome | Studies (n) | Included studies*† | Symptomatic RR (95% CI) |
| ICU admission | 8 | c d e1* e2 f h j k | 4.88 (2.57 to 9.27) |
| Ventilation | 7 | c d e1* e2 f h j | 24.09 (6.85 to 84.77) |
| Critical care | 7 | c d e1* e2 f h j* | 8.47 (3.37 to 21.28) |
| Pneumonia | 6 | c e1* e2 f h j* | 34.58 (3.36 to 356.13) |
| Maternal death | 10 | a* c* d* e1* e2* f* g h i j* | 8.48 (1.70 to 42.21) |
| Haemorrhage | 6 | a c g h i k | 1.30 (0.81 to 2.10) |
| Placental abruption | 5 | a f h j* k | 2.08 (0.95 to 4.53) |
| Hypertensive disorders of pregnancy (diagnosed at or after COVID-19) | a b j | 1.74 (1.01 to 3.00) | |
| Hypertensive disorders of pregnancy (diagnosed at any time) | 10 | a b c e1 e2 g h i j k | 1.28 (1.03 to 1.59) |
| Pre-eclampsia | 9 | a b d e1 e2 f i j k | 1.58 (1.20 to 2.08) |
| Eclampsia | 7 | a* b* e1* e2* i j* k* | 1.07 (0.05 to 22.17) |
| Pre-eclampsia or eclampsia | 10 | a b c e1 e2 g h i j k | 1.63 (1.26 to 2.11) |
| Thromboembolic disease | 8 | a c d* e1* e2* g* i* j* | 9.64 (1.69 to 54.97) |
| Preterm labour | 6 | c e1* e2 g i j | 1.87 (1.06 to 3.32) |
| Preterm labour (COVID-19 onset <37 weeks) | 4 | c g i j | 2.71 (1.25 to 5.85) |
| Caesarean section | 10 | a c d e1 e2 g h i j k | 1.16 (1.04 to 1.29) |
| Intrapartum C-section | 8 | a c e1* e2 g h i j | 1.27 (1.06 to 1.52) |
| Stillbirth | 12 | a b c d* e1 e2 f g h i j* k | 1.35 (0.62 to 2.96) |
| Perinatal death | 9 | a c d e1 e2 f g i j* | 1.45 (0.62 to 3.43) |
| Early neonatal death | 9 | a c d e1 e2* f g i j* | 1.89 (0.61 to 5.9) |
| Neonatal death | 10 | a c d e1 e2* f g h i j* | 1.93 (0.71 to 5.25) |
| NICU admission at birth | 7 | a c d e2 f g j | 2.12 (1.31 to 3.43) |
| Very low birth weight (<1500 g) | 12 | a b c d e1 e2 f g h i j* k | 1.67 (1.07 to 2.62) |
| Low birth weight (<2500 g) | 12 | a b c d e1 e2 f g h i j k | 1.32 (1.09 to 1.59) |
| Small for gestational age (3rd) | 12 | a b c d e1 e2 f g h i j k | 1.22 (0.86 to 1.71) |
| Small for gestational age (10th) | 12 | a b c d e1 e2 f g h i j k | 1.05 (0.85 to 1.30) |
| Moderate preterm birth (<34 weeks) | 12 | a b c d e1 e2 f g h i j k | 1.62 (1.20 to 2.17) |
| Moderate preterm birth (<34 weeks) (COVID-19 onset <34 weeks)‡ | 7 | b c d g i j k | 3.12 (1.94 to 5.02) |
| Preterm birth (<37 weeks) | 12 | a b c d e1 e2 f g h i j k | 1.41 (1.15 to 1.73) |
| Preterm birth (<37 weeks) (COVID-19 onset <37 weeks)‡ | 7 | b c d g i j k | 1.70 (1.22 to 2.36) |
*Included studies for each estimate are categorised as follows: (a) Ahlberg et al, Sweden19; (b) Akelo and Tippett Barr (2021), Kenya; (c) Bevilacqua and Laurita Longo (2020), Italy; (d) Brandt (2020), New Brunswick, USA; (e1) Crovetto (2020), Spain, Cohort I; (e2) Crovetto (2020), Spain, Cohort II; (f) Kalafat et al, Turkey22; (g) Le Doare (2021), Uganda; (h) Nachega (2021), Multi-country Africa; (i) Nunes (2021), South Africa; (j) Poon (2021), China-Hong Kong; (k) Sakowicz (2021), Chicago, USA.
†Asterisks indicate there is zero total event for a given study. These studies are not included in the ‘Events/Total’ and pooled risk estimates.
‡These outcomes (preterm labour, moderate preterm birth before 34 weeks’ gestation and preterm birth before 37 weeks’ gestation) were included in the sensitivity analyses where we restrict COVID-19 cases to those with confirmed onset prior to 37 weeks’ gestation (or 34 weeks for moderate preterm birth). The full comparison group is used for each of the sensitivity analyses.
C-section, caesarean section; ICU, intensive care unit; NICU, neonatal intensive care unit; RR, relative risk.