Table 1.
Comparison of the baseline and pregnancy characteristics between women who received at least 1 dose of the COVID-19 vaccine during pregnancy and those who did not
| Variables | At least 1 dose during pregnancy (n=140) | Did not receive a vaccine during pregnancy (n=1188) | P valuea |
|---|---|---|---|
| Vaccine typeb | |||
| Pfizer-BioNTech (mRNA) | 109 (77.8) | — | NA |
| Moderna (mRNA) | 18 (12.9) | — | NA |
| Oxford-AstraZeneca (viral vector) | 13 (9.3) | — | NA |
| Vaccination-birth interval (d) | 32.3 (20.2–53.4) | — | NA |
| Trimester at vaccination | |||
| First trimester | 0 (0.0) | — | NA |
| Second trimester | 20 (14.3) | — | NA |
| Third trimester | 120 (85.7) | — | NA |
| Maternal age (y) | 35.0 (31.7–37.0) | 33.0 (30.0–36.0) | .005 |
| Parous | 62 (44.3) | 593 (49.9) | .207 |
| IMD score | 18.9 (14.0–23.7) | 20.2 (14.3–27.6) | .009 |
| IMD quintile | |||
| First quintile | 17 (12.1) | 101 (8.5) | .152 |
| Second quintile | 17 (12.1) | 166 (14.0) | .552 |
| Third quintile | 47 (33.6) | 368 (31.0) | .531 |
| Fourth quintile | 50 (35.7) | 422 (35.5) | .964 |
| Fifth quintile | 5 (3.6) | 102 (8.6) | .039 |
| Not available | 4 (2.9) | 29 (2.4) | .764 |
| Self-reported ethnicity | |||
| White | 80 (57.1) | 551 (46.4) | .015 |
| Asian | 17 (12.1) | 205 (17.3) | .125 |
| Afro-Carribean | 5 (3.6) | 101 (8.5) | .041 |
| Mixed | 13 (9.3) | 156 (13.1) | .196 |
| Not reported | 25 (17.9) | 175 (14.7) | .327 |
| BMI (kg/m2) | 23.8 (21.5–27.5) | 24.2 (21.8–28.3) | .344 |
| Obesity (BMI ≥30 kg/m2) | 15 (10.7) | 173 (14.6) | .216 |
| Smoker | 1 (0.7) | 27 (2.3) | .224 |
| Alcohol use | 1 (0.7) | 5 (0.4) | .624 |
| Pregestational diabetes mellitus | 6 (4.3) | 7 (0.6) | <.001 |
| Antenatal medication | 46 (32.9) | 273 (23.0) | .009 |
| Hypertension on medication | 13 (9.3) | 46 (3.9) | .003 |
| Twin pregnancy | 4 (2.9) | 24 (2.0) | .514 |
| Antenatal complications | |||
| SARS-CoV-2 infection | 2 (1.4) | 16 (1.3) | .936 |
| Gestational diabetes mellitus | 20 (14.3) | 146 (12.3) | .499 |
| Obstetrical cholestasis | 2 (1.4) | 12 (1.0) | .646 |
| Cardiac problems | 1 (0.7) | 10 (0.8) | .874 |
| Any | 25 (17.9) | 175 (14.7) | .327 |
Data are presented as number (percentage) or median (interquartile range), unless otherwise indicated.
BMI, body mass index; IMD, index of multiple deprivation; mRNA, messenger RNA; NA, not applicable.
Blakeway et al. COVID-19 vaccination during pregnancy. Am J Obstet Gynecol 2022.
Wilcoxon signed-rank test, t test, or chi-square test was used, as appropriate
According to the United Kingdom Joint Committee on Vaccination and Immunisation guidance on April 16, 2021, it was preferable for pregnant women to be offered the Pfizer-BioNTech or Moderna vaccines when available (https://www.gov.uk/government/news/jcvi-issues-new-advice-on-covid-19-vaccination-for-pregnant-women).