Table 2.
Characteristics of first trimester pregnant women who received at least one dose of mRNA COVID-19 vaccine.
| Characteristics * | Spontaneous Abortion (n = 124) | Ongoing Pregnancy (n = 803) | p-Value |
|---|---|---|---|
| Age | <0.001 | ||
| <35 | 52 (41.9%) | 490 (61.0%) | |
| ≥35 | 72 (58.1%) | 313 (39.0%) | |
| Weight ** | 0.004 | ||
| Normal (<25 kg/m2) | 64 (51.6%) | 521 (64.9%) | |
| Overweight (≥25 kg/m2) | 60 (48.4%) | 282 (35.1%) | |
| Gestational age | 0.358 | ||
| 1–6 weeks | 48 (38.7%) | 346 (43.1%) | |
| 7–13 weeks | 76 (61.3%) | 457 (56.9%) | |
| Vaccine | 0.779 | ||
| Pfizer BNT162b2 | 84 (67.7%) | 554 (68.9%) | |
| Moderna mRNA-1273 | 40 (32.3%) | 249 (31.1%) | |
| Number of doses | 0.232 | ||
| 1 | 17 (13.7%) | 120 (14.9%) | |
| 2 | 103 (83.1%) | 626 (77.9%) | |
| 3 | 4 (3.2%) | 57 (7.2%) | |
| Other vaccines given during 1st trimester | |||
| Tdap | 83 (66.9%) | 519 (64.6%) | 0.619 |
| HPV | 7 (5.6%) | 62 (7.7%) | 0.412 |
| Influenza | 42 (33.9%) | 271 (33.7%) | 0.978 |
| Chronic conditions *** | <0.001 | ||
| Yes | 23 (18.5%) | 40 (4.9%) | |
| No | 101 (81.5%) | 763 (95.1%) | |
| SARS-CoV-2 infection | 0.175 | ||
| Yes | 25 (20.1%) | 123 (15.3%) | |
| No | 99 (79.9%) | 680 (84.7%) | |
| Previous miscarriage | <0.001 | ||
| Yes | 29 (23.3%) | 73 (9.1%) | |
| No | 95 (76.7%) | 730 (90.9%) | |
| Smoking status | <0.001 | ||
| Smoker | 31 (25.0%) | 79 (9.8%) | |
| Non-smoker | 93 (75.0%) | 724 (90.2%) | |
| Abnormal uterine or cervical anatomy | 0.003 | ||
| Yes | 14 (11.3%) | 38 (4.7%) | |
| No | 110 (88.7%) | 765 (95.3%) | |
| Karyotype analysis (n = 37) | |||
| Normal | 26 (70.3%) | - | |
| Abnormal | 11 (29.7%) | - | |
| Assisted reproductive techniques | <0.001 | ||
| Yes | 21 (16.9%) | 9 (1.1%) | |
| No | 103 (83.1%) | 794 (98.9%) |
* Data reported as n (frequency) unless specified differently; ** Weight adjusted for gestational age; *** Chronic conditions include pregestational diabetes mellitus, cardiac disease, essential hypertension, respiratory disease, and autoimmune disease; karyotype analysis was performed by request to determine if the reason for spontaneous abortion was a genetic anomaly.