Table 3.
Effects of different types of COVID-19 vaccine on pregnancy.
| References | Study design | Vaccine type | Sample size | History of SARS CoV-2 infection | Timing of vaccination | Control | Main outcomes | |
|---|---|---|---|---|---|---|---|---|
| 1 | [74] | Retrospective cohort study | mRNA vaccine | 3958 pregnant women | 2.0% infected | First dose: 2.3% in Ta, 28.6% in Tb, 43.3% in Tc, 25.7% in Td | Incidences reported before the Covid-19 pandemic | No significant differences |
| 2 | [26] | Prospective cohort study | mRNA vaccine | 894 pregnant women | Unknown | First dose: 3.6% in T0, 4.5% in T1, 69.7% in T2 and 22.3% in T3 | Incidences reported before the Covid-19 pandemic | No significant differences |
| 3 | [13] | Prospective cohort study | mRNA vaccine | 313 pregnant women | 7.4% infected | First dose: 30% in Tα, 46% in Tβ, 24% in Tγ | Unvaccinated group | No significant differences |
| 4 | [28] | Retrospective cohort study | 99.8% mRNA vaccine, 0.2% unknown | 97590 pregnant women | 3.4% infected | First dose: 0.9% in Tα, 35.5% in Tβ, 63.6% in Tγ | Unvaccinated group | No significant differences |
| 5 | [77] | Retrospective cohort study | 99.3% mRNA vaccine, 0.7% viral vector vaccine | 2002 pregnant women | 10.6% infected | First dose: a median of 32 weeks; Completed vaccination: a median of 35 weeks | Unvaccinated group | No significant differences |
| 6 | [55] | Retrospective cohort study | 98.3% mRNA vaccine, 1.7% viral vector vaccine | 157521 pregnant women | 10.1% infected | First dose: 3.9% in T0 + T1, 45.6% in T2, 50.4% in T3 | Unvaccinated group | No significant differences |
| 7 | [79] | Retrospective cohort study | mRNA vaccine | 4399 pregnant women | None infected | First dose: a mean of 7.5 weeks before delivery second dose: 5.4 weeks before delivery | Unvaccinated group | No significant differences (subgroup analysis: two doses of vaccines were associated with longer gestational weeks and higher newborn birth weight) |
| 8 | [51] | Retrospective cohort study | 95.8% mRNA vaccine, 4.2% viral vector vaccine | 46079 pregnant women | 3.4% infected | First dose: 1.7% in Tα, 36.5% in Tβ, 61.8% in Tγ | Unvaccinated group | No significant differences |
| 9 | [28] | Retrospective cohort study | 99.7% mRNA vaccine, 0.3% unknown | 85162 pregnant women | 3.9% infected | First dose: 12.1% in Ta + Tb, 48.1% in Tc, 39.8% in Td | Unvaccinated group | No significant differences |
| 10 | [60] | Retrospective cohort study | mRNA vaccine | 15865 pregnant women | 4.0% infected | Unknown | Unvaccinated group | Receipt of the mRNA vaccine was associated with a lower rate of several adverse pregnancy outcomes |
| 11 | [17] | Retrospective cohort study | mRNA vaccine | 3094 pregnant women | 11.0% infected | First dose: All in the first trimester | Unvaccinated group | No significant differences |
| 12 | [15] | Retrospective cohort study | Inactivated vaccine | 2091 FET women | None infected | First dose: Between obtaining embryos and achieving pregnancy | Unvaccinated group | No significant differences |
| 13 | [53] | Prospective cohort study | Inactivated vaccine | 967 pregnant women with natural conception | None infected before the first trimester | First dose: All in Ta + Tb | Unvaccinated group | No significant differences |
| 14 | [48] | Prospective cohort study | Inactivated vaccine | 253 pregnant women | Unknown | First dose: 71% within 3 months before their LMP and 39% after LMP | Unvaccinated group | No significant differences |
| 15 | [55] | Retrospective cohort study | 98.3% mRNA vaccine, 1.7% viral vector vaccine | 157521 pregnant women | 10.1% infected | First dose: 3.9% in T0 + T1, 45.6% in T2, 50.4% in T3 | Unvaccinated group | No significant differences |
| 16 | [12] | Retrospective cohort study | 90.7% mRNA vaccine, 9.3% viral vector vaccine | 1328 pregnant women | 1.4% infected | First dose: 14.3% in T2, 85.7% in T3 | Unvaccinated group | No significant differences |
| 17 | [4] | Retrospective cohort study | 88.3% mRNA vaccine, 11.7% viral vector vaccine | 264927 pregnant women | Unknown | First dose: 78.8% in Ta + Tb + Tc, 21.2% in Td | mRNA vaccine group | Obstetric outcomes of pregnant women appeared to be worse with the viral vector vaccine than with the mRNA vaccine |
Ta, within 30 days before last menstrual period; Tb, <14 weeks of gestation; Tc, ≥14 and <28 weeks of gestation; Td, ≥28 weeks of gestation; T0, 7 days before last menstrual period to 13 days after last menstrual period; T1, 14 days after last menstrual period and <12 weeks of gestation; T2, ≥12 and <28 weeks of gestation; T3, ≥28 weeks of gestation; Tα, from pre-conception to13 weeks of gestation; Tβ, 14–28 weeks of gestation; Tγ, 29 weeks of gestation till birth; LMP, last menstrual period; FET, frozen embryo transfer.