Table 1.
Summary of the included studies
| Study ID | Study design, country and time of realization | Participants | Intervention group | Control group | Main inclusion criteria | Exclusion criteria | Primary outcomes |
|---|---|---|---|---|---|---|---|
| Beharier 2021 [20] | Cohort, Jerusalem, between April 2020 and March 2021 | 1094 | Vaccinated group during pregnancy | Unvaccinated non infected controls | Age of 18 years or older and a willingness to participate and provide informed consent | Pregnant women with active maternal COVID-19 disease at delivery | |
| Blakeway 2021 [30] | Cohort, London, United Kingdom, between March 1, 2020, and July 4, 2021 | 1328 | At least 1 dose during pregnancy | Did not receive a vaccine during pregnancy | Pregnant women with known vaccination status and complete maternal and fetal outcome data | women who were vaccinated entirely (i.e., all doses) before pregnancy or after birth or women who had pregnancies complicated by fetal aneuploidy or genetic syndromes | COVID-19 vaccine uptake during pregnancy among women eligible for vaccination |
| Butt 2021 [31] | Case–control, Qatar, Between December 20, 2020, and May 30, 2021 | 2020 | PCR positive of Pregnant women | PCR negative of Pregnant women | All women presented to Hamad Medical Corporation between December 20, 2020, and May 30, 2021, with confirmed pregnancies | who were tested for SARS-CoV-2 by RT-PCR prior to pregnancy and those who had no SARS-CoV-2 testing done between December 20, 2020, and May 30, 2021 | overall vaccine effectiveness > 14 days after the second dose of the vaccine, we also determined vaccine effectiveness > 14 days after the first dose up to the date of the second dose |
| Collier 2021 [32] | Cohort, Jerusalem, from December 2020 through March 2021 | 103 | Pregnant Vaccinated women | Pregnant Unvaccinated and infected women | Pregnant, lactating, and non-pregnant women aged 18 to 45 years who were vaccinated or infected | _ | SARS-CoV-2 receptor binding domain binding, neutralizing, and functional non-neutralizing antibody responses from pregnant, lactating, and nonpregnant women were assessed following vaccination |
| Dagan 2021 [33] | Cohort Jerusalem, between 20 December 2020 and 3 June 2021 | 21,722 | Pregnant Vaccinated women | Pregnant Unvaccinated and infected women | Pregnancy, age of 16 years or older, continuous membership in CHS for 1 complete year, no previous positive SARS-CoV-2 PCR test, no previous SARS-CoV-2 vaccination, not residing in long-term care facilities | Individuals with missing data (only relevant for the body mass index and living area variables) | documented SARS-CoV-2 infection, symptomatic SARS-CoV-2 infection (COVID-19), COVID-19-related hospitalization; severe COVID-19, and COVID-19-related death |
| Kharbanda 2021 [35] | Cohort, USA, from December 15, 2020, through June 28, 2021 | 21,267 | Ongoing pregnancy periods (vaccinated women) | Spontaneous abortions (vaccinated women) | _ | _ | _ |
| Rottenstreich 2021 [36] | Cohort, Jerusalem, between January and April 2021 | 1775 | Covid‐19 vaccinated Pregnant women | Covid‐19 Unvaccinated Pregnant women | All women aged 18 years or older, with no documented previous positive PCR test, who delivered between 19 January 2021 (when the first vaccinated women gave birth) and 27 April 2021 | women with current or previous Covid‐19 disease | chorioamnionitis, postpartum hemorrhage, endometritis, blood transfusion, a cesarean delivery (CD), ICU admission, and a maternal hospital length of stay of > 5 days for vaginal delivery and > 7 days for CD |
| Shanes 2021 [37] | Cohort, USA | 200 | Pregnant Vaccinated women | Pregnant Unvaccinated women | _ | _ | _ |
| Theiler 2021 [38] | Cohort, USA | 2002 | Covid‐19 vaccinated Pregnant women | Covid‐19 Unvaccinated Pregnant women | All patients aged 16 to 55 years with a delivery event between December 10, 2020, and April 19, 2021, at a hospital within the Mayo Clinic Health System | Patients who opted out to use their medical records for research if their delivery occurred in Minnesota | (1) maternal death during hospitalization; (2) intrapartum neonatal death within 7 days of birth; (3) hypoxic-ischemic encephalopathy; (4) uterine rupture; (5) unplanned maternal ICU admission; (6) return to the operating room within 72 h of delivery; (7) postpartum hemorrhage with blood transfusion; (8) third- or fourth-degree laceration; (9) 5-min Apgar score of < 7; (10) admission to the neonatal ICU within 1 day of birth for > 1 day; or (11) neonatal birth trauma |
| Wainstock 2021 [39] | Cohort, Jerusalem, between January and June 2021 | 4,860 | Covid‐19 vaccinated Pregnant women | Covid‐19 Unvaccinated Pregnant women | _ | _ | _ |
| Pfizer BioNTech C4591001 | RCT | 37,706 | BNT162b2 (30 μg) | Placebo | _ | _ | vaccine efficacy |
| Moderna mRNA-1273-P301 | RCT | 30,418 | Moderna COVID-19 Vaccine mRNA-1273 | Placebo | _ | _ | _ |
| COV003 (Brazil) | RCT, Brazil | 6753 | ChAdOx1 nCoV-19 | MenACWY "control vaccine" (first dose), Saline (second dose) | Adults aged 18 years and older | _ | _ |