Table 1 Characteristics of included studies
Authors | Country | Setting | Study design | Dates of recruitment | Participants Inclusion (I)/Exclusion (E) | Intervention Exposure | Comparisons | N | Outcomes |
|---|---|---|---|---|---|---|---|---|---|
Abu Raya [26] | Israel | Hospital In−/outpatients not specified | PCS | 2013–2014 | I: pregnant women with singleton births at gestational age ≥ 36 weeks E: pregnant women with a newborn <2000 g; immunologic disorder; immunoglobulins in the previous year; immunosuppressive drugs in the current pregnancy; pertussis infection or pertussis-containing vaccine within 5 years or any vaccine besides Tdap within 2 weeks of delivery. | Tdap ≥20 weeks’ gestation | No Tdap during pregnancy | 81 | Anti-pertussis antibodies in mothers’ and infants’ sera measured by ELISA |
Abu Raya [27] | Israel | Same as above | PCS | 2013–2014 | I: pregnant women with singleton births; gestational age ≥ 36 weeks; intending to breast feedE: same as Abu Raya et al. [26] | Tdap ≥20 weeks’ gestation | No Tdap during pregnancy | 37 | Anti-pertussis antibodies in breast milk measured by ELISA |
Dabrera [37] | UK | Community- based data | CCS | 2012–2013 | E: any potentially confounding protective effect from active immunisation. | Any pertussis-containing vaccine at any time in pregnancy | No pertussis-containing vaccine during pregnancy | 113 | Pertussis infection in infants; pertussis related complications as measured by the length of hospital stay in infants |
De Schutter [28] | Belgium | Hospitals In−/outpatients not specified | PCS | 2013–2014 | E: Women who delivered prematurely, who had received another vaccine or any blood product in the previous month. | Tdap during the 2nd or 3rd trimester | No Tdap during pregnancya | 28a | Anti-pertussis antibodies in breast milk measured by ELISA |
Donegan [32] | UK | Community- based data | RCS | 2012–2013 for vaccine group/ 2010–2012 for control group | I: women aged ≥12 who had a pertussis-containing vaccination during pregnancy and at least 28 days of follow-up data after vaccination | Any pertussis vaccine at any time during pregnancy | No pertussis-containing vaccine during pregnancy | 38,900 | Obstetric and perinatal complications |
Gall [5] | US | Hospital In−/outpatients not specified | RCS | 2008–2009 | I: pregnant women who had been admitted to the hospital at the study site and their babies | Tdap at any time during pregnancyb | No Tdap during pregnancy | 104 | Anti-pertussis antibodies in infants’ sera measured by ELISA |
Hardy-Fairbanks [33] | Not specifiedc | Not specifiedb | PCS | 2006 for vaccine group/ 2008–2009 for control group | E: Women with multiple gestations; serious underlying health issues in either the mother or infant, preterm infants, or infants who needed transfusions or who had been advised not to have blood drawn for health reasons | Tdap at any time during pregnancy | No Tdap during pregnancy | 70 | Anti-pertussis antibodies in mothers’ and infants’ sera measured by ELISA |
Healy [34] | US | Hospital In−/outpatients not specified | RCS | 2009–2011 | I: Women who delivered at ≥37 weeks’ gestation; received Tdap within 2 years; and had plasma–serum pairs available | Tdap at any time during pregnancy | Tdap before pregnancy | 105 | Anti-pertussis antibodies in mothers’ and infants’ sera measured by ELISA |
Hoang [30] | Vietnam | Community | RCT | 2012–2013 | I: Women aged 18–41 with low risk for complications.E: Women with: any serious underlying medical condition; febrile illness in the 72 h before injection, receipt of TT vaccine in the past month; receipt of Tdap in the past 10 years; receipt of a vaccine, blood product or experimental medicine in the 4 weeks before or after injection; previous severe reaction to any vaccine | Tdap, 20–30 weeks’ gestation | TT during pregnancy | 103 | Anti-pertussis antibodies in mothers’ and infants’ sera measured by ELISA; vaccine-related adverse outcomes; obstetric and perinatal complications. |
Kharbanda [24] | US | Community- based data | RCS | 2010–2012 | I: Women with singleton pregnancies with a live birth E: women with live virus vaccines during pregnancy; Tdap in the 7 days after the estimated pregnancy start date or in the 7 days before delivery; incomplete birth data | Tdap at any time during pregnancyd | No Tdap during pregnancy | 123,494 | Obstetric and perinatal complications |
Kharbanda [25] | US | Community- based data | RCS | 2007–2013 | Same as Kharbanda et al. [24] | Tdap at any time during pregnancyd | No Tdap during pregnancy | 163,138 | Obstetric complications occurring within 42 days of vaccination. |
Ladhani [35] | UK | Community- based data | RCS | 2012–2014 for vaccine group/ 2011–2012 for control group | I: Any infant eligible for the national immunisation program | Tdap-IPV | No pertussis -containing vaccine during pregnancy | 387 | Antibody responses after primary immunisation in infants’ sera measured by ELISA. |
Maertens [29] | Belgium | Hospitals In−/outpatients not specified | PCS | 2012–2014 | I: Women aged 18–40 with low risk for complications. E: same as Hoang et al. [30] | Tdap at 22–33 weeks’ gestation | No pertussis-containing vaccine during pregnancy | 99 | Anti-pertussis antibodies in mothers’ and infants’ sera measured by ELISA; obstetric complications |
Munoz [31] | US | NIH Vaccine Treatment Evaluation Unit | RCT | 2008–2012 | I: Women aged 18–45 with no underlying chronic medical conditions, a singleton, uncomplicated pregnancy with normal first- or second-trimester screening test results E: Women who received Tdap or any tetanus-containing vaccine within the prior 2 years | Tdap at 30–32 weeks’ gestation | Placebo | 45 | Anti-pertussis antibodies in mothers’ and infants’ sera measured by ELISA; vaccine-related adverse outcomes; perinatal complications; pertussis infection in infants |
Shakib [36] | US | Healthcare database | RCS | 2005–2009 | I: Pregnant women 12–45 years of age and their babies E: Women who had documentation of Tdap vaccine within 3 days prior to the delivery outcome | Tdap at any time during pregnancy | No Tdap during pregnancy | 690 | Pertussis infection in infants; perinatal complications |