pcb Cleary 2014.

Methods	Cohort study. At the time of 2009‐10 pandemic, the monovalent pH1N1 was offered to pregnant women and other at‐risk groups by the Health Service Executive. Pregnancy outcomes were evaluated in women vaccinated during pregnancy and those not vaccinated during pregnancy.
Participants	Women who delivered at the Coombe Women and Infants University Hospital (Dublin) between December 2009 and September 2010 and who reported having been vaccinated (n = 2996). The control consists of women who delivered during the same time interval at the same hospital but who reported not having received influenza vaccination (n = 3898). A second historical control group includes all women who delivered during a time interval (December 2008 to September 2009) before the mass vaccination and the main wave of the 2009‐10 pandemic (n = 7044, not considered for the analysis).
Interventions	Vaccine exposure was ascertained by means of the delivery suite admission form, which contained the following questions: H1N1 vaccine this pregnancy (Y/N) When given (I; II, III trimester) Vaccine used? (Celvapan 1 to 2 doses, Pandremix, unknown) Any exposure at any time during pregnancy is considered for analysis purposes.
Outcomes	Data on maternal characteristics, medical and obstetric history recorded at the antenatal booking interview, and perinatal outcomes recorded in the delivery suite and neonatal intensive care unit were extracted from electronic hospital records. Preterm birth < 37 weeks Spontaneous birth < 37 weeks Very preterm birth < 32 weeks Spontaneous birth < 32 weeks Small for gestational age: birth weight determined to be less than the 10th centile customised for maternal weight, height, gestation, and infant sex, age Apgar score < 3 at 1 min Apgar score < 7 at 5 min Admitted to neonatal unit Congenital anomaly: ascertained from electronic records of any anomalies identified by midwifery or paediatric staff on the delivery suite or from congenital anomaly, body system or discharge diagnoses fields in the neonatal unit electronic discharge records Perinatal death (within 7 days of life)
Notes	Funding source ‐ government BC was funded by the charity Friends of the Coombe and the School of Pharmacy, Royal College of Surgeons in Ireland. Exposure: about 56.5% of vaccinated women reported having received Celvapan (not adjuvanted), 23% Pandremix (AS03 adjuvanted), and 20% were unsure about the specific vaccine used.
Risk of bias
Bias	Authors' judgement	Support for judgement
PCS/RCS ‐ selection exposed cohort All outcomes	Low risk	All women who delivered at the Coombe Women and Infants University Hospital between December 2009 and September 2010 and received influenza vaccine during pregnancy
PCS/RCS ‐ selection non‐exposed cohort All outcomes	Low risk	Drawn from the same source as the exposed cohort
PCS/RCS ‐ comparability All outcomes	Low risk	Characteristics that differ significantly between exposed and not exposed group have been taken into account for effect measure calculation.
PCS/RCS ‐ assessment of outcome All outcomes	Low risk	Hospital records
Summary assessment	Low risk	Low risk of bias