Table A2.

Newcastle - Ottawa Quality Assessment Scale for studies describing correlations between intrapartum intravenous synOT exposure and postpartum depressive symptoms

	Selection (score 0-3)		Comparability (score 0-2)	Outcome (0-1)
Author, year	Representativeness of exposed cohort	Assessment of exposure	Control for confounders	Assessment of outcome	Follow-up period after delivery	Adequacy of follow up	Total Score (0-8)
Gu et al. 2016	*Cases and controlled defined, fairly representative of community	*secure record: synOT dose calculated from hospital records; unextracted blood samples analyzed by ELISA	**Controlled for parity, age, marital status, years of education, sex of baby, and BF	*EPDS	*8 weeks	*Secondary analysis. Unlikely to introduce bias	7
Kroll-Desrosiers et al. 2017	*Representative of the average women in the community, very large sample size	*synOT exposure (yes/no) from hospital records	*Controlled for basic demographics	*Diagnosis or prescribed psychotropic medication	*1 year	*Database analysis. Unlikely to introduce bias	7
Hinshaw et al., 2008	n/a, see Table A3 for RoB	Assessment
Takacs et al., 2018	*Representative of the average healthy pregnant women in the community	**synOT exposure (yes/no) from hospital records	**Controlled for demographics, history of depression and multiple labor and delivery variables	*EPDS	*1-7 days, 6 weeks, 9 months	*Subjects lost to follow up unlikely to introduce bias. Provided description of lost subjects.	8

Total Score: 0-8; 0-2: low quality; 3-5: moderate quality; 6-8: high quality