Table 2.

Studies describing correlations between intrapartum intravenous synOT exposure and postpartum depressive symptoms

							Results
Author, Year	Purpose#	Setting & Sample	Methods	Endogenous Oxytocin Measurement	Mood Measurement	synOT Measurement	Early Postpartum (≤ 6 weeks)	Late Postpartum (> 6 weeks)	Other	Newcastle-Ottawa quality score*
Gu et al. 2016	To examine the long-term effects of synOT administration on the endogenous oxytocin system and concomitant indices of functional status, specifically breastfeeding and emotional well being	n= 386 primarily community with some clinical in Quebec subsample of two larger studies (Zelkowitz et al. 2014 above)	Data collected at recruitment and in home at 2 months postpartum including demographics and breastfeeding status	ELISA (Enzo) Unextracted plasma diluted 1:2 or 1:4	EPDS GAD-8 Perinatal Posttraumatic Stress Questionnaire	Total intra and postpartum intravenous and intramuscular dose calculated from hospital records	29 women without any OT exposure (7.5% of sample)	At 2 months synOT was positively correlated with endogenous OT levels (p<.001). SynOT was significant predictor of EPDS score. Higher synOT was associated with greater PPD symptoms		7
Hinshaw et al., 2008	To test the hypothesis that early use of oxytocin reduces the need for caesarean delivery	n= 412 low risk nulliparous women with spontaneous term labor, diagnosis of primary dysfunctional labor	Randomized control trial. Active managementstarted synOT immediately after primary labor diagnosed, conservative management synOT withheld for 8 hours psychological assessment within 48 hours of delivery	None	EPDS	100% exposure to synOT. Dose and time of exposure differ on each arm	No significant difference in median EPDS scores or women scoring > 12 (depression cutoff in this study) between arms within 48 hours postpartum			n/a
Kroll-Desrosiers et al. 2017	To examine the relationship between peripartum synOT administration and the development of depressive and anxiety disorders within the first year PP	n= 46732 from Massachusetts Integrated Clinical Academic Research Database	Retrospective analysis from clinical data repository over nine years. Collected from birth to 1 year postpartum	None	Psychiatric diagnosis ICD-9 codes Psychotropic medications	Yes/no synOT exposure from hospital record	20% of deliveries with synOT exposure	Within women without any history of anxiety or depression, exposure increased risk by 32%; increased by 36% in women with a history of depression	50% of patients received PPD diagnosis within just over 2 months postpartum	7
Takacs et al., 2018	To explore both short- and long-term effects of intrapartum synOT on maternal mood	n= 260 community sample in Czech Republic	prospective longitudinal design data collection at the third trimester of pregnancy, 1-7 days, 6 weeks, and 9 months postpartum	None	EPDS Maternity Blues Questionnaire	Yes/no synOT exposure from hospital record	No effect of synOT on postpartum blues. Receiving synOT predicted a lower risk of positive PPD screen at 6 weeks PP (p=.014)	Receiving synOT significantly predicted a lower risk of positive PPD screen (EPDS > 12) at 9 months PP		8

^*0-2: low quality, 3-5: moderate quality, 6-8: high quality

^#purpose as defined in primary study

synOT= synthetic oxytocin (Pitocin); PPD= postpartum depression; EPDS= Edinburgh Postnatal Depression Scale; ELISA= enzyme-linked immunosorbent assay; ICD-9= International Classification of Diseases, 9^th revision