Table 1.

Characteristics of included studies and participant demographics.

Author, Year	Setting	Number of Participants	Demographics
Debelak et al., 2013 [12]	Outpatient substance abuse and mental health facility Michigan, USA	Bup-nlx group: n = 10 8 initiated pre-pregnancy 2 initiated during first trimester No comparison group	Mean age: 26 years White: 90% High school: 60% Single: 90%
Dooley et al., 2016 [17]	Outpatient multidisciplinary obstetric program Ontario, Canada	Bup-nlx group: n = 30 30 initiated pre-pregnancy 5 continued for entire pregnancy Comparison groups: Other opioids n = 134 No opioids n = 476	Mean age: 26 years Mean gravidity: 4 Mean parity: 2 Higher gravidity and parity in bup-nlx group compared to non- exposed group *
Gawronski et al., 2014 [15]	Academic medical center Ohio, USA	Bup-nlx group: n = 58 Comparison group: Methadone n = 92	Mean age: 27 years White: 95% High school: 31% No significant differences between groups
Jumah et al., 2016 [18]	Community-based outpatient Treatment program Ontario, Canada	Bup-nlx group: n = 62 51 initiated pre-pregnancy 11 initiated during pregnancy 48 switched to monoproduct Comparison groups: Illicit opioids n = 159 No opioids n = 618	Mean age: 26 years Mean gravidity: 4 Indigenous: 85% High school: 16% Higher gravidity in bup-nlx group compared to non-exposed group *
Mullins et al., 2020 [14]	Community-based perinatal substance use disorders program North Carolina, USA	Bup-nlx group: n = 85 Comparison group: Bup-monoproduct: n = 108	Mean age: 28 years White: 89% Primiparous: 26% No significant differences between groups
Nguyen et al., 2018 [13]	Outpatient treatment program For pregnant women with opioid use disorder West Virginia, USA	Bup-nlx group: n = 26 No comparison group	Mean age: 28 years White: 89% Single: 60% Mean parity: 2
Wiegand et al., 2015 [16]	Residential and outpatient women’s substance use disorder treatment program North Carolina, USA	Bup-nlx group: n = 31 Comparison group: Methadone n = 31	Mean age: 27 years White: 81% Single: 87% Mean high school educated Primiparous: 26% No significant differences between groups

Bup-nlx: buprenorphine-naloxone; bup-mono: buprenorphine monoproduct; USA: United States of America; * indicates statistical difference (p < 0.05)