Table 1.

Maternal treatment and substance exposure characteristics (n=49)

	Mean	SD	Range
Maternal substance history:
Age at first substance use (years)	19.8	4.8	(9–31)
Age at regular (3x/week or more), substance use (years)	21.0	4.6	(14–32)
Duration regular substance use upon treatment entry (years)	6.5	4.4	(1–22)
Treatment measures:
Gestational age upon treatment entry (weeks)	21.3	7.0	(5.3–32.5)
Length of time in treatment prior to delivery (days)	121.1	56.7	(29–241)
Buprenorphine dose (mg)
At 24 weeks gestation (n=20)	12.0	7.1	(2–28)
At 28 weeks gestation (n=30)	12.3	6.0	(2–24)
At 32 weeks gestation (n=42)	12.7	6.3	(2–24)
At 36 weeks gestation (n=40)	12.8	6.5	(2–24)
Urine toxicology screenings during treatment	16.4	8.0	(3–33)
Positive research urine toxicology screenings* at delivery (%/ SD)	19.7	25.6	(1–100)
Participants with 1 or more positive screenings (#/%)	29	(59%)

^*substance screened for include (#/%): opiates (12;41%), THC (10; 34%), benzodiazepines (11;38%), cocaine (8;28%), opioid containing pain relievers (6;21%), methadone (4;14%), methamphetamine (2;7%), amphetamines (1;3%), barbiturates (0;0%) and buprenorphine (49; 100%)

Cut off values for urine toxicology screenings: opiates (morphine) (300 ng/mL); THC (50 ng/mL); benzodiazepines (300 ng/mL); cocaine (300 ng/mL); opioid containing pain relievers (100 ng/mL); methadone (300 ng/mL); methamphetamine (500 ng/mL); amphetamines (1000 ng/mL); barbiturates (300ng/mL), and buprenorphine (10 ng/mL)