Table 2.
Sample Characteristics by Original MLS Exposure Groups
| Exposure*1 n = 374 (46.3%) |
Comparison* n = 434 (53.7%) |
p | |
|---|---|---|---|
| Maternal Characteristics | |||
| Race, minority | 319 (86.9%) | 370 (86%) | .719 |
| Low SES (Hollinghead 5), 1mo | 100 (28.1%) | 93 (21.6%) | .035 |
| Below poverty line, 1 mo | 232 (68.2%) | 252 (61.5%) | .054 |
| Married | 36 (9.7%) | 108 (24.9%) | < .001 |
| Education < high school | 197 (52.8%) | 299 (68.9%) | < .001 |
| No prenatal care | 79 (21.1%) | 10 (2.3%) | < .001 |
| Age | 30.42 (4.98) | 26.96 (5.93) | < .001 |
| Prenatal drug use (yes) | |||
| Cocaine | 346 (92.5%) | 0 (0%) | < .001 |
| Opiates | 58 (15.5%) | 0 (0%) | < .001 |
| Marijuana | 138 (36.9%) | 35 (8.1%) | < .001 |
| Alcohol | 270 (72.2%) | 217(50%) | < .001 |
| Nicotine | 300 (80.2%) | 122(%) | < .001 |
| Postnatal Environment | |||
| Postnatal drug use (yes) | |||
| Cocaine2 | 95 (25.4%) | 7 (1.6%) | < .001 |
| Opiates | 29 (7.8%) | 3 (.7%) | < .001 |
| Marijuana | 130 (34.8%) | 85 (19.6%) | < .001 |
| Alcohol | 326 (87.2%) | 341 (78.6%) | < .001 |
| Nicotine | 314 (84%) | 205 (47.2%) | < .001 |
| Domestic Violence, 5-12yr | 56 (15.2%) | 52 (12%) | .19 |
| Child abuse, 1mo-12yr, | 118 (31.6%) | 86 (19.8 %) | < .001 |
| # of caretaker Δ, 4 mo-12yr | 1.64 (1.82) | .39 (1) | < .001 |
| Newborn Medical Characteristics | |||
| Premature (yes) | 159 (42.6%) | 180 (41.6%) | .762 |
| Birth weight, g | 2,568.24 (776.85) | 2,656.05 (878.74) | .132 |
| Length, cm | 46.43 (4.81) | 46.82 (5.3) | .277 |
| Head circumference, cm | 31.97 (2.81) | 32.14 (3.23) | .432 |
| Male | 173 (46.3%) | 208 (47.9%) | .635 |
| Sleep Problems Index | |||
| Sleep Problems Index, 1m-12yr | 6.67 (5.65) | 6.5 (5.78) | .673 |
% or Mean (SD)
Participants were recruited to be in 1 of 2 groups: the group with exposure to cocaine or opiates or the comparison group that was matched on ethnicity, gender, and gestational age.
The decrease in cocaine use postnatally may be attributable to the fact that mothers using cocaine during pregnancy in some cohorts of the MLS (e. g., Providence) were required by state law to remain abstinent from cocaine in order to be reunified with their children. Either the mother remained abstinent from cocaine or the child was raised by a caregiver that reported abstinence from cocaine. Admitting postnatal cocaine use to our research team should not have been more threatening than admission of prenatal cocaine use. A National Institute on Drug Abuse Certificate of Confidentiality ensured confidentiality of the participant's drug use. The certificate superseded any mandatory reporting of illegal substance use and was explained in full to the mothers.