PROVIDENCE, R.I.--Crack-smoking pregnant women give birth to babies who twitch, tremble and arch their backs more than non-exposed newborns, according to a new study by researchers in the Brown University School of Medicine.
"Crack babies" also display patterns of both excitability and lethargy, appear to be more stressed, and fail to follow certain stimuli, such as a rattle or bell, compared to non-exposed infants.
The Brown researchers think the findings result from the combined action of cocaine with alcohol and marijuana. Alcohol can boost the effects of cocaine, and most of the crack-smoking women in the study abused alcohol and marijuana.
The Brown study injects clear-cut evidence into a two-decade-old medical debate over what happens to newborns whose mothers smoke crack cocaine during pregnancy. Its testing procedure was developed by the Brown researchers as part of an ongoing, long-term multisite study, sponsored by the National Institutes of Health, of about 1,400 infants and children. Given that studies of crack babies in the 1980s produced conflicting findings and were biased at times by unscientific techniques, the Brown study is designed to provide scientifically valid findings about the effects of substance exposure in the womb.
"Newborns who were exposed to crack looked like normal babies but didn't act like them," said Beata Napiorkowski, the lead author of the Brown study, which appears in the July issue of the journal Pediatrics. "Cocaine-exposed infants were more jittery, had more muscle tension, and were harder to move because they were stiff." Some cocaine-exposed infants were also drowsier and had a weaker crawl than non-exposed babies.
Napiorkowski and co-researchers in the Department of Pediatrics in Women and Infants Hospital studied the one- and two-day-old babies of 57 women. Twenty of the infants had been exposed to cocaine, alcohol, marijuana and cigarettes. Seventeen of the newborns had been exposed to alcohol and/or marijuana and cigarettes. The other 20 infants were drug free, but some of their mothers smoked cigarettes.
Mothers in the study were granted confidentiality, which exempted the researchers from reporting their drug use. All of the mothers received prenatal care and all of the babies were normal birth weight.
The study offers some encouraging news. In contrast to anecdotal reports, the babies are no more difficult to test than non-exposed infants and don't require special handling or consoling, the researchers said.
"From this study, we've also learned that cocaine exposure in the womb may not produce newborns with hemorrhages, lesions and brain damage, as reported elsewhere," said Barry Lester, professor of pediatrics and psychiatry and one of the study's authors. "These are fragile, vulnerable babies. With the proper child rearing, they will do fine. If the resources are available, it's possible to intervene with drug-abusing moms early in their pregnancies to try and produce optimal newborns."
However, Lester said that the newborns of most crack-using mothers are likely reared in environments of poverty, violence and poor parenting. Babies that twitch, cry or act fussy can further influence how parents treat the baby.
"A baby that isn't cuddly sweet can turn off a parent," Lester said. "For a drug-using mom, this is a real setup for failure, as problems with the baby and mother can trigger negative parenting. The trick is to get the mothers back on track, with parenting, psychiatric and addiction counseling."