Prenatal cocaine exposure exerts subtle effects on
Melanie Fridl Ross
GAINESVILLE, Fla. - Children exposed to cocaine before birth show subtle but discernible differences in their ability to plan and problem-solve once they reach school age, University of Florida researchers report.
Still, most fare far better in the first few years after birth than many experts once predicted, contradicting the notion that as a rule, cocaine-exposed infants would be born with devastating birth defects or miss major developmental milestones.
"I think the early information we had was that these children might be irreversibly damaged - that they would potentially have lots of problems in school, that they might have lots of behavior problems, that they might have problems thinking and learning," said UF neonatologist Marylou Behnke, M.D.
Instead, UF researchers write in the April online issue of the Journal of Pediatric Psychology, prenatal cocaine exposure is linked to smaller head circumference at birth and to less optimal home environments, which in turn have direct yet mild effects on developmental outcome at 3 years of age. Those effects persist at ages 5 and 7, once more demands are placed on the children during the formal school years, according to related findings the researchers presented at the recent annual meeting of the Society for Research in Child Development.
"We have found that at age 3, the more cocaine the child was exposed to, the smaller the head circumference at birth, and the smaller the head circumference at birth, the worse the developmental or cognitive outcomes," said Behnke, adding that head circumference at birth is an important measure because generally the head grows as brain size increases. "So cocaine is not directly affecting outcome, but it affects this intermediary measure that we're looking at that then goes on to affect outcome. We think that head circumference may be some sort of a marker for what is going on in the prenatal environment, that it's a proxy marker for other things."
Each year, about 45,000 infants who were exposed to cocaine in the womb are born, according to the National Institute on Drug Abuse. When the dangers of prenatal cocaine exposure first grabbed headlines in the mid-1980s, no studies had followed children beyond infancy. UF researchers began studying crack and cocaine users and their offspring about 13 years ago, launching a study funded by the National Institute on Drug Abuse that assesses physical and developmental outcomes among 300 children from birth on. Half the study participants were exposed to cocaine in utero, half were not; all were from rural areas of north Central Florida.
Average daily cocaine use among the 154 mothers who used drugs throughout pregnancy was $32.70, the cost equivalent of approximately three rocks of crack cocaine. Of that group, one quarter were considered "heavy users."
"We have found in our developmental studies of our newborns that there were some subtle differences between the groups, not the kind of things that moms and dads would notice particularly, not the kinds of things that family members might suspect if they saw the baby," said Behnke, a professor of pediatrics at UF's College of Medicine. "As the children have started to get older, we have begun to see a few more subtle effects, so by the time they were at six months, we could see some effect of cocaine on their developmental processes, but again, we're not talking about dramatic effects. And as they moved on to age 3, we began to see even more effects."
Cocaine-exposed children were assessed at age 3 in part by using the standardized assessment known as the Bayley Scales of Infant Development, which assesses a child's ability to perform age-appropriate functions such as following simple directions and completing puzzles and other problem-solving tasks. At 5 and 7, more extensive neuropsychological and intelligence testing was done.
"Some kids just have trouble getting going, getting started and once they get going they do a little better," said co-researcher Fonda Davis Eyler, a UF professor of pediatrics. "Others have trouble maintaining their attention and they respond to other cues and not what they're supposed to be targeting on and doing, or they only have simple strategies, not more complex ones."
The quality of the home environment was even more likely than smaller head size to influence outcome, Eyler said. UF researchers have analyzed measures of depression and self-esteem among caregivers and studied their views on parenting and child development. Children living in nurturing environments with supportive, competent caregivers scored higher on developmental measures, even when they had been exposed to cocaine before birth.
The children participating in the study are now entering the pre-teen years. As their academic responsibilities and social pressures increase, other, more serious effects may surface, Eyler said. Meanwhile, researchers are increasingly able to refine the tests they use to more precisely assess the children's progress, homing in on the areas of the brain more involved with planning and thinking strategically - the regions that cocaine, in theory, would most likely affect.
In this next arm of the study, all will undergo intelligence and achievement tests, including assessments of language ability, attention, problem-solving and abstract thinking, Eyler said. Researchers also will ask the youngsters about their attitudes, behavior, family relationships and friendships. In addition, they will assess the children's home environment and interview their caregivers and schoolteachers.
Deborah A. Frank, M.D., a professor of pediatrics at Boston University School of Medicine, said the UF team's work will "do much to dispel the inaccurate and hysterical predictions that inaccurately stigmatize children with intrauterine cocaine exposure."
"This is an important contribution to the field, since it thoughtfully addresses both biologic and social risk factors, viewing intrauterine cocaine exposure as only one of many possible influences on children," Frank said. "The importance of positive environmental characteristics in promoting toddler development, regardless of intrauterine cocaine exposure, is a crucial finding of this work that can guide evidence-based interventions for families.
"Although these findings are reassuring, long-term follow-up of this sample will be important, since intrauterine exposures such as tobacco and marijuana have been shown to have 'sleeper' effects on development that do not emerge until adolescence," she added.
UF study finds some people with oral pain wait too long before seeking help
GAINESVILLE, Fla. - Rural residents are nearly twice as likely as their urban counterparts to postpone timely trips to the dentist, seeking help only after they develop a problem and oral pain is severe, University of Florida researchers report.
The delay results in widespread dissatisfaction with treatment and less than optimal outcomes.
"What we found is there is a group of people who wait until their condition is of sufficient painful intensity and duration before deciding that it's bad enough to pick up the phone and call the dentist," said study investigator Joseph Riley, Ph.D., an assistant professor of public health services and research at UF's College of Dentistry. "There is evidence that these people assume this problem-oriented approach to oral health because of low access to care, whether that be due to an inability to pay or the lack of dentists practicing in rural areas," Riley added.
UF researchers, writing in the April issue of Public Health Reports, noted similar trends among blacks and women, though men with painful symptoms were the group most likely to entirely avoid dental visits, possibly attempting to self-medicate their pain at home to avoid going to the dentist.
Over a four-year period, the researchers studied patterns in access to dental care among 703 randomly selected people aged 45 years and older living in rural or urban counties in North Florida.
Researchers interviewed each participant and conducted an oral examination at the beginning of the study. They then conducted follow-up telephone interviews at six-month intervals to track financial status, symptoms of oral pain, and usage of dental services and treatment. Study participants were also interviewed in person and underwent additional oral examinations two and four years into the study.
Study investigators found rural residents and people who take a problem-oriented rather than preventive approach to oral health care were more likely to need emergency dental care for oral pain. People who live in rural areas and take a problem-oriented approach of opting to wait until oral discomfort worsened were at the highest risk of anyone for needing pain-related emergency treatment.
Over the course of the study, 23 percent of the participants experienced at least one emergency dental visit because of painful symptoms due to afflictions such as toothaches and abscesses. Sixty-seven percent of those who reported an emergency dental visit due to pain rated their discomfort severe. Overall, men were 20 percent less likely to seek and receive dental care at all, even when suffering from severe oral pain.
Only 56 percent of patients who visited the dentist for emergency treatment of painful oral conditions described themselves as "very satisfied" with the outcome of their treatment, versus 79 percent of those who sought urgent care but were pain-free at the time.
"What we found is that patients who had urgent dental visits because of pain were less likely to be satisfied by the time it took to be seen, the dental treatment they received and by the actual outcome of the visit," said Riley.
Riley said there is nothing unique about the dental choices people in rural North Florida make compared with residents living elsewhere. The UF study findings are consistent with data gathered by the National Center for Health Statistics, wherein minority and poor populations carry the burden of oral health problems, he said.
"The recent Surgeon General's report on oral health underscores the public health impact of oral health problems in the United States," said study co-investigator Gregg Gilbert, D.D.S., M.B.A., F.A.A.H.D., a professor and chairman of diagnostic sciences at the University of Alabama at Birmingham School of Dentistry. "Unfortunately, in the oral health arena, those most in need of care are the least likely to get it and a significant amount of suffering and embarrassment is part of everyday life for certain segments of our population."
The U.S. Surgeon General's landmark 2000 report on the country's oral health outlines substantial access to care barriers, such as ability to pay and a shortage of dentists in certain areas, and notes 11 percent of the nation's rural population has never visited a dentist. The report also calls the oral cavity the "mirror of health and disease." More than 90 percent of systemic diseases - such as diabetes, leukemia, cardiovascular disease and anemia - have oral manifestations, and people who have neglected their oral health are more likely to also have other medical problems.
Riley said he believes that access to care is not the only factor at play in determining why people with oral pain delay seeking dental treatment.
"Dentistry is really about social and psychological factors; it's perspective, and the preventive versus problem-oriented approach to dental care is an attitudinal belief," he said. "Therefore, it's something that can be changed."