In fact, more than 75 percent of the babies studied had no major problems, the same as a group of babies who were not exposed to cocaine in utero.
Earlier studies have attributed a variety of structural defects to prenatal cocaine exposure, including anomalies of the skull, heart, skeleton, gastrointestinal system and genito-urinary tract. But a series of new findings by UF researchers are serving to dispel much of the alarm generated by earlier reports of devastating effects of prenatal cocaine exposure.
"We are trying to put into perspective what the effects of prenatal cocaine exposure really are, and that's been hard to do," said Dr. Marylou Behnke, an associate professor of pediatrics at UF's College of Medicine. Behnke is scheduled to report the findings in New Orleans Monday (5/4) at the joint annual meeting of the American Pediatric Society and the Society for Pediatric Research.
"Earlier reports indicated prenatal exposure to cocaine resulted in terrible things, both in terms of anomalies and serious obstetrical complications. It appears that whatever effects such exposure has are far more subtle," Behnke said.
The research is part of a long-range study of crack and cocaine users and their offspring, designed to assess the physical and developmental effects of prenatal cocaine exposure.
Each year, about 45,000 infants exposed to cocaine in the womb are born, according to the National Institute on Drug Abuse.
More than 300 women ages 18 to 43 from rural areas of North Central Florida were enrolled in the two-year substudy after being matched for race, the number of children they had given birth to previously, prenatal risk and socioeconomic status. Physicians determined drug use through in-depth patient histories obtained after each trimester and urine screening for drug metabolites when participants entered the study and when they delivered.
Average daily cocaine use among the 154 women who used drugs was $32.70 throughout pregnancy, the equivalent of approximately three rocks of crack cocaine. Of that group, 30 women used an average of $10 a day throughout pregnancy.
Using a modified checklist of 50 major anomalies, researchers who were not told about the mothers' histories examined the babies within the first four days of life and assessed them accordingly.
Of the 301 babies who were alive at birth, 231 were included in the study analyses (112 who were exposed to cocaine and 119 who were not). The study excluded infants born before 37 weeks' gestation, who were too sick to be examined in-depth by four days, or who were missed because of scheduling errors.
The average number of anomalies per child did not differ by group, and no infant had more than three. The most common problem was a systolic heart murmur, present in 28 infants (11 percent of babies exposed to cocaine; 13 percent of those were not).
Meanwhile, UF researchers, writing in the February issue of the journal Pediatrics, caution "an even greater concern may be the potentially devastating effect of a self-fulfilling prophecy on a child who has been so negatively labeled. As researchers, we owe the public the truth, which would afford these children the benefit of hope and individualized care in lieu of negative labels of certain poor prognosis."
Behnke conceded the long-term future of these children remains uncertain.
"It may be that whatever subtle effects cocaine exposure has are related to future problems and may have profound impacts later on as these kids get to school age," she said.
Dr. Deborah Frank, an associate professor of pediatrics at the Boston University School of Medicine, said the UF research is important.
"Its methodology is sound and it confirms that cocaine is not a major cause of structural birth defects," Frank said. "There is still the need for long-term follow-up to see if there are subtle, long-term developmental outcomes." Behnke collaborated with Fonda Davis Eyler, an associate professor of pediatrics and neonatology; biostatistician Cynthia Wilson Garvan; project director Kathleen Wobie; and Michael Conlon, assistant vice president for health affairs for academic information systems and support.
(For more information contact Jennifer Donovan, Office of Media Relations, University of Maryland 504/670-8502, 504/670-8503 or 504/690-8508 or contact Health Science Center Office of Public Information 352/392-2621.)