Cocaine during pregnancy may slow child's growth

By Amy Norton

NEW YORK (Reuters Health) - Prenatal exposure to cocaine may have a lasting effect on a child's growth, new findings suggest.

In a study of 224 children followed from birth to age 10, researchers found that those whose mothers had used cocaine during the first trimester tended to grow at a slower rate than their peers.

On average, these children were smaller in terms of height, weight and head circumference by the age of 10, the study authors report in the journal Pediatrics.

Past research has tied prenatal cocaine exposure to a number of developmental delays and behavioral problems in childhood. Some studies, though not all, have also found that exposure to the drug may slow infants' growth -- and the long-term effects have not been clear.

For the current study, Dr. Gale A. Richardson and colleagues at the University of Pittsburgh School of Medicine recruited women attending a prenatal clinic. They interviewed the women about any drug, alcohol and tobacco use before their pregnancy and during the first trimester.

All women who reported any cocaine use during the first trimester were enrolled in the study, as was a comparison group that reported no cocaine use. Over the next decade, their children's growth was monitored with measurements taken at ages 1, 3, 7 and 10 years.

In general, Richardson's team found, children who'd been exposed to cocaine in the womb were smaller at ages 7 and 10.

Because the researchers were able to weigh other factors - like smoking, other drug use and mothers' height -- the results suggest that early cocaine exposure, itself, is responsible for the slowed long-term growth.

"It's an indicator that this drug has had a teratogenic effect," Richardson explained in an interview. Teratogenic effects refer to alterations in normal fetal development.

With any one cocaine-exposed child, there may be no obvious or severe growth delay, Richardson noted. However, the overall difference between the two groups of children in this study was significant.

Poorer growth can signify developmental problems. Head circumference, Richardson explained, is related to brain size, and can serve as an indirect indicator of developmental delay.

Some past studies have found that children exposed to cocaine in the womb tend to show deficits in certain aspects of mental function, like language skills and attention span.

Richardson said she and her colleagues are continuing to follow their study group to see whether the growth effects of prenatal cocaine exposure persist into adolescence.

SOURCE: Pediatrics, October 2007.