THE EPIDEMIC THAT WASN'T

BALTIMORE -- One sister is 14; the other is 9. They are a vibrant
pair: the older girl is high-spirited but responsible, a solid
student and a devoted helper at home; her sister loves to read and
watch cooking shows, and she recently scored well above average on
citywide standardized tests.

There would be nothing remarkable about these two happy, normal girls
if it were not for their mother's history. Yvette H., now 38, admits
that she used cocaine (along with heroin and alcohol) while she was
pregnant with each girl. "A drug addict," she now says ruefully,
"isn't really concerned about the baby she's carrying."

When the use of crack cocaine became a nationwide epidemic in the
1980s and '90s, there were widespread fears that prenatal exposure to
the drug would produce a generation of severely damaged children.
Newspapers carried headlines like "Cocaine: A Vicious Assault on a
Child," "Crack's Toll Among Babies: A Joyless View" and "Studies:
Future Bleak for Crack Babies."

But now researchers are systematically following children who were
exposed to cocaine before birth, and their findings suggest that the
encouraging stories of Ms. H.'s daughters are anything but unusual.
So far, these scientists say, the long-term effects of such exposure
on children's brain development and behavior appear relatively small.

"Are there differences? Yes," said Barry M. Lester, a professor of
psychiatry at Brown University who directs the Maternal Lifestyle
Study, a large federally financed study of children exposed to
cocaine in the womb. "Are they reliable and persistent? Yes. Are they big? No."

Cocaine is undoubtedly bad for the fetus. But experts say its effects
are less severe than those of alcohol and are comparable to those of
tobacco -- two legal substances that are used much more often by
pregnant women, despite health warnings.

Surveys by the Department of Health and Human Services in 2006 and
2007 found that 5.2 percent of pregnant women reported using any
illicit drug, compared with 11.6 percent for alcohol and 16.4 percent
for tobacco.

"The argument is not that it's O.K. to use cocaine in pregnancy, any
more than it's O.K. to smoke cigarettes in pregnancy," said Dr.
Deborah A. Frank, a pediatrician at Boston University. "Neither drug
is good for anybody."

But cocaine use in pregnancy has been treated as a moral issue rather
than a health problem, Dr. Frank said. Pregnant women who use illegal
drugs commonly lose custody of their children, and during the 1990s
many were prosecuted and jailed.

Cocaine slows fetal growth, and exposed infants tend to be born
smaller than unexposed ones, with smaller heads. But as these
children grow, brain and body size catch up.

At a scientific conference in November, Dr. Lester presented an
analysis of a pool of studies of 14 groups of cocaine-exposed
children -- 4,419 in all, ranging in age from 4 to 13. The analysis
failed to show a statistically significant effect on I.Q. or language
development. In the largest of the studies, I.Q. scores of exposed
children averaged about 4 points lower at age 7 than those of
unexposed children.

In tests that measure specific brain functions, there is evidence
that cocaine-exposed children are more likely than others to have
difficulty with tasks that require visual attention and "executive
function" -- the brain's ability to set priorities and pay selective
attention, enabling the child to focus on the task at hand.

Cocaine exposure may also increase the frequency of defiant behavior
and poor conduct, according to Dr. Lester's analysis. There is also
some evidence that boys may be more vulnerable than girls to behavior problems.

But experts say these findings are quite subtle and hard to
generalize. "Just because it is statistically significant doesn't
mean that it is a huge public health impact," said Dr. Harolyn M.
Belcher, a neurodevelopmental pediatrician who is director of
research at the Kennedy Krieger Institute's Family Center in Baltimore.

And Michael Lewis, a professor of pediatrics and psychiatry at the
Robert Wood Johnson Medical School in New Brunswick, N.J., said that
in a doctor's office or a classroom, "you cannot tell" which children
were exposed to cocaine before birth.

He added that factors like poor parenting, poverty and stresses like
exposure to violence were far more likely to damage a child's
intellectual and emotional development -- and by the same token,
growing up in a stable household, with parents who do not abuse
alcohol or drugs, can do much to ease any harmful effects of prenatal
drug exposure.

Possession of crack cocaine, the form of the drug that was widely
sold in inner-city, predominantly black neighborhoods, has long been
punished with tougher sentences than possession of powdered cocaine,
although both forms are identically metabolized by the body and have
the same pharmacological effects.

Dr. Frank, the pediatrician in Boston, says cocaine-exposed children
are often teased or stigmatized if others are aware of their
exposure. If they develop physical symptoms or behavioral problems,
doctors or teachers are sometimes too quick to blame the drug
exposure and miss the real cause, like illness or abuse.

"Society's expectations of the children," she said, "and reaction to
the mothers are completely guided not by the toxicity, but by the
social meaning" of the drug.

Research on the health effects of illegal drugs, especially on unborn
children, is politically loaded. Researchers studying children
exposed to cocaine say they struggle to interpret their findings for
the public without exaggerating their significance -- or minimizing it, either.

Dr. Lester, the leader of the Maternal Lifestyle Study, noted that
the evidence for behavioral problems strengthened as the children in
his study and others approached adolescence. Researchers in the study
are collecting data on 14-year-olds, he said, adding: "Absolutely, we
need to continue to follow these kids. For the M.L.S., the main thing
we're interested in is whether or not prenatal cocaine exposure
predisposes you to early-onset drug use in adolescence" or other
mental health problems.

Researchers have long theorized that prenatal exposure to a drug may
make it more likely that the child will go on to use it. But so far,
such a link has been scientifically reported only in the case of
tobacco exposure.

Teasing out the effects of cocaine exposure is complicated by the
fact that like Yvette H., almost all of the women in the studies who
used cocaine while pregnant were also using other substances.

Moreover, most of the children in the studies are poor, and many have
other risk factors known to affect cognitive development and behavior
- -- inadequate health care, substandard schools, unstable family
situations and exposure to high levels of lead. Dr. Lester said his
group's study was large enough to take such factors into account.

Ms. H., who agreed to be interviewed only on the condition that her
last name and her children's first names not be used, said she
entered a drug and alcohol treatment program about six years ago,
after losing custody of her children.

Another daughter, born after Ms. H. recovered from drug and alcohol
abuse, is thriving now at 3. Her oldest, a 17-year-old boy, is the
only one with developmental problems: he is autistic. But Ms. H. said
she did not use cocaine, alcohol or other substances while pregnant with him.

After 15 months without using drugs or alcohol, Ms. H. regained
custody and moved into Dayspring House, a residential program in
Baltimore for women recovering from drug abuse, and their children.

There she received psychological counseling, parenting classes, job
training and coaching on how to manage her finances. Her youngest
attended Head Start, the older children went to local schools and
were assigned household chores, and the family learned how to talk
about their problems.

Now Ms. H. works at a local grocery, has paid off her debts, has her
own house and is actively involved in her children's schooling and
health care. She said regaining her children's trust took a long
time. "It's something you have to constantly keep working on," she said.

Dr. Belcher, who is president of Dayspring's board of directors, said
such programs offered evidence-based interventions for the children
of drug abusers that can help minimize the chances of harm from past
exposure to cocaine or other drugs.

"I think we can say this is an at-risk group," Dr. Belcher said. "But
they have great potential to do well if we can mobilize resources
around the family."