SUBTLE POISON

No One Sees What Happens To Fetus Whose Mother Uses Drugs But The Effects
Are There

Wisconsin's cocaine mom law was put in place to protect a fetus from the
illegal drugs taken by its mother. That's why Rachael Lowe, a young
Waterford woman, was detained in late April when she sought help for an
OxyContin addiction. Her blood also showed traces of marijuana and the
sedative benzodiazepene.

While there are certainly effects on the fetus, experts say, they are not
what we once thought they would be, and in some cases they're just hard to
prove because of the other factors, such as poverty, that also effect how
children develop.

First is the danger of changing the fetus' body. That risk is usually
greatest before the third month of pregnancy, said Dr. David Sheftel,
director of neonatalogy for All Saints Healthcare System. "That's when the
organs are developing."

There are other issues related to drug use; "That has to do with effects
primarily on the brain."

Tangled Lives

Proof of drug effects is difficult to come by, he said, because so many
drug users use multiple drugs. Nor are the families of these children
necessarily stable, nor are they necessarily equipped to care for these
children, he said.

People try to link attention deficit hyperactivity disorder to maternal
drug use, too, Sheftel said, but ADHD is more likely to be genetically
based, and people who take drugs are more likely to develop the problem.

"It's very difficult to demonstrate a clearcut effect of cocaine and, in
her (Lowe's) case, opiates on the fetus," said Dr. Robert Risinger, a
psychiatrist and researcher at the Medical College of Wisconsin.

Some of the initial studies on the effects of drugs have been re-examined,
and it appears those supposed effects on children were also the result of
poverty and poor nutrition, "probably even more to do with those than
exposure to drugs," he said.

Some changes have shown up in children exposed to marijuana while in the
womb, said Cecilla Hillard, who holds a Ph.D. in pharmacology and is a
professor at the medical college. For many years a Canadian researcher
followed the children of several women who followed a healthy lifestyle
with plenty of natural foods, but who also used marijuana. "And the first
few years there were no differences."

When children reach the age of 6 or 7, a part of the brain called the
prefrontal cortex begins to operate, and children gain more self-awareness
and control over their impulses. (This region doesn't finish developing
until the early 20s.) The children of the marijuana users had trouble
controlling their anger.

"It fits a bunch of things that we probably already knew, which is the
effects of marijuana are probably very subtle," Hillard said.

Light One Up

The cocaine mom law is directed at the use of illegal drugs or the abuse of
controlled drugs, but legal drugs are dangerous, too.

"Tobacco is about as bad as you can get," Sheftel said. "Tobacco is
associated with a whole host of problems in the newborn, period."

Mothers who smoke experience a greater incidence of miscarriage, he said.
Their babies tend to be smaller.

"They tend not to grow very well, and that probably has to due with a lack
of oxygen and nutrients that get through the placenta to the baby."

These children have decreased brain growth and a greater risk for having
low blood sugar; and a lack of oxygen in the womb may cause their bodies to
compensate by overproducing red blood cells, which can damage the brain.
Plus, Sheftel said, tobacco is a suspected teratogen, which is a chemical
that can interfere with the operation of genes and cause malformation of
the fetus.

There is evidence that adolescence is a key time in determining a person's
propensity for later addiction, Risinger said. If a person has 10
cigarettes before the age of 16, there's a very high likelihood that person
will become addicted to smoking, Risinger said. "So that's what - half a
pack. And that's scary. As a father, that is scary."

Deep In The Brain

In the medical college's new imaging center, scientists have a pair of MRI
scanners several times more powerful than the typical medical diagnostic
instruments. With these - paid for in part by a grant from the Office of
National Drug Control Policy - researchers can get detailed images of what
happens when drugs invade a body.

"Clearly they hijack the natural rewards system," Risinger said.

Cocaine, for example, affects the movement of dopamine, one of the
chemicals that carry signals among the nerve cells in the brain. His lab
has looked at the effects of nicotine, cocaine and marijuana, Risinger
said, and all three activate the same parts of the brain.

One is an area called the nucleus accumbens, which is intimately involved
in both emotion and motivation. "People have demonstrated this part of the
brain is active when you gamble."

Also involved is the ventral tegument in the middle of the brain. It's part
of the reward circuit.

Another area affected is the hippocampus, which processes memories. For
addicts, the ring of a cell phone may trigger a craving because of strong
memories of drug use, Risinger said. One of the treatments used for
addicts, he added, is to try to replace memories of drug use with memories
of the unpleasant consequences - jail, job loss, and divorce, for example.

This is how powerful the hijacked reward system can be. Volunteer addicts
in the MRI scanner at the college were given low doses of narcotics and
then shown two videos. One showed drug use; the other was an erotic film.
People who weren't drug users were aroused by the erotic video. Addicts
were excited much more by the drug video.

"They'd rather have cocaine than sex," Risinger said.

High doses of the drugs they've studied turn off the nucleus accumbens, he
said, and one interpretation of this is that the normal reward system is
being shut down. People who are very addicted to cocaine show such
behavior, he said; they lose interest in eating, sleeping, and other normal
behaviors.

So cocaine inhibits people's ability to control impulses and make
decisions, Risinger said. Research subjects asked to stop themselves from
pressing a button while in the MRI scanner have to activate parts of the
brain affected by cocaine, and they can't stop.

"What's wrong with, 'Just say no'? They can't," Risinger said.

Deeper Still

Researchers in Texas have tied some addictive behavior to a gene called
Clock which is part of the system that controls animals' wake-sleep cycle
and also affects the ventral tegument reward circuit.

Hillard, the pharmacologist, has her sights set on another bit of cell anatomy.

Individual nerve cells in the brain don't touch each other directly.
They're separated by a tiny gap, called a synapse, and one cell releases
messenger chemicals which cross the gap and affect the next cell. These
messengers bind to special receptors that fit only molecules of a
particular shape.

Scientists have found that nerve cells make their own cannabinoids,
molecules like the active ingredient in marijuana (tetrahydrocannabinol, or
THC for short), and so cells have receptors for these.

If you remove this cannaboid receptor in animals, you eliminate cocaine and
heroin self-administration, she said, even though these drugs work by
different mechanisms.

"Cannabinoids increase the motivation for animals to do rewarding things,"
Hillard said. Turn on that cannabinoid receptor, and an animal will work
harder for any reward.

"The marijuana-induced munchies are not just a myth."

"And from what I just said, a really logical therapeutic agent to help
craving is an antagonist, or a blocker, for that cannabinoid receptor."

A French company already has such a drug that it intends to market as a way
to lower lipids in the blood, she said. Certainly in five to 10 years there
should be drugs available to intervene in the addiction process, Risinger said.

Hillard has other thoughts. She used to think the idea of marijuana as a
gateway drug - a drug that leads people to harder drugs such as cocaine -
was wrong, that social factors explained the link. "I think our animal data
suggests there is really a biological mechanism by which THC makes other
drugs more rewarding." Mostly that means stimulants such as cocaine and
marijuana, she said.

Cannabinoid receptors may also be present in the early stage of life, in
the fetus, she said, certainly there's evidence for this in animals. And
the receptors are for local signaling among cells. "Now you take a fetus
and you flood the brain, activating this receptor all at the same time in
these different brain regions.... Do you set into motion some genetic
program not meant to happen, or not meant to happen at that stage?"

Out In The World

When a child is born with an addiction, the process of helping that child,
or waiting for its liver to break down drugs, may take only a few days,
Sheftel said.

What takes more time, he said, is providing the social network and support
services that a family will need to properly care for that child.

"I see a lot of parents worry about medications or drugs they've taken
during the pregnancy," he said. Most medicines won't harm a fetus, but it's
important to speak with your doctor before taking anything, even an
over-the-counter drug.

You know now about the illegal drugs.

"The bottom line is using anything like that when you're pregnant is pretty
stupid," Hillard said. "But ... oftentimes people don't have the
self-control. The drugs themselves are addictive. That's the end of the story."

[Sidebar]

By The Numbers

4.3 - Percent of pregnant women ages 15 to 44 who had used illegal drugs in
the previous month, according to national surveys on drug use and health in
2002 and 2003.

4.1 - Percent of pregnant women who reported binge drinking.

8 - Percent of pregnant women ages 15 to 25 who used illegal drugs.

1.6 - Percent of pregnant women ages 26 to 44 who used illegal drugs.

18 - Percent of pregnant women who smoked.

Source: Substance Abuse and Mental Health Services Administration