The emerging science suggests that decades-old "quit for your baby" messages are too simplistic an approach for many women - and that perhaps prenatal checkups should include screening pregnant smokers for mental health disorders that themselves require care.
"These ladies all know, I promise you, about the health risks. That's not what it is," says Dr. Jan Blalock of the University of Texas M.D Anderson Cancer Center, which has begun a first-of-a-kind study, Project Baby Steps, to test whether non-drug depression therapy helps pregnant smokers quit.
"We should at least understand more about why these ladies don't quit. We should be looking more carefully instead of just saying, 'Whoop, got this group of hard-core smokers."'
Nearly 45 million Americans, or one in five adults, smoke. Quitting takes on average three to five attempts, and scientists know it's harder if the smoker has depression or anxiety disorders. In fact, one prescription anti-smoking pill is actually the old antidepressant Wellbutrin sold under a different name, Zyban.
Certainly learning how dangerous smoking is to their developing baby can prompt women to try to quit. It increases the risk of miscarriage, premature birth, low birthweight, death from SIDS, and learning and behaviour disorders.
But only recently have researchers begun to delve into why, despite the enormous stigma, so many pregnant smokers don't quit. The U.S. government estimates about 12 per cent of pregnant women smoke.
Dr. Renee Goodwin, a Columbia University epidemiologist, tracked more than 1,500 pregnant women who took part in a larger study of Americans' health. A surprising 22 per cent smoked at some point during pregnancy, and about 12 per cent were classified as nicotine-dependent.
Pregnant smokers were typically poor, less educated and had less access to health care.
But strikingly, 30 per cent of the smokers had a mental health disorder, as did more than half who were nicotine-addicted - and the vast majority suffered depression. The smokers were about three times as likely to have a disorder as pregnant nonsmokers, Goodwin recently reported in the journal Obstetrics and Gynecology.
Smaller studies also have linked depression to smoking during pregnancy.
Nicotine and other chemicals in cigarette smoke can act in the brain like weak antidepressants, says Dr. Nora Volkow, director of the National Institute on Drug Abuse.
"They are not just smoking to get the habit-forming aspects," Volkow explains. "On top of that, they are seeking the therapeutic effect. It comes at a very, very high cost."
It can be hard for the depressed to realize when they need help. And chances of relapse increase when would-be quitters feel worsening sadness, lethargy or other depression symptoms.
That makes the smoking more "a disease instead of a choice," Volkow says. "Society's responsibility is to provide a treatment. Because here you have two individuals that will be affected."
But how to treat pregnant smokers?
While many smokers turn to medication to ease quitting pangs, doctors hesitate to prescribe even nicotine patches during pregnancy. Studies so far haven't proven the patches' role in pregnancy, and some suggest pregnant women metabolize nicotine faster and thus need higher doses, raising fetal safety questions. A major study is beginning in Britain to try to settle those questions.
What about alleviating depression to help them quit?
Antidepressants haven't been studied specifically in pregnant smokers. Generally, those drugs are reserved for severe symptoms during pregnancy, although recent studies suggest the risk of birth defects is low.
Enter Texas' Project Baby Steps. More than 250 pregnant smokers, and counting, are testing whether a form of cognitive therapy for depression helps them kick the habit better than anti-smoking counselling alone.
The psychological therapy is intense, teaching women to problem-solve so they can improve dysfunctional relationships that can fuel both the depression and the smoking, Blalock explains.
This is a high-risk group of poor, inner-city women. Almost half are currently suffering major depression, and Blalock says many also have a history of abuse or other trauma. But they volunteered for the study because they want to quit smoking.
It's not clear yet if depression plays a role for pregnant smokers in general, or is an added risk mostly for the poor, Blalock stresses.
Still, NIDA's Volkow says it's crucial to develop ways to help this uniquely vulnerable group.
"There's a lot of social disdain" for pregnant smokers, adds Columbia's Goodwin. "There aren't a lot of treatment programs. There's just advice ... not to smoke, but that's not going to do the job."
