That's the finding of a new national survey in the May-June issue of Nicotine & Tobacco Research.
The survey of 793 doctors covered 5,622 office visits by pregnant women. It found doctors identified the women's smoking status at 81 percent of the office visits but provided counseling to quit smoking only 23 percent of the time.
"Although physicians frequently identified the smoking status of pregnant women, they did not often counsel smokers about quitting," study author Dr. Susan Moran, of Harvard Medical School and the Tobacco Research and Treatment Center at Massachusetts General Hospital, says in a news release.
Smoking while pregnant can result in pregnancy complications, low baby birth weight and an increased risk of birth defects.
The survey found doctors identified the smoking status of white women more often than other women. But once pregnant smokers were identified, they received the same rate of counseling regardless of race.
Doctors in rural areas and southern states were less likely to counsel pregnant smokers. The survey also found doctors were more likely to determine whether or not a pregnant woman smoked on a return office visit than on a first visit.
The authors suggest that may be because doctors may want to avoid a confrontation with a patient during initial attempts to establish a rapport.
But determining a patient's smoking status at an early stage is important to begin prompt counseling to quite smoking. That's especially important with pregnant women because smoking during pregnancy often indicates alcohol and drug use as well, the authors note.
Here's where you can learn more about smoking and pregnancy.