In a new study on mothers who smoke while pregnant, ultrasound images show the fetuses grimacing and covering their faces, suggesting a direct reaction to nicotine, according to ABC News.
A small pilot study of 20 pregnant women -- four of them smoking during pregnancy -- were given ultrasound scans to observe the fetal activities at 24, 28, 32 and 36 weeks.
The study, published earlier this week in Acta Paediatrica, found that fetuses of smoking moms touch their face and mouth much more than fetuses of nonsmoking mothers. While smoking has long been known to cause complications in pregnancy, the study aims to show how the unborn baby of a smoking mother reacts differently.
The research team, led by Dr. Nadja Reissland of Durham University in the United Kingdom, investigated the minute mouth and hand movements of the fetuses in both the smoking and nonsmoking mothers using high-definition, 4-D ultrasounds.
Fetuses of the smoking mothers had a 58 percent increase of mouth movement and a 69 percent increase in self-touch, where the fetuses touched their face or head, compared to the unborn babies of women who didn't smoke.
"Fetal facial movement patterns differ significantly between fetuses of mothers who smoked compared to those of mothers who didn't smoke," said Reissland. "These results point to the fact that nicotine exposure per se has an effect on fetal development over and above the effects of stress and depression."
Reissland said the extra-movements made by the fetuses of smoking pregnancies could indicate that nicotine or other toxins from the smoke are having an effect on a fetus' development. Traditionally, the fetus' movement starts to lessen as they develop to full-term pregnancy.
"The brain...matures indicates certain movements for the fetus that the fetus can make, it's a proxy for brain development," said Reissland. "As they grow older, they integrate the movement [and] they make fewer but more complex movements."
ABC News reported that all infants in the study were born at a healthy weight and size with no obvious health issues.
Reissland hopes to follow up with the infants of smoking mothers to see whether they show any new signs of health effects or developmental delays related to their exposure to nicotine in the womb.
Doctors are hoping that the dramatic photos of babies exposed to nicotine could help discourage women from smoking during pregnancy.
According to the U.S. Centers of Disease Control and Prevention, 10 percent of women reported smoking during the last three months of pregnancy. Smoking during pregnancy has been connected a number of complications, including low birth weight, miscarriage, or premature birth.