Pregnant women who quit smoking before the 15th week reduce risk of premature birth and small babies..

March 29, 2009 - In women who stopped smoking before 15 weeks’ gestation, rates of spontaneous preterm birth and small for gestational age infants did not differ from those in non-smokers, indicating that these severe adverse effects of smoking may be reversible if smoking is stopped early in pregnancy.

It's known that smoking during pregnancy increases the risk of miscarriage, ectopic pregnancy, premature birth, small babies, stillbirth and neonatal death, but no study until now has determined whether stopping smoking in early pregnancy reduces the risks of small babies and premature births, the study authors said.

"Pregnant women who smoke should be encouraged and assisted to become smoke-free early in pregnancy," said lead researcher Dr. Lesley McCowan, an associate professor of obstetrics and gynecology at the University of Auckland in New Zealand.

The study also found that women who stopped smoking WERE NOT more stressed than women who continued to smoke, McCowan noted.

"Health professionals who care for pregnant women need to ask about smoking, advise about the importance of stopping, and, where possible, refer for extra support early in pregnancy to assist women to become smoke-free," she advised.

PAPER: Spontaneous preterm birth and small for gestational age infants in women who stop smoking early in pregnancy: prospective cohort study,
Lesley M E McCowan, Gustaaf A Dekker, Eliza Chan, Alistair Stewart, Lucy C Chappell, Misty Hunter, Rona Moss-Morris, Robyn A North, BMJ 2009;338:b1081, ABSTRACT..

Dr. Richard Frieder, an associate clinical professor of obstetrics and gynecology at the University of California, Los Angeles David Geffen School of Medicine, said the study authors didn't explain whether this difference in low birth weight and gestational age at delivery actually translates into a measurable difference in newborn health.

"We assume this to be true, but there was only about a half pound difference in birth weight and six days difference in gestational age. These numbers are not very impressive that one would think a big difference in neonatal health would be achieved. Still, we should assume that a half pound and six days more of gestation is better and that we should strive to help women stop smoking," he said.

There are other big issues at play when it comes to babies, women and cigarette smoke, Frieder added. "Babies that live in 'smoking homes' have a much higher risk of respiratory ailments, such as asthma and pneumonia and SIDS. In addition, women are more susceptible to the cancer-causing effects of cigarette smoke than men. The tobacco industry specifically targets women, despite this well-known fact," he said.

Reference: Newly Pregnant Smokers Have a 15-Week Window to Quit by Steven Reinberg, Health Day, 3/27/2009.