Another Reason Not to Smoke While Pregnant: Birth Defects

Mar. 23 -- FRIDAY, Aug. 17 (HealthDay News) -- One of the first things every new parent does is count the baby's fingers and toes. But, women who smoke during pregnancy may be in for an unhappy surprise, because smoking increases the odds that a baby will be born with finger or toe deformities.

Just a half a pack a day increased the risk of having a baby with extra, missing or webbed fingers or toes by nearly 30 percent, according to a study in a recent issue of the journal Plastic and Reconstructive Surgery.

"One of the things that smoking does is interfere with oxygen delivery to cells at very key moments in development," explained Dr. Manuel Alvarez, chairman of the department of obstetrics and gynecology at Hackensack University Medical Center, in New Jersey. "If cells are deprived of oxygen, they don't proliferate as they should. If cells don't proliferate, you can have limb deformities."

About one out of every nine expectant mothers smokes, according to the March of Dimes. If no pregnant woman smoked, the rate of stillbirths would drop by 11 percent, and newborn deaths would decrease by about 5 percent, according to the March of Dimes. Smoking also increases the risk of preterm birth, a low birth-weight baby and cerebral palsy in the baby.

Limb defects aren't uncommon. About one in 600 babies is born with an extra finger or toe -- a condition known as polydactyly. A baby born with webbed toes or fingers -- syndactyly -- occurs in about one in every 2,000 to 2,500 births. Missing toes or fingers is known as adactyly. Webbed fingers or toes are more common in white babies, while excess digits are more common in black babies. Most of the time, these deformities occur in babies with no family history of such birth defects, which led researchers to suspect environmental causes.

After sifting through almost 7 million birth records from 2001 to 2002, researchers from the University of Pennsylvania found almost 5,200 babies born to women who smoked who also had deformed fingers or toes. None of the women who smoked had other medical conditions, such as high blood pressure or diabetes.