• Posted January 30, 2023

Smoking in Pregnancy Greatly Raises Odds for SIDS in Newborns

Infants exposed to maternal smoking during pregnancy are more than five times more likely to die unexpectedly compared to babies of nonsmokers, a new study says.

"The message is simple. Smoking greatly elevates the risk of sudden unexpected infant death," said lead study author Barbara Ostfeld, program director of the SIDS Center of New Jersey and a professor of pediatrics at Rutgers Robert Wood Johnson Medical School in New Brunswick, N.J.

"Everyone who plans to get pregnant has a profoundly important reason to quit," Ostfeld said in a school news release.

Each year, about 3,400 sudden unexpected infant deaths (SUID) occur in the United States, according to the Centers for Disease Control and Prevention. These deaths occur in an infant's first year. They include those attributed to sudden infant death syndrome (SIDS), those with no immediately obvious cause, as well as those caused by accidental suffocation.

The Rutgers analysis studied SUID in infants born in the United States, including 3.3 million births to white women and more than 857,000 births to Black women.

Researchers used birth and death records maintained by the CDC for 2012 to 2013 for infants born between 24 and 42 weeks gestation. And they included SUID cases in which the infant died after hospital discharge and an autopsy was performed.

While a smaller percentage of Black than white mothers reported smoking, the risk of SUID rose with the duration of smoking for both races, increasing with every trimester of in-utero exposure, according to the study.

Researchers calculated a SUID rate of 0.34 per 1,000 live births for infants of white mothers who never smoked, and 2.33 for infants of steady smokers.

About 16% of white mothers of surviving infants smoked either during or before pregnancy, while about 50% of the white mothers of SUID victims smoked.

For Black women who never smoked, the SUID rate was 1.07 deaths per 1,000 live births. That rose to 3.80 for infants born to those who smoked throughout pregnancy.

About 10% of Black mothers of surviving infants smoked either during or before pregnancy compared to nearly 25% of mothers of babies who died of SUID.

Among smokers whose infants died of SUID, 78% of white smokers and 67% of Black smokers smoked throughout pregnancy.

"Given the strong connection between smoking and SUID, it was concerning that the majority of those in either racial group who had been smokers continued to smoke through the pregnancy," said study co-author Dr. Thomas Hegyi, medical director of the SIDS Center of New Jersey and professor of pediatrics at Rutgers Robert Wood Johnson Medical School.

"This finding underscores the difficulty smokers have with quitting and suggests that there is a national need for more effective approaches as well as better access to these services," Hegyi said in the release.

More information

The U.S. Centers for Disease Control and Prevention has more on SUID and SIDS.

SOURCE: Rutgers Robert Wood Johnson Medical School, news release, Jan. 27, 2023