For the second year in a row, 43 infants died in Mobile County before reaching their first birthday, records show. Twelve of the deaths were sleep-related, compared to 16 in 2008. Sleep-related deaths include suffocation when babies are in a bed with a parent or sibling, as well as Sudden Infant Death Syndrome. Nationally, statistics indicate that sleep-related death rates have fallen significantly since experts began telling parents to let babies sleep only on their backs. Factors such as sharing beds and a lack of circulating air in a baby’s room have both been shown to contribute to such deaths. Instead of sharing a bed, an infant can simply sleep in the same room as the parents, but in a crib, said Tony Bondora, who investigates infant deaths for the local Health Department. Also, he said, parents must make sure that sitters know not to let babies sleep on their stomachs or sides, even if they are just napping. “We are seeing more and more caregivers that are not following the recommendation. The babysitter doesn’t get the message and suddenly you have a very dangerous situation,” said Bondora, who is also coordinator of the Alabama Baby Coalition. New research suggests a great risk of SIDS for infants who are put to sleep on their stomachs after typically sleeping on their backs. “It appears that some infants are predisposed to lower seratonin levels, and that may be related to SIDS deaths,” Bondora said. In Baldwin County in 2009, there were 19 infant deaths, with 16 recorded the previous year, records show. Statewide, there were 513 infant deaths in Alabama in 2009, which meant the state’s infant mortality rate — the number of babies who died during their first year per 1,000 live births — dropped from 9.5 a year earlier to 8.2, according to records. That 8.2 rate was the lowest since the state began keeping such records more than 100 years ago, but was still among the highest in the country. Some factors related to the statewide drop in deaths last year, health officials said, was that fewer women smoked and fewer teenagers gave birth.