It's also still a mystery as to why rates for black children are disproportionately higher for sudden infant death syndrome, or SIDS, than white babies. SIDS is the name for any unexplained sudden death in an infant less than 1 year old.
SIDS is the leading cause of death for children between 1 and 12 months and the third most common cause of infant mortality in general in the United States.
Public health authorities have issued recommendations about how babies should sleep to reduce the risk of SIDS. A national campaign called Safe to Sleep (formerly known as Back to Sleep) encourages parents to keep their babies sleeping on their backs, on a firm surface, and in a room of comfortable temperature.
Thanks in part to this campaign, SIDS deaths have declined by more than half since 1994. But the rates remain significantly higher for some demographic groups, including blacks. Deaths from SIDS in 2008 nationally were 55.4 per 100,000 live births in 2008, according to the National SUID/SIDS Resource Center, and for whites it was similar at 54.6. For blacks, however, it was 106.7.
Anitra Cooper of Jackson, Mississippi, had a son, Alex, who died suddenly at 3 months and 1 day old. It might have been because of sleeping on his stomach, but there's no way to know for sure.
"I was still breast-feeding him at the time," Cooper said. "I was doing everything that I could possibly do."
Cooper, who is black, did not know the extent of the country's racial divide in infant mortality until CNN told her how much more common infant deaths are among black children than white children.
She speculated that one factor may be that some women may leave their doctor's office without getting the information they need.
"A lot of people go to the doctor and don't make the doctor talk in layman's terms," Cooper said. "They're unaware of what they need to do for their children."
In the meantime, researchers are searching for evidence-based recommendations so that pregnant mothers can prevent preterm births and therefore reduce the risk of infant mortality. Currently, says Lackritz, there aren't any known interventions (beyond staying in good health and not smoking, drinking or using drugs) that would have a far-reaching impact on the entire population.
The hormone progesterone is used in an intramuscular injection, called 17 alpha-hydroxyprogesterone caproate, which may reduce risk in women who have given birth prematurely before.
"If we can increase access to that injectable medication, that can decrease preterm birth," said Currier, the Mississippi health officer.
Dykes received this injection with her next two children, whom she nearly carried nearly to full term although she had to have planned Caesarean sections with them.
Other methods for preventing preterm births have not proved useful scientifically. The American College of Obstetricians and Gynecologists says bed rest, hydration and pelvic rest do not appear to improve the rate of preterm birth and should not be routinely recommended.
Mississippi's infant mortality rate, although still the highest in the country, is slightly lower than it has ever been for the state, Currier said. The dip isn't statistically significant, but "at least we're going in the right direction," she said.
Cooper and Dykes both said they did everything right before giving birth to infants who died. They got all the prenatal care and education they needed. Neither woman was a teenager during pregnancy. They both work, and so do their husbands. They both have health insurance.
So the search for answers about infant mortality trends continues. The Dykes family tries to raise awareness for the cause through the March of Dimes, participating in the March of Dimes Walk to raise money in Jesse's memory.
Cooper now volunteers with the Mississippi SIDS Alliance to spread awareness. Such organizations exist, she says, not only for educational outreach, but "so that we can be strong and move on, and go through the proper stages of grief."
Both women are also strong in their faith.