Increased Risk Of Infant Mortality Lies With Obesity

pregnant woman posing outside leaning against a tree( — Obesity in pregnant women could increase the chance of the newborns to pass away in the first few weeks of his or hers life as research shows.

Given high infant mortality rates in the US as compared to other developed nations, the researchers say, if the results are confirmed, “obesity prevention should be explored as a measure to reduce infant mortality.”

Obese pregnant women are known to be at greater risk of fetal death, while there is also some evidence that death rates are higher among babies born to obese women, according to Dr. Aimin Chen of Creighton University School of Medicine in Omaha, Nebraska and colleagues.

To investigate the relationship in more detail, the researchers compared records for 4,265 babies who died in infancy and 7,293 surviving babies, using data from the 1988 National Maternal and Infant Health Survey.

Among the infants that died, 8.8 percent had obese mothers, compared to 5.9 percent of surviving infants. Babies born to obese women were at greater risk of death in their first year, and were also more likely to die in their first 28 days of life than infants born to normal-weight women.

While risk was increased for obese women no matter how much weight they gained, infant mortality was greatest among women who gained the most weight (0.45 kilogram or one pound and up each week), who were at nearly triple the risk of infant death. Risk was the second-highest for the obese women who gained the least weight (less than 0.15 kg or 0.33 pound a week), who were at 1.75 times greater risk of infant death.

A similar pattern was seen among overweight women, with those who gained the most weight and those who gained the least at highest risk.

A mother’s pre-pregnancy body mass index had the greatest influence on neonatal death. Deaths due to complications of pregnancy, labor and delivery as well as problems related to preterm birth or low birth weight were higher among infants born to all obese women, no matter how much weight a woman gained in pregnancy; however, increased risk of death due to respiratory problems, birth defects, and SIDS was only seen for the obese women in the highest weight-gain category.

One problem with their study, Chen and colleagues point out, is that the data is “old;” since 1988, the prevalence of obesity and the average amount of weight women gain during pregnancy has increased, while infant morality rates have dropped by around 20 percent. However, they note, deaths related to prematurity or low birth weight have not seen declined and may even be on the rise, “which may be related to increasing obesity and infertility treatment.”

SOURCE: Epidemiology, January 2009.


Prematurity Might Be Linked To Autism

pregnant african american woman( — A currently ongoing study might link autism to premature birth. The risk of autism has grown largely among preemies but more study is needed to be sure.

Last spring, researchers from Harvard Medical School and McGill University reported that one in four very low birth weight preemies showed early signs of autistic behavior when evaluated before age 2 in a study involving 91 children.

Now a much larger study shows that one in five toddlers born more than three months early showed early signs of autism spectrum disorder, regardless of their weight at birth.

Toddlers with established motor, visual, hearing, and mental handicaps were more likely to show early signs suggesting a high risk for autism, compared to children without these problems.

The studies don’t prove that extreme prematurity is directly linked to autism because the children who participated were too young to have a confirmed diagnosis, lead author Ken C. K. Kuban, MD, of the Boston University School of Medicine states.

“We should know more in a few years if we are able to follow these children,” he says.

Early Birth and Autism

The study included close to 1,000 children born at least three months early between 2002 and 2004, enrolled in a larger trial.

When the children reached age 2, they were tested for early signs of autism spectrum disorder using a widely used screening tool known as the Modified Checklist for Autism in Toddlers (M-CHAT).

When the M-CHAT is used to screen children during routine pediatric visits, about 5% test positive, Kuban says.

By comparison, 21% of the very premature children in the study had positive M-CHAT scores.

Slightly more than one in four (26%) had birth-related health issues, including cerebral palsy (11%), visual impairments (3%), and hearing impairments (2%).

The risk of having a positive M-CHAT increased 23-fold among children unable to sit or stand by themselves, eightfold among children with visual and hearing impairments, and 13-fold among children with severe mental impairment.

Nearly half of the children with cerebral palsy and two-thirds of the children with visual or hearing problems tested positive on the M-CHAT screen.

“Children who had these impairments were more likely to be M-CHAT positive, but that didn’t mean they were necessarily at higher risk for autism,” Kuban says. “The message to pediatricians is that they need to be cautious in interpreting the results of this screening test in children with these handicaps.”

Healthier Preemies Scored Better

When these children were excluded from the analysis, 10% of 2-year-olds without these disabilities still tested positive.

The study appears in the January issue of the Journal of Pediatrics.

“Children who had no motor, hearing, visual, or cognitive impairments still had double the risk of being M-CHAT positive,” Kuban says.

March of Dimes Medical Director Alan Fleischman, MD, stated that it is clear that very premature children — those born more than two months early, weighing 3 pounds or less — are at high risk for a wide range of birth-related developmental problems.

But it is not clear that those problems include autism spectrum disorder, he says.

“If a baby’s brain has been hurt by the consequences of extreme prematurity, it isn’t surprising that they display these symptoms, but I’m not sure it is helpful to label it autism,” he says. “Certainly, these babies need to be evaluated closely. That is an important message.”