Study: Sunny climates may reduce ADHD

A study indicates many risk factors for ADHD, and interestingly notes that sunny and warm climates may reduce the condition.

Attention-deficit/hyperactivity disorder, or ADHD, is the most common childhood psychiatric disorder. Scientists do not know what causes it, but genetics play a clear role. Other risk factors have also been identified, including premature birth, low birth weight, a mother's use of alcohol or tobacco during pregnancy, and environmental exposures to toxins like lead.

ADHD is characterized by an inability to focus, poor attention, hyperactivity, and impulsive behavior, and the normal process of brain maturation is delayed in children with ADHD. Many individuals with ADHD also report sleep-related difficulties and disorders. In fact, sleep disorder treatments and chronobiological interventions intended to restore normal circadian rhythms, including light exposure therapy, have been shown to improve ADHD symptoms.

Estimates suggest that the average worldwide prevalence of ADHD ranges from about 5 to 7%, but it also varies greatly by region. A simple visual comparison of data maps released by the U.S. Centers for Disease Control and Prevention and the U.S. Department of Energy that display ADHD prevalence rates by state and solar intensities (sunlight) across the country, respectively, reveals an interesting pattern indicative of an association. So does this mean that there could be an identifiable relationship between ADHD prevalence rates and the sunlight intensity levels of particular regions?

The accumulation of these points led Dr. Martijn Arns and his colleagues to systematically and scientifically investigate this question. They collected and analyzed multiple data-sets from the United States and 9 other countries. Reporting their findings in the current issue of Biological Psychiatry, they did find a relationship between solar intensity and ADHD prevalence.

Even after controlling for factors that are known to be associated with ADHD, both U.S. and non-U.S. regions with high sunlight intensity have a lower prevalence of ADHD, suggesting that high sunlight intensity may exert a 'protective' effect for ADHD.

To further validate their work, they also looked at this same relationship with autism and major depressive disorder diagnoses. They found that the findings were specific to ADHD, with no associations observed between the other two disorders.

"The reported association is intriguing, but it raises many questions that have no answers," commented Dr. John Krystal, Editor of Biological Psychiatry. "Do sunny climates reduce the severity or prevalence of ADHD and if so, how? Do people prone to develop ADHD tend to move away from sunny climates and if so, why?"

As with all scientific research, further work is necessary, including a prospective replication of these findings. It is also important to realize that this data reflects only an association -- not a causation -- between ADHD and solar intensity levels so worried parents should not start planning cross-country moves.

However, these findings do have significant implications, explains Dr. Arns. "From the public health perspective, manufacturers of tablets, smartphones and PCs could investigate the possibility of time-modulated color-adjustment of screens, to prevent unwanted exposure to blue light in the evening."

"These results could also point the way to prevention of a sub-group of ADHD, by increasing the exposure to natural light during the day in countries and states with low solar intensity. For example, skylight systems in classrooms and scheduling playtime in line with the biological clock could be explored further."

Read more here

Risk of autism linked to induced labor

This article discusses a study that claims women who have induced labor are more likely to have an autistic child.

A new study finds that pregnant women who have their labor started or sped up artificially are slightly more likely to have autistic children.

The increased autism risk likely stems from an underlying problem with the pregnancy, rather than any of the methods used to jump-start labor, says lead author Simon Gregory of the Duke Institute of Molecular Physiology.

It's possible that "infants destined to develop autism are less likely to send out the correct biochemical signals for normal progression of labor," says Tara Wenger, a pediatric genetics fellow at the Children's Hospital of Philadelphia, who wasn't involved in the new study, published in JAMA Pediatrics.

Pregnancy complications increase the risk of many developmental disorders, says Michael Rosanoff, associate director for public health research and scientific review at Autism Speaks, an advocacy group.

And a growing number of studies now link autism to a variety of things that can compromise the health of a pregnancy, says Rosanoff, who wasn't involved in the study, funded by the Environmental Protection Agency. Researchers are increasingly looking at prenatal risk factors for autism, because this period plays a key role in brain development. Science has ruled out vaccines as a cause of autism, he says.

But studies have found that children are at higher risk for autism if they are born early or very small; if they are in medical distress during delivery; if they have older mothers or fathers; or if they are born less than a year after an older sibling. Autism risk also goes up if a mother has diabetes or high blood pressure; is obese; is exposed to significant air pollution during pregnancy; had low levels of folic acid; takes medications such as an anti-seizure drug called valproic acid; or makes antibodies toxic to the fetal brain.

Gregory notes that his findings are still preliminary and that women shouldn't resist a doctor's recommendation about jump-starting labor out of fear of autism.

Inducing labor can often reduce the risk of stillbirth, such as when a pregnancy lasts more than a week or so beyond the usual 40 weeks, says co-author Chad Grotegut, a Duke maternal-fetal medicine specialist. Augmenting labor, which may be done when natural labor stalls, can reduce the risk of maternal or fetal infections or post-partum hemorrhage.

And while the link between autism and jump-starting labor is consistent with smaller, earlier studies, the research doesn't prove that labor induction or augmentation actually causes autism, Gregory says.

In the new study, researchers analyzed the records of 625,042 North Carolina births, which were linked to school records that noted any diagnosis of autism.

Those records didn't specify where children fell on the autism spectrum, the study says.

Doctors can induce or speed up labor in several ways, such as by applying a hormone gel to the cervix or giving women intravenous oxytocin, an artificial version of a natural hormone involved in labor, Gregory says.

Women whose labor was induced were 13% more likely to have an autistic child, compared to women whose labor wasn't induced. Women whose labor was sped up were 16% more likely to have a child later diagnosed with autism, the study found. Those whose labor was both induced and augmented were 27% more likely to have an autistic child.

In comparison, the risk of autism went up 23% when the mother had diabetes, and 25% when the fetus was in distress, the study says.

There was no increase in autism risk among women who had C-sections, Gregory says.

He says scientists should look more closely at labor induction with oxytocin. Oxytocin, sometimes called the "love hormone," plays a key role in social behavior and reasoning.

Gregory and other researchers are investigating oxytocin to treat some of the symptoms of autism.

About one in 88 American children have an autism diagnosis, according to the Centers for Disease Control and Prevention.

Rather than one disease, autism is now regarded as a collection of conditions with similar traits but different causes, Rosanoff says. People on the autism spectrum are extremely diverse. Some are non-verbal and profoundly disabled; others have successful careers, particularly in science and technology, describing themselves as different, rather than disabled.

"Autism is so heterogeneous," Rosanoff says. "We're never going to get to the one cause."

Read more here

Study claims poor sleep during pregnancy can cause birth complications

Not getting enough quality sleep during pregnancy can lead to birth complications such as low birth weight. It is important to treat sleep issues during pregnancy early.

Poor sleep quality and quantity during pregnancy can disrupt normal immune processes and lead to lower birth weights and other complications, finds a University of Pittsburgh School of Medicine study published today in the journalPsychosomatic Medicine. Women with depression also are more likely than non-depressed women to suffer from disturbed sleep and to experience immune system disruption and adverse pregnancy outcomes.

"Our results highlight the importance of identifying sleep problems in early pregnancy, especially in women experiencing depression, since sleep is a modifiable behavior," said Michele Okun, Ph.D., assistant professor of psychiatry at Pitt's School of Medicine and lead author of the report. "The earlier that sleep problems are identified, the sooner physicians can work with pregnant women to implement solutions."

Adequate and high-quality sleep, both in pregnant and non-pregnant women as well as men, is essential for a healthy immune system. Pregnancy often is associated with changes in sleep patterns, including shortened sleep, insomnia symptoms and poor sleep quality. These disturbances can exacerbate the body's inflammatory responses and cause an overproduction of cytokines, which act as signal molecules that communicate among immune cells.

"There is a dynamic relationship between sleep and immunity, and this study is the first to examine this relationship during pregnancy as opposed to postpartum," added Dr. Okun.

While cytokines are important for numerous pregnancy-related processes, excess cytokines can attack and destroy healthy cells and cause destruction of tissue in pregnant women, thereby inhibiting the ability to ward off disease. For expectant mothers, excess cytokines also can disrupt spinal arteries leading to the placenta, cause vascular disease, lead to depression and cause pre-term birth.

Previous studies conducted postpartum have shown higher inflammatory cytokine concentrations among women who experienced adverse pregnancy outcomes such as preeclampsia and pre-term birth. While infection accounts for half of these adverse outcomes, researchers discovered that behavioral processes such as disturbed sleep also may play a role, given the relationship between sleep disturbance and immune function.

Furthermore, higher concentrations of inflammatory cytokines also are found in depressed individuals.

The study is the first to evaluate all factors -- inflammatory cytokines, depression and insomnia -- and their possible combined effect on pregnant women. The study examined nearly 170 women, both depressed and not depressed, at 20 weeks of pregnancy and analyzed their sleep patterns and cytokine production levels over the course of 10 weeks (pregnancy-related physiological adaptations are in flux prior to 20 weeks).

The findings reveal:

• Women with depression and poor sleep are at greatest risk for adverse birth-related outcomes. Cytokine levels may be one biological pathway through which this is accomplished, particularly with regard to preterm birth.
• Any shift in immunity, such as poor sleep and/or depression, could set the stage for increased risk for adverse outcomes.
• At 20 weeks, depressed pregnant women have higher levels of inflammatory cytokines compared to non-depressed women.
• At 30 weeks of pregnancy, differences in cytokines among depressed and non-depressed women were negligible, likely because as pregnancy progresses, levels of cytokines normally increase.

Read more here

Study: In-Vitro fertilization related to slight risk of mental deficit

A new study claims that children born through in-vitro fertilization have a slightly higher risk of having a mental deficit, possibly due to a lower birth weight.

Despite some concerns, children born by in vitro fertilization do not seem to have an increased risk of autism, a large new study finds. They may, however, have a slightly higher-than-normal chance of being intellectually impaired.

The study, reported in the July 3 issue of the Journal of the American Medical Association, looked at more than 2.5 million infants born in Sweden between 1982 and 2007. It found that the nearly 31,000 children conceived via in vitro fertilization (IVF) did not have an increased risk of the developmental disorder autism.

They were, however, 18 percent more likely to have an intellectual disability (which used to be called mental retardation), defined as an IQ lower than 70 and limited abilities in schoolwork .

Experts stressed that the risk is quite low: The rate of intellectual disability among IVF kids was about 46 per 100,000 each year, versus about 40 per 100,000 among kids conceived naturally.

"The vast majority of children born after the different types of IVF treatment will be perfectly healthy," said lead researcher Sven Sandin, of the Karolinska Institute, in Stockholm, and King's College London, in England.

What's more, the risk seemed largely related to the fact that babies born via IVF are often multiples (such as twins or triplets), and, therefore, frequently born preterm or at a low weight. That in itself carries a higher-than-normal risk of intellectual disability.

Experts said the findings suggest that whenever possible, IVF should involve implanting only one embryo in the woman's uterus, rather than the traditional route of implanting at least two.

"From the results of this study, we think that the use of single-embryo transfer should be extended," Sandin said.

An infertility specialist not involved in the study agreed. "I think we should be encouraging more single-embryo transfers," said Dr. Marcelle Cedars, director of reproductive endocrinology at the University of California, San Francisco.

That is happening more often these days, said Cedars, who wrote an editorial published with the study. At her center, she said, more than half of IVF patients have a single embryo implanted -- although that is higher than the national norm.

There is still a chance, however, that certain IVF procedures carry a risk.

Sandin's team found that a specific IVF technique used for male infertility -- called intracytoplasmic sperm injection, or ICSI -- was related to an increased risk of intellectual disability, even among single babies.

Again, the actual rates of intellectual impairment were quite low, Sandin said. But the results suggest there could be something about the intracytoplasmic sperm injection, or fathers' infertility, that contributes to the risk.

"People have for some time been concerned about the ICSI procedure," Cedars said.

That is partly because intracytoplasmic sperm injection is invasive: A single sperm is injected directly into an egg, whereas in standard IVF, sperm fertilize the eggs in a lab dish. "[ICSI] also bypasses the natural selection of sperm" that happens during fertilization, Cedars said, in which sperm compete to penetrate the egg and the fittest one wins.

But an alternative explanation is that male infertility -- which may involve genetically abnormal sperm -- is raising the risk of intellectual disability, rather than some effect of intracytoplasmic sperm injection, Cedars said.

Sandin agreed, but said it's impossible to say for sure based on these findings.

The study corroborates past research that has found no excess risk of autism after IVF. But this is by far the largest and best designed study to look at the question, Cedars said.

"This gives us powerful evidence that there is no association with autism," she said. She added that expectant parents can also be reassured that the risk of intellectual disability linked to intracytoplasmic sperm injection is still very low, even if it's higher than the norm.

Although the study found an association between certain IVF procedures and a higher risk of intellectual disabilities in children, it did not establish a cause-and-effect relationship.

Cedars and Sandin both said more studies are needed to see how children fare after IVF, and to dig for reasons for the current findings on ICSI.

Between 1978 and 2012, about 5 million children worldwide were born via IVF, and the numbers will only increase, Cedars said. And in some countries -- including the United States -- intracytoplasmic sperm injection is being increasingly used in cases in which there is no clear problem with the man's fertility, because there is a perception that it's more efficient.

But that belief, Sandin's team said, is unproven.

Read more here

Babies with high birth weight at greater risk for autism

A large study of autism indicated that a larger birthweight can mean a child has a greater risk for developing autism.

The biggest study of fetal growth and autism to date has reported that babies whose growth is at either extreme in the womb, either very big or very small, are at greater risk of developing autism.

It is the first time that a clear link has been made between babies who grow to above average size at birth and risk of Autism Spectrum Disorder and follows from a study of more than 40,000 child health records in Sweden.

The research, led by The University of Manchester, also confirms earlier research which reported that premature and poorly grown, low weight babies appear more susceptible to the condition.

Autism affects how individuals interact with the world and with other people and there is no known cure. One child in 100 has the condition in the UK according to NHS figures. Researchers believe it has origins in both genetic and environmental causes. Professor Kathryn Abel, from the University's Centre for Women's Mental Health and Institute of Brain, Behaviour and Mental Health, led the research published in The American Journal of Psychiatry.

Professor Abel said: "The processes that leads to ASD probably begin during fetal life; signs of the disorder can occur as early as three years of age. Fetal growth is influenced by genetic and non-genetic factors. A detailed understanding of how fetal growth is controlled and the ways in which it is associated with ASD are therefore important if we are to advance the search for cures.

"To our knowledge, this is the first large prospective population-based study to describe the association between the degree of deviance in fetal growth from the normal average in a population of children and risk of ASD with and without intellectual disability.

"We have shown for the first time categorically that abnormal fetal growth in both directions increases risk of autism spectrum disorder." Researchers looked at data from the Stockholm Youth Cohort in Sweden, where early ultrasound dating provides detailed weights of the baby's progression in pregnancy. Infants and children then also take part in structured clinical assessments of their social, motor, language and cognitive abilities.

The cohort contained records of 589,114 children aged 0-17 in Sweden between 2001 and 2007. Certain child data was removed, including children too young to have a diagnosis for ASD, adopted children and non Swedish or Stockholm County residents, children not born in Sweden and twins.

From the remaining available data, researchers found 4,283 young people with autism and 36,588 who did not have the condition and who acted as the control.

The study found that bigger babies who were born weighing over 4.5kg (or 9lb 14) showed a higher incidence of autism, as did smaller infants who were born weighing less than 2.5kg (5.5lb).

A baby who had poor fetal growth would therefore have a 63% greater risk of developing autism compared to normally grown babies.

A baby who was large at birth would have a 60% greater risk. This effect was independent of whether or not the baby was born pre- or post-term.

Professor Abel added: "We think that this increase in risk associated with extreme abnormal growth of the fetus shows that something is going wrong during development, possibly with the function of the placenta.

"Anything which encourages abnormalities of development and growth is likely to also affect development of the baby's brain. Risk appeared particularly high in those babies where they were growing poorly and continued in utero until after 40 weeks. This may be because these infants were exposed the longest to unhealthy conditions within the mother's womb.

"We now need more research into fetal growth, how it is controlled by the placenta and how this affects how the brain develops. One of the key areas to research is maternal condition and healthy growth."

The study was also unique as it was big enough to be able to look at the differences between children who developed ASD with and those without intellectual disability as well as differences between children born pre and post-term (after 40 weeks).

Read more here

Study: Ultrasound shows risk of autism at birth

This study claims that an ultrasound within the first few days of life can show brain abnormalities that can indicate a risk of developing autism later in life.

Low-birth-weight babies with a particular brain abnormality are at greater risk for autism, according to a new study that could provide doctors a signpost for early detection of the still poorly understood disorder.

Led by Michigan State University, the study found that low-birth-weight newborns were seven times more likely to be diagnosed with autism later in life if an ultrasound taken just after birth showed they had enlarged ventricles, cavities in the brain that store spinal fluid. The results appear in the Journal of Pediatrics.

"For many years there's been a lot of controversy about whether vaccinations or environmental factors influence the development of autism, and there's always the question of at what age a child begins to develop the disorder," said lead author Tammy Movsas, clinical assistant professor of pediatrics at MSU and medical director of the Midland County Department of Public Health.

"What this study shows us is that an ultrasound scan within the first few days of life may already be able to detect brain abnormalities that indicate a higher risk of developing autism."

Movsas and colleagues reached that conclusion by analyzing data from a cohort of 1,105 low-birth-weight infants born in the mid-1980s. The babies had cranial ultrasounds just after birth so the researchers could look for relationships between brain abnormalities in infancy and health disorders that showed up later. Participants also were screened for autism when they were 16 years old, and a subset of them had a more rigorous test at 21, which turned up 14 positive diagnoses.

Ventricular enlargement is found more often in premature babies and may indicate loss of a type of brain tissue called white matter.

"This study suggests further research is needed to better understand what it is about loss of white matter that interferes with the neurological processes that determine autism," said co-author Nigel Paneth, an MSU epidemiologist who helped organize the cohort. "This is an important clue to the underlying brain issues in autism."

Prior studies have shown an increased rate of autism in low-birth-weight and premature babies, and earlier research by Movsas and Paneth found a modest increase in symptoms among autistic children born early or late.

The study was supported by a grant from the National Institutes of Health.

Read more here

Reduced Risk of Preterm Birth for Pregnant Women who Received Flu Vaccination

Women who were vaccinated for H1N1 in 2009 were less likely to have their children pre-term.

Pregnant women who received the H1N1 influenza vaccine during the 2009 pandemic were less likely to have premature babies, and their babies weighed more on average.

Influenza infection during pregnancy is associated with adverse infant outcomes such as preterm birth. Emory researchers from the Rollins School of Public Health, in a joint study with Kaiser Permanente of Georgia and the Mid-Atlantic States, evaluated the effectiveness of the H1N1 influenza vaccine in pregnant women against adverse infant outcomes during the 2009 pandemic. They compared birth outcomes among pregnant women who received the vaccine to those among pregnant women who were not vaccinated.

The researchers used de-identified electronic medical records for 3,327 women enrolled in Kaiser Permanente managed care organization sites between April 2009 and April 2010. The study looked at whether women got the H1N1 influenza vaccine during pregnancy and their birth outcomes such as premature birth and birth weight. Overall findings showed that vaccinated mothers were less likely to deliver their babies prematurely. On average, infants of vaccinated mothers also weighed more at birth than infants born to unvaccinated mothers.

"Our findings confirm the importance of receiving the influenza vaccine during pregnancy in order to protect the infant's health," explains Jennifer Richards, MPH, first author of the study. "Previous studies have shown that seasonal influenza vaccination may prevent preterm birth. This study shows that moms who were vaccinated during the H1N1 pandemic were less likely to have premature babies."

Influenza infection is especially dangerous for pregnant women. It increases risk of adverse infant outcomes, and of complications such as hospitalization for flu. During the 2009 H1N1 influenza pandemic, pregnant women in the U.S. experienced higher influenza-associated morbidity and mortality in comparison to the general population. Getting the flu vaccine during pregnancy can not only help to prevent infection for the mother, but studies have shown that it also protects the fetus and infant after birth.

"There is always an understandable heightened sense of caution by pregnant women," explains senior study author Saad B. Omer, PhD, assistant professor of global health at Rollins and an affiliate investigator at Kaiser Permanente Georgia. "Getting vaccinated has proven to be the best protection. Our study supports the U.S. policy to prioritize pregnant moms to receive the influenza vaccine."

Read more here

Can Low Birth Weight Raise Autism Risk?

After studying data on more than 3,700 pairs of identical twins, researchers from Northwestern University found that low birth weight was associated with more than triple the risk for autism spectrum disorder among twins in which autism only affected one of the children.

"That only one twin is affected by ASD [autism spectrum disorder] in some identical twin pairs suggests that environmental factors may play a role either independently or in interaction with autism risk genes," study author Molly Losh, director of Northwestern's Neurodevelopmental Disabilities Laboratory, said in a university news release.

"Our study of discordant twins -- twin pairs in which only one twin was affected by ASD -- found birth weight to be a very strong predictor of autism spectrum disorder," she added.

The study, which was released online in advance of publication in an upcoming print issue of the journal Psychological Medicine, used data from the Swedish Twin Registry's Child and Adolescent Twin Study.

In analyzing twins in which one baby was more than 14 ounces, or at least 15 percent heavier at birth than the other, the researchers found the risk for autism rose 13 percent for every 3.5 ounce drop in birth weight.

The study results suggested that birth weight could play a role in the complex causes of autism by interacting with a child's underlying genetic predisposition, or likelihood, of developing the condition, the researchers said.

Losh added that because autism is a developmental disorder involving early brain development, prenatal and perinatal environmental factors, such as birth weight, may be especially important.

The researchers noted, however, their findings may not apply to children who are not part of a multiple-birth pregnancy.

While the study found an association between birth weight and autism risk, it did not prove a cause-and-effect relationship.

Read more: http://www.nlm.nih.gov/medlineplus/news/fullstory_121145.html

Another Clue in the Mystery of Autism

Although the genetic basis of autism is now well established, a growing body of research also suggests that environmental factors may play a role in this serious developmental disorder affecting nearly one in 100 children. Using a unique study design, a new study suggests that low birth weight is an important environmental factor contributing to the risk of autism spectrum disorder (ASD).

"Our study of discordant twins -- twin pairs in which only one twin was affected by ASD -- found birth weight to be a very strong predictor of autism spectrum disorder," said Northwestern University researcher Molly Losh. Losh, who teaches and conducts research in Northwestern's School of Communication, is lead author of the study that will be published in the journalPsychological Medicine and is now available online.

Prior twin studies have shown that when one identical twin had ASD, the other twin was much more likely to have ASD than not. "Because identical twins share virtually 100 percent of their genes, this is strong evidence for the role of genetics in autism," said Losh. "Yet it is not 100 percent the case that ASD affects both identical twins in a twin pair."

"That only one twin is affected by ASD in some identical twin pairs suggests that environmental factors may play a role either independently or in interaction with autism risk genes," she added. "And because autism is a developmental disorder impacting brain development early on, it suggests that prenatal and perinatal environmental factors may be of particular importance."

The researchers found that lower birth weight more than tripled the risk for autism spectrum disorder in identical twin pairs in which one twin had ASD and the other did not.

To control for shared genetic and environmental factors, the researchers used a co-twin control study design in which the ASD-affected twin served as the case and the unaffected twin served as the control. They found the risk for autism spectrum disorder rose 13 percent for every 100 gram- (3.5 ounce-) decrease in birth weight.

"There's been a great deal of misinformation about the causes of autism -- from the 1950s misconception that the distant maternal behavior of what were dubbed "refrigerator mothers" was at fault to the ill-informed myth that vaccines can cause autism," said Losh.

Losh and her colleagues' findings add to a growing body of knowledge about the complex causes of autism and suggest that birth weight could be one of the environmental features that interacts with underlying genetic predisposition to autism.

Losh, who directs Northwestern's Neurodevelopmental Disabilities Laboratory, warned that the findings from twin studies might not extend to singletons, as the prenatal and perinatal conditions for twins and singletons differ in important ways.

The researchers studied a population-based sample of 3,725 same-sex twin pairs that were part of the Swedish Twin Registry's Child and Adolescent Twin Study that was directed by Paul Lichtenstein of Sweden's Karolinska Institute. The discordant twins they studied were pairs in which one twin was more than 400 grams (about 14 ounces) or at least 15 percent heavier at birth than the other.

Read more: http://www.sciencedaily.com/releases/2012/01/120119143334

Low Birthweight May Take A Toll On Cognitive Abilities Later In Life

A new, Finland-based study published in the journal Neurology on Monday suggests that very low-birthweight babies -- those under 3.3 pounds -- scored lower than normal birthweight babies when researchers considered their general intelligence, attention, visual memory and executive functioning as adults. The latest report joins prior studies that have suggested that severely preterm babies do worse on neurocognitive tests.

To look at the potential impact of birthweight on the brain, the authors of the new study compared approximately 100 adults with very low birthweight and approximately 100 who had not had very low birthweight.

"The most significant finding is that the differences we found persist into young adulthood and characterize a wide range of cognitive abilities," said Katri Raikkonen of the Institute of Behavioral Sciences at the University of Helsinki and one of the study's authors.

The researchers paid particular attention to executive function, which the National Center for Learning Disabilities defines as a set of mental processes used to perform activities such as planning, organizing, strategizing and paying attention to details.

In doing so, they found that the low-birthweight adults scored worse on tests looking at things like psychomotor speed, attention and distractibility.

According to Raikkonen, one potential explanation is the potential for brain injuries among preterm babies, which can occur from inadequate oxygen. She told HuffPost that the brain's plasticity -- its capacity to change in the wake of adverse events -- may not fully compensate for those early injuries.

But not all of the very low-birthweight babies looked at in the study were born premature, indicating the findings should not be extrapolated broadly to all babies born preterm, cautioned Dr. Michael Katz, senior vice president of research and grants at the March of Dimes.

"In as much as there were a small number of those [very low birth weight] babies who were born preterm, there appears to be some connection," Katz said. "But it leaves the question: Is the influence on cognitive abilities because of weight or because of low gestational age?"

What Katz said is clear is the fact that severely premature infants may have significant intellectual impairment, but that is highly individualized. The brain, he explained, continues developing long after birth. Some very low-birthweight and preterm babies may grow up with neurocognitive impairments or issues, others may not.

And that, according to Discenza, is where parents of preterm and very low-birthweight babies, like herself, could use help.

"These parents are so overwhelmed and we need to work a lot harder with them," she said, allowing that she has seen some uptick in awareness of these issues since her daughter was born.

"Every one of these low-birthweight babies should be qualifying for early intervention automatically," Discenza argued. "The reality is, these babies are at risk."

Read more: http://www.huffingtonpost.com/2011/12/05/low-birthweight-may-take-a-toll-on-cognitive-abilities-later_n_1129820.html