latest research

Aug. 2, 2009

Poor Sleep In Children May Have Prenatal Origins
Credit to ScienceDaily.com
 
A new study found that alcohol consumption during pregnancy and small body size at birth predict poorer sleep and higher risk of sleep disturbances in 8-year-old children born at term. Findings are clinically significant, as poor sleep and sleep disturbances in children are associated with obesity, depressive symptoms, attention deficit hyperactivity disorder, and poor neurobehavioral functioning.

Results indicate that children exposed prenatally to alcohol were 2.5 times more likely to have a short sleep duration of 7.7 hours or less and 3.6 times more likely to have a low sleep efficiency of 77.2 percent or less across all nights, independent of body size at birth and current maternal alcohol use.

Smaller body size at birth also was associated with poorer sleep and with a higher risk for clinically significant sleep disturbances among children born at term. More specifically, lower weight and shorter length at birth were associated with lower sleep efficiency, and a lower ponderal index (an indicator of fetal growth status) was associated with the presence of sleep disturbances.

In addition, children with short sleep duration were more likely to have been born via Caesarean section than were children sleeping longer (23.1 percent versus 8.4 percent respectively).
According to principal investigator Katri Räikkönen, PhD, in the department of psychology at the University of Helsinki, Finland, even low levels of weekly prenatal exposure to alcohol have adverse effects on sleep quantity and quality during childhood.

"The results were in accordance with the fetal origins of health and disease hypothesis and the many studies that have shown that adverse fetal environment may have lifelong influences on health and behavior," said Räikkönen. "However, this is among the few studies that have reported associations between birth variables and sleep quality and quantity among an otherwise healthy population of children."

The epidemiologic cohort study obtained data from 289 children born at term (from 37 to 42 weeks of gestation) between March and November 1998. Sleep duration and sleep efficiency (actual sleep time divided by the time in bed) were measured objectively by actigraphy at 8 years of age for an average of 7.1 days. Parents completed the Sleep Disturbance Scale for Children to report sleep problems and sleep disorder symptoms such as bedtime resistance and sleep disordered breathing.

Results show that the odds for low sleep efficiency increased by 70 percent for every standard deviation decrease in weight at birth and by more than 200 percent for every decrease in length. For every standard deviation decrease in ponderal index at birth, the risk of parent-reported sleep disorders increased by 40 percent. Associations were not confounded by sex, gestational length, prenatal and perinatal complications, body mass index (BMI) at eight years of age, asthma, allergies or parental socioeconomic status.

The authors report that small body size at birth may function as a crude marker of disturbances in the fetal environment, and it is associated with prematurity, intrauterine growth retardation, prenatal alcohol exposure and poorer sleep quality in children and young adults. Results demonstrate that among children born healthy and at full-term, a linear relationship exists between smaller body size at birth and poorer sleep quality eight years from birth.

Apr. 15, 2009

Snacking On High GI Foods During Late Pregnancy May Lead To The Birth Of A Heavier Baby With An Increased Risk Of Childhood Obesity
Credit to ScienceDaily.com

Mothers who snack on high GI (Glycaemic Index) foods like chocolate and white bread during later pregnancy may give birth to heavier babies with a greater risk of childhood obesity, according to new research published in the British Journal of Obstetrics and Gynaecology.

The research by scientists from the UCD Conway Institute at University College Dublin, Ireland, and the National Maternity Hospital (NMH) in Dublin, Ireland, into sheep models of pregnancy discovered that high GI snack diets among ewes during the third trimester of pregnancy resulted in a heavier birth weight and postnatal growth rate of newborn lambs.

According to the scientists, the sheep model used in the scientific study is instructive of the relationship between a human mothers’ diet, the birth weight of their child, and the risk of childhood obesity. In previous scientific studies, the sheep model has been shown to share many elements of pregnancy with the human model including metabolic function and nutrient transport.

For the past 40 years, sheep models have been used to investigate maternal–fetal interactions in humans because sheep have a body weight of 65 to 85 kg, a 17 day (average) reproductive cycle, and they usually have 1 or 2 lambs per pregnancy with a relatively long gestation period of 147 days. Sheep models are also amenable to reproduction, nutritional and surgical manipulation and can tolerate observations like ultrasound and tissue collections such as blood sampling.

“For the first time, in a sheep model, the findings show that ewes fed high glycaemic foods twice daily in addition to their normal meals, during the last trimester of pregnancy, gave birth to heavier lambs with a faster postnatal growth rate,” says Professor Alex Evans, Associate Professor of Animal Physiology at the UCD School of Agriculture, Food and Veterinary Medicine, at University College Dublin, one of the co-authors of the study.

“Our findings show that maternal hyperglycaemia stimulates the production of insulin and suggest that this has a positive effect on fetal growth,” he explains. “Changing the source and pattern of intake of maternal dietary carbohydrate may help reduce maternal and fetal trauma at parturition and reduce the risk of obesity related diseases among offspring in later life.”

The new scientific research findings published in the British Journal of Obstetrics and Gynaecology will prompt further investigations into the effects of high-glycaemic diets during pregnancy on the birth weight of children and the associated potential future risk of developing childhood obesity.

The Glycaemic Index (GI Index) is a scale of 0 – 100 which measures how a food raises blood glucose levels after it is eaten: dramatically, moderately or a little.

Higher GI values are given to foods that result in the most rapid rise in blood sugar once consumed. Many sweet and sugary foods have high GI but so too do starchy foods like potatoes and white bread. Glucose scores 100 on the GI Index, bananas score 52, and peanuts score 14. GIs of 70 or above are considered high, while GIs of 55 or below are considered low. Fish, pasta, milk, meat and most fruit and vegetables (except potatoes and watermelon) are low GI foods.