Obesity, gestational diabetes, diet and excess fetal growth: Erin Graves' MSc thesis, under the supervision of Drs. Campbell, Hill, and Evers
Main Findings: This study found that the factors that impacted fetal growth were: high pre-pregnancy BMI, antidepressant use, excess weight gain, and abnormal blood sugar tolerance.
Summary: This study was intended to look at factors that affect a mother’s development of gestational diabetes and factors that contribute to the birth of a large infant. Data from the Prenatal Health Project were used, and women with overt diabetes were excluded. Five factors were analyzed in relation to infant birth weight; mother’s pre-pregnancy BMI, mother’s calorie and nutrient intake mid-pregnancy, Omega 3 fatty acid intake and vitamin D intake. It was found that the factors that impacted fetal growth were: pre-pregnancy BMI (greater than 25), antidepressant use, excess weight gain (greater than 40lbs) and abnormal blood sugar tolerance. They also found that properly treated gestational diabetes has no strong effect on the risk of having a large newborn. The factors that were identified as impacting a mother’s development of gestational diabetes were: pre-pregnancy BMI (greater than 25) and excess weight gain (greater than 40lbs). Each of these findings corresponds with the current literature available on the topics.
Population-based placental weight ratio distributions and determinants of placental weight ratio: Erin Macdonald's MSc thesis, under the supervision of Drs. Campbell, Natale (Ob/Gyn), Regnault (physiologist), and Koval (biostatistician)
Main findings: Cigarette smoking and gestational diabetes can cause an infant to be larger and cause the placenta weight ratio to increase, which could lead to further complications.
Summary: This study was completed to determine whether pregnancy conditions were associated with the placental weight ratio (PWR). This measurement is a comparison between the fetal and placental growth. A large PWR would represent a larger placenta, with a small PWR representing a smaller placenta relative to fetus size. This study found that infants that are small for their gestational age had higher PWR’s than babies that were average or large for gestational age. This study was able to identify risk factors for extreme PWR for each gestational age, many of which could lead to further complications. Mechanisms that cause an infant to be larger in size can also result in a higher PWR. Two such factors include cigarette smoking and gestational diabetes. Fetal hypoxia, having a fetus deprived of oxygen, also causes an increased PWR as a result of compensatory mechanisms. This study has been the first to log PWR’s across a population.
Determinants of Small for Gestational Age Birth at Term: Written by Dr. M. Karen Campbell along with Shannon Cartier, Bin Xie, George Kouniakis, Wenyi Huang, and Victor Han
Main findings: This study found that the factors associated with severely small for gestational age infants include maternal age over 35 years, maternal smoking during pregnancy, preeclampsia, threatened preterm labor and low placental weight.
Summary: The purpose of this study was to analyze factors that affect small infant size at birth (below the third percentile, and between the third and tenth percentile). Of the sample, 1.7% of the participants had infants that were categorized as severely small for gestational age, and 5.1% of the participants had infants that were considered moderately small for gestational age. Risk factors differed between these two groups. The majority of severely small for gestation age infants could be classified as growth restricted, whereas many of the moderately small for gestational age infants could be classified as biologically small. Factors associated with severely small infants include maternal age over 35 years, maternal smoking during pregnancy, preeclampsia, threatened preterm labor and low placental weight. Factors associated with moderately small infants included maternal pre-pregnancy BMI less than 18.5 and low placental weight. Interestingly, psychosocial factors were not important determinants of small infants in this sample.
Screening for autism spectrum disorder: the identification of a subgroup appropriate for screening with the Modified Checklist for Autism in Toddlers (M-CHAT): Brie Yama's MSc thesis under supervision of Drs. Campbell, Freeman, MacFabe and Zou
Main findings: All children whose mothers express concern about child development should have targeted screening for autism.
Summary: The purpose of this study was to examine the properties of the Modified Checklist for Autism in Toddlers (M-CHAT), a tool widely used to screen for Autism among young children. The outcomes of the study included identification of factors that increase the likelihood of having a positive M-CHAT. These include familial income, maternal education level, maternal depressive symptoms, sex, fever, parental concern for growth and development, walk in clinic visits and hospital admissions. One factor identified as a primary predictor was parental concern about child development. The findings suggest that all children whose mothers express concern about child development should have targeted screening for Autism. Targeted screening would decrease the amount of false positive screens, and allow for a more streamlined diagnosis process.