Family Dinner and Adolescent Overweight

Objective: The purpose of this study was to examine both cross‐sectional and longitudinal associations between frequency of family dinner and overweight status in a large sample of 9‐ to 14‐year‐old children. Research Methods and Procedures: We studied a cohort of 7784 girls and 6647 boys, 9 to 14 years of age at baseline in 1996, participating in the Growing Up Today Study. From annual mailed surveys, we calculated BMI from self‐reported height and weight and assessed frequency of family dinner over the previous year. We defined “overweight” as age‐ and sex‐specific BMI >85th percentile. We performed multiple logistic regression analyses; the longitudinal analyses assessed the association of previous year family dinner consumption with 1‐year incidence of becoming overweight, using prospective data from 1996 through 1999. Results: At baseline in 1996, 16% of participants had family dinner “never or some days,” 40% on “most days,” and 44% “every day.” Across these categories, overweight prevalence for girls was 19.4%, 16.6%, and 16.7% and for boys was 24.6%, 23.3%, and 22.7%, respectively. In cross‐sectional analyses, adjusting for potential confounders, the odds of being overweight was 0.85 [95% confidence interval (CI): 0.76, 0.96] among children who ate family dinner on “most days” or “every day” compared with those who ate family dinner “never or some days.” In longitudinal multivariate models, the odds ratios between previous year frequency of eating family dinner and 1‐year incidence of becoming overweight were 0.95 (95% CI: 0.78, 1.16) and 1.04 (95% CI: 0.85, 1.27) for children who ate family dinner on “most days” and “every day,” respectively, compared with those who ate family dinner “never or some days.” Discussion: The frequency of eating family dinner was inversely associated with overweight prevalence at baseline but not with likelihood of becoming overweight in longitudinal analyses.     

Associations of Maternal Diabetes During Pregnancy with Overweight in Offspring: Results from the Prospective TEDDY Study

Objective: This study aimed to determine the relationship between different forms of, and potential pathways between, maternal diabetes and childhood obesity at different ages. Methods: Prospective cohort data from The Environmental Determinants of Diabetes in the Young (TEDDY) study, which was composed of 5,324 children examined from 0.25 to 6 years of age, were analyzed. Cross‐sectional and longitudinal analyses taking into account potential confounders and effect modifiers such as maternal prepregnancy BMI and birth weight z scores were performed. Results: Offspring of mothers with gestational diabetes mellitus (GDM) or type 1 diabetes mellitus (T1DM) showed a higher BMI standard deviation score and increased risk for overweight and obesity at 5.5 years of age than offspring of mothers without diabetes. While these associations could be substantially explained by maternal prepregnancy BMI in offspring of mothers with GDM, significant associations disappeared after adjustment for birth weight z scores in offspring of T1DM mothers. Furthermore, overweight risk became stronger with increasing age in offspring of mothers with diabetes compared with offspring of mothers without diabetes. Conclusions: Maternal diabetes is associated with increased risk of offspring overweight, and the association appears to get stronger as children grow older. Indeed, intrauterine exposure to maternal T1DM may predispose children to later obesity through increased birth weight, while maternal BMI is more important in children exposed to GDM.     

Association of maternal lifestyles including smoking during pregnancy with childhood obesity

Objective: To examine the extent to which maternal smoking during early pregnancy and other prepregnancy lifestyle habits are associated with obesity and overweight in 5‐year‐old Japanese children. Research Method and Procedures: We studied 1417 mother‐child pairs enrolled in Project Enzan—a prospective cohort study. The dependent variables, childhood overweight and obesity, were defined with an international cut‐off value. Maternal smoking during early pregnancy and other prepregnancy lifestyle habits were used as independent variables. Results: Maternal smoking habits were associated with overweight in the 5‐year‐old children [adjusted odds ratio (OR): 2.15; 95% confidence interval (CI): 1.12 to 4.11]. Maternal sleep duration of ≥8 h/d negatively affected childhood overweight (adjusted OR: 0.71; 95% CI: 0.49 to 1.04). Children whose mothers skipped breakfast were likely to become overweight (adjusted OR: 1.78; 95% CI: 1.14 to 2.77). The results of childhood obesity analysis were similar to those of childhood overweight analysis. Discussion: The results of this study suggest that there are effects of smoking during early pregnancy and other maternal lifestyle habits on the onset of childhood obesity in Japan. Therefore, interventions in maternal lifestyle habits are required to prevent childhood obesity, and these interventions should be initiated before pregnancy.     

Additive Interactions of Maternal Prepregnancy BMI and Breast‐feeding on Childhood Overweight

Objective: To examine the interactions of maternal prepregnancy BMI and breast‐feeding on the risk of overweight among children 2 to 14 years of age. Research Methods and Procedures: The 1996 National Longitudinal Survey of Youth, Child and Young Adult data in the United States were analyzed (n = 2636). The weighted sample represented 51.3% boys, 78.0% whites, 15.0% blacks, and 7.0% Hispanics. Childhood overweight was defined as BMI ≥95th percentile for age and sex. Maternal prepregnancy obesity was determined as BMI ≥30 kg/m². The duration of breast‐feeding was measured as the weeks of age from birth when breast‐feeding ended. Results: After adjusting for potential confounders, children whose mothers were obese before pregnancy were at a greater risk of becoming overweight [adjusted odds ratio (OR), 4.1; 95% confidence interval (CI), 2.6, 6.4] than children whose mothers had normal BMI (<25 kg/m²; p < 0.001 for linear trend). Breast‐feeding for ≥4 months was associated with a lower risk of childhood overweight (OR, 0.6; 95% CI, 0.4, 1.0; p = 0.06 for linear trend). The additive interaction between maternal prepregnancy obesity and lack of breast‐feeding was detected (p < 0.05), such that children whose mothers were obese and who were never breast‐fed had the greatest risk of becoming overweight (OR, 6.1; 95% CI, 2.9, 13.1). Discussion: The combination of maternal prepregnancy obesity and lack of breast‐feeding may be associated with a greater risk of childhood overweight. Special attention may be needed for children with obese mothers and lack of breast‐feeding in developing childhood obesity intervention programs.     

The Influence of Maternal Quality on Brood Sex Allocation in the Small Carpenter Bee,Ceratina calcarata

In the twig‐nesting carpenter bee, Ceratina calcarata, body size is an important component of maternal quality, smaller mothers producing significantly fewer and smaller offspring than larger mothers. As mothers precisely control the sex and size of each offspring, smaller mothers might compensate by preferentially allocating their investment towards sons. We investigated whether variation in maternal quality leads to variation in sex allocation patterns. At the population level, the numerical sex ratio was 57% male‐biased (1.31 M/F), but the investment between the sexes was balanced (1.02 M/F), because females are 38% larger than males (1.28 F/M). Maternal body size explained both sex allocation pattern and size variation among offspring: larger mothers invested more in individual progeny and produced more female offspring than smaller mothers. Maternal investment in offspring of both sexes decreased throughout the season, probably as a result of increasing maternal wear and age. The exception to this pattern was the curious production of dwarf females in the first two brood cell positions. We suggest that the sex ratio distribution reflects the maternal body size distribution and a constraint on small mothers to produce small broods. This leads to male‐biased allocation by small females, to which large mothers respond by biasing their allocation towards daughters.     

Maternal Gestational Diabetes Mellitus and Offspring Body Mass Index from 1 to 4 Years

ObjectiveUsing the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria to diagnose gestational diabetes mellitus (GDM), the association between GDM and offspring body mass index (BMI) gains in early childhood in China remains unclear. We aimed to assess the association between GDM diagnosed by the IADPSG criteria and BMI gain and the risk for overweight/obesity in offspring from 1 to 4 years.MethodsThis prospective cohort study was based on the healthcare records data from the Medical Birth Registry in Xiamen, China. We included 10,412 mother-child pairs tested for GDM using IADPSG criteria.ResultsA total of 1,786 (17.2%) offspring were exposed to GDM. The offspring exposed to GDM had higher mean BMI Z-score (difference, 0.07; 95% confidence interval [CI], 0.02 to 0.12) and risk for overweight/obesity (odds ratio [OR], 1.22; 95% CI, 1.06 to 1.40) compared to those unexposed to GDM from 1 to 4 years of age. However, after adjustment for maternal pre-pregnancy BMI (Model 2), these associations attenuated towards the null (difference in BMI Z-score, 0.02; 95% CI, -0.03 to 0.07; OR for overweight/obesity, 1.09; 95% CI, 0.95 to 1.25).ConclusionThe associations between GDM diagnosed using IADPSG criteria and BMI Z-score and the risk for overweight/obesity in offspring at the age of 1 to 4 years were largely explained by maternal pre-pregnancy BMI. Reducing the prevalence of childhood overweight and obesity in China should focus on maternal weight status before pregnancy, in addition to glycemia during pregnancy.     

Associations of Maternal Prenatal Smoking with Child Adiposity and Blood Pressure

Objective: To examine the extent to which maternal prenatal smoking is associated with adiposity, central adiposity, and blood pressure in 3‐year‐old children. Research Methods and Procedures: We studied 746 mother‐child pairs in Project Viva, a prospective cohort study, and categorized mothers as never, early pregnancy, or former smokers. Main outcome measures were overweight (BMI for age and sex > 85th percentile), BMI z‐score, sum of subscapular (SS) and triceps (TR) skinfolds, SS:TR skinfold ratio, and systolic blood pressure (SBP). Results: One hundred sixty‐one (22%) mothers quit smoking before pregnancy, 71 (10%) smoked in early pregnancy, and 514 (69%) never smoked. At age 3 years, 204 (27%) children were overweight. On multivariable analysis, compared with children of never smokers, children of early pregnancy smokers had an elevated risk for overweight [odds ratio (OR), 2.2; 95% confidence interval (CI), 1.2, 3.9] and higher BMI z‐score (0.30 units; 95% CI, 0.05, 0.55), SS + TR (2.0 mm; 95% CI, 0.9, 3.0), and SBP (2.4 mm Hg; 95% CI, ?0.1, 4.9). Children of former smokers were not more overweight (BMI z‐score, 0.02 units; 95% CI, ?0.15, 0.19) but had higher SBP (1.5 mm Hg; 95% CI, ?0.1, 3.2). We saw no relationship of smoking with central adiposity (SS:TR). Discussion: Former and early pregnancy smokers had children with somewhat higher SBP, but only early pregnancy smokers had children who were more overweight. Mechanisms linking smoking with child adiposity and blood pressure may differ. A long‐term impact of maternal smoking on offspring cardiovascular risk provides further reason to reduce smoking in women.     

Identification of an Obese Eating Style in 4‐year‐old Children Born at High and Low Risk for Obesity

This study tested whether children's eating behavior and parental feeding prompts during a laboratory test meal differ among children born at high risk (HR) or low risk (LR) for obesity and are associated with excess child weight gain. At 4 years of age, 32 HR children (mean maternal prepregnancy BMI = 30.4 kg/m²) and 29 LR children (maternal BMI = 19.6 kg/m²) consumed a test meal in which their eating behavior was assessed, including rate of caloric consumption, mouthfuls/min, and requests for food. Parental prompts for the child to eat also were measured at year 4, and child body composition was measured at ages 4 and 6 years. T‐tests, and logistic and multiple regression analyses tested study aims. Results indicated that HR and LR children did not differ in eating rate or parental feeding prompts. Greater maternal BMI, child mouthfuls of food/min, and total caloric intake/min during the test meal predicted an increased risk of being overweight or obese at age 6, whereas greater active mealtime was associated with a reduced risk of being overweight or obese. Regression analyses indicated that only mouthfuls of food/min predicted changes in BMI from 4 to 6 years, and mouthfuls of food/min and gender predicted 2‐year changes in sum of skinfolds and total body fat. Thus, a rapid eating style, characterized by increased mouthfuls of food/min, may be a behavioral marker for the development of childhood obesity.     

Maternal caloric restriction partially rescues the deleterious effects of advanced maternal age on offspring

While many studies have focused on the detrimental effects of advanced maternal age and harmful prenatal environments on progeny, little is known about the role of beneficial non‐Mendelian maternal inheritance on aging. Here, we report the effects of maternal age and maternal caloric restriction (CR) on the life span and health span of offspring for a clonal culture of the monogonont rotifer Brachionus manjavacas. Mothers on regimens of chronic CR (CCR) or intermittent fasting (IF) had increased life span compared with mothers fed ad libitum (AL). With increasing maternal age, life span and fecundity of female offspring of AL‐fed mothers decreased significantly and life span of male offspring was unchanged, whereas body size of both male and female offspring increased. Maternal CR partially rescued these effects, increasing the mean life span of AL‐fed female offspring but not male offspring and increasing the fecundity of AL‐fed female offspring compared with offspring of mothers of the same age. Both maternal CR regimens decreased male offspring body size, but only maternal IF decreased body size of female offspring, whereas maternal CCR caused a slight increase. Understanding the genetic and biochemical basis of these different maternal effects on aging may guide effective interventions to improve health span and life span.     

The Effects of Consuming Frequent,Higher Protein Meals on Appetite and Satiety During Weight Loss in Overweight/Obese Men

The purpose of this study was to determine the effects of dietary protein and eating frequency on perceived appetite and satiety during weight loss. A total of 27 overweight/obese men (age 47 ± 3 years; BMI 31.5 ± 0.7 kg/m²) were randomized to groups that consumed an energy‐restriction diet (i.e., 750 kcal/day below daily energy need) as either higher protein (HP, 25% of energy as protein, n = 14) or normal protein (NP, 14% of energy as protein, n = 13) for 12 weeks. Beginning on week 7, the participants consumed their respective diets as either 3 eating occasions/day (3‐EO; every 5 h) or 6 eating occasions/day (6‐EO; every 2 h), in randomized order, for 3 consecutive days. Indexes of appetite and satiety were assessed every waking hour on the third day of each pattern. Daily hunger, desire to eat, and preoccupation with thoughts of food were not different between groups. The HP group experienced greater fullness throughout the day vs. NP (511 ± 56 vs. 243 ± 54 mm · 15 h; P < 0.005). When compared to NP, the HP group experienced lower late‐night desire to eat (13 ± 4 vs. 27 ± 4 mm, P < 0.01) and preoccupation with thoughts of food (8 ± 4 vs. 21 ± 4 mm; P < 0.01). Within groups, the 3 vs. 6‐EO patterns did not influence daily hunger, fullness, desire to eat, or preoccupation with thoughts of food. The 3‐EO pattern led to greater evening and late‐night fullness vs. 6‐EO but only within the HP group (P < 0.005). Collectively, these data support the consumption of HP intake, but not greater eating frequency, for improved appetite control and satiety in overweight/obese men during energy restriction‐induced weight loss.     

Metabolic Profile in Early Pregnancy Is Associated with Offspring Adiposity at 4 Years of Age: The Rhea Pregnancy Cohort Crete,Greece

ContextMaternal pre-pregnancy obesity may increase the risk of childhood obesity but it is unknown whether other metabolic factors in early pregnancy such as lipid profile and hypertension are associated with offspring cardiometabolic traits.ObjectiveOur objective was to investigate whether fasting lipid, glucose, and insulin levels during early pregnancy and maternal pre-pregnancy weight status, are associated with offspring adiposity measures, lipid levels and blood pressure at preschool age.ResultsPre-pregnancy overweight/obesity was associated with greater risk of offspring overweight/obesity (RR: 1.83, 95%CI: 1.19, 2.81), central adiposity (RR: 1.97, 95%CI: 1.11, 3.49), and greater fat mass by 5.10mm (95%CI: 2.49, 7.71) at 4 years of age. These associations were more pronounced in girls. An increase of 40mg/dl in fasting serum cholesterol levels in early pregnancy was associated with greater skinfold thickness by 3.30mm (95%CI: 1.41, 5.20) at 4 years of age after adjusting for pre-pregnancy BMI and several other confounders. An increase of 10mmHg in diastolic blood pressure in early pregnancy was associated with increased risk of offspring overweight/obesity (RR: 1.22, 95%CI: 1.03, 1.45), and greater skinfold thickness by 1.71mm (95% CI: 0.57, 2.86) at 4 years of age.ConclusionsMetabolic dysregulation in early pregnancy may increase the risk of obesity at preschool age.     

Ethnic differences in lifestyle and overweight in the Netherlands

Objective: To study the effects of lifestyle variables and socioeconomic status on overweight among native Dutch and immigrants in The Netherlands. Research Methods and Procedures: Data were used from a survey sample (N = 2551) of native Dutch and immigrant respondents (Surinamese/Antilleans, Turks, and Moroccans). BMI was calculated using self‐reported weight and height. Lifestyle variables such as modern food habits (take‐out food and eating out) and participating in sports were included, as well as socioeconomic and demographic background variables. Bivariate and ordinary least squares analyses were performed to study BMI and the determinants of overweight among the different groups. Results: All immigrant groups had a higher prevalence of overweight than the Dutch, except Moroccans. Men were overweight more frequently than women. Take‐out food, eating out, and fresh vegetables were related to a decrease in BMI, whereas convenience foods were related to an increase in BMI. For ready‐to‐eat meals, the results were mixed. In all groups, age was associated with a higher BMI, and a higher level of education was associated with a lower BMI. Immigrants participated in sports less frequently than native Dutch people. Discussion: One percent to 5% of the total public health costs can be attributed to costs for overweight‐related diseases. Public health policies should aim at stimulating healthy lifestyles and discouraging bad food habits through higher taxes on high‐calorie foods. In particular, Dutch immigrants should be encouraged to lose weight, because they have a higher risk for overweight‐related diseases.     

Maternal Prepregancy BMI and Lipid Profile during Early Pregnancy Are Independently Associated with Offspring's Body Composition at Age 5–6 Years: The ABCD Study

Background

There is growing evidence that disturbances in maternal metabolism and, subsequently, intrauterine conditions affect foetal metabolism. Whether this has metabolic consequences in offspring later in life is not fully elucidated. We investigated whether maternal pre-pregnancy body mass index (pBMI) is associated with offspring''s adiposity at age 5–6 years and whether this association is mediated by the mother''s lipid profile during early pregnancy.

Methods

Data were derived from a multi-ethnic birth cohort, the Amsterdam Born Children and their Development (ABCD) study (inclusion 2003–2004). During early gestation mothers completed a questionnaire during pregnancy (pBMI) and random non-fasting blood samples were analysed for total cholesterol (TC), triglycerides (TG), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and total free fatty acids (FFA) in early gestation. At age 5–6 years, child''s BMI, waist-to-height-ratio (WHtR) and fat% were assessed.

Results

Only non-diabetic mothers with at term-born children were included(n = 1727). Of all women, 15.1% were overweight(BMI: 25–29.9 kg/m2) and 4.3% were obese(BMI≥30 kg/m2). After adjustments for confounders, every unit increase in pBMI was linearly associated with various offspring variables: BMI(β 0.10; 95% CI 0.08–0.12), WHtR*100(β 0.13; 95% CI 0.09–0.17), fat%(β 0.21; 95% CI 0.13–0.29) and increased risk for overweight(OR:1.15; 95% CI 1.10–1.20). No convincing proof for mediation by maternal lipid profile during early gestation was found. Moreover, maternal FFA was associated with the child''s fat percentage, BMI and risk for overweight. Maternal ApoB and TC were positively associated with the offspring''s fat percentage and maternal TG was positively associated with their children''s WHtR.

Conclusions

Both pBMI and maternal lipids during early pregnancy are independently related to offspring adiposity.     

A Study on Mediation by Offspring BMI in the Association between Maternal Obesity and Child Respiratory Outcomes in the Amsterdam Born and Their Development Study Cohort

Background

A causal relationship between maternal obesity and offspring asthma is hypothesized to begin during early development, but no underlying mechanism for the found association is identified. We quantitatively examined mediation by offspring body mass index (BMI) in the association of maternal pre-pregnancy BMI on risk of asthma and wheezing during the first 7–8 years of life in a large Amsterdam born birth cohort.

Methods

For 3185 mother-child pairs, mothers reported maternal pre-pregnancy BMI and offspring outcomes “ever being diagnosed with asthma” and “wheezing in the past 12 months” on questionnaires. We measured offspring height and weight at age 5–6 years. We performed a multivariate log linear regression comparing outcomes in offspring of mothers with different BMI categories. For each category we quantified and tested mediation by offspring BMI and also investigated interaction by parental asthma.

Results

At the age of 7–8 years, 8% of the offspring ever had asthma and 7% had current wheezing. Maternal pre-pregnancy obesity was associated with higher risks of asthma (adjusted RR 2.32 (95% CI: 1.49–3.61) and wheezing (adjusted RR 2.16 (95% CI: 1.28–3.64). Offspring BMI was a mediator in the association between maternal BMI and offspring wheezing, but not for asthma. There was no interaction by parental asthma.

Conclusions

Maternal pre-pregnancy obesity was associated with higher risks of offspring asthma and wheezing. The association between maternal obesity and offspring wheezing was both direct and indirect (mediated) through the child’s own BMI.     

The Relationship Between Parent and Child Self‐Reported Adherence and Weight Loss

Objective: Better adherence to treatment strategies in family‐based behavioral weight control programs may lead to greater weight reduction and improved weight maintenance in youth. This study assessed the influence of child and parent self‐reported adherence to behavioral strategies on changes in 2‐year child and parent percentage overweight. Research Methods and Procedures: Participants included 8‐ to 12‐year‐old children in ≥ 85th BMI percentile and their parents from 110 families taking part in two family‐based randomized controlled weight control studies. This study examined whether self‐reported adherence to behavioral strategies measured at 24 months increased prediction of child and parent percentage overweight change through 24‐month follow‐up after accounting for other factors that may influence weight change. Results: Child adherence to weighing and to preplanning for celebrations where high‐fat foods are served and parent adherence to praising the child and modeling healthy eating habits predicted 24‐month child percentage overweight change (p < 0.001). Child adherence to recording food and calories and parent adherence to modeling healthy eating habits predicted 24‐month parent percentage overweight change (p < 0.001). In hierarchical regression models, child weighing and preplanning and parent modeling were significant (p < 0.01) incremental predictors (r² of 24.8%) of 24‐month child percentage overweight. Child recording and parent modeling were significant (p < 0.01) incremental predictors (r² of 14%) of parent 24‐month percentage overweight change. Discussion: Child and parent adherence to specific components of family‐based behavioral weight control treatment are independent predictors of long‐term child and parent percentage overweight change.     

Controlled study of critical parent and family factors in the obesigenic environment

Objective: Critical gaps remain in our understanding of the obesigenic family environment. This study examines parent and family characteristics among obese youth presenting for treatment in a clinic setting. Research Methods and Procedures: Families of 78 obese youth (BMI z‐score = 2.4; age, 8 to 16 years; 59% girls; 49% African‐American) were compared with 71 non‐overweight (BMI z‐score = ?0.02) demographically matched comparisons. Parents completed measures assessing family demographics, psychological distress (Symptom Checklist 90‐Revised), and family functioning both broadly (Family Environment Scale: Conflicted, Support, Control) and at mealtimes (About Your Child's Eating‐Revised: Mealtime Challenges, Positive Mealtime Interaction). Height and weight were obtained from all participants. Results: Compared with mothers and fathers of non‐overweight youth, parents of obese youth had significantly higher BMIs (p < 0.001). Mothers of obese youth reported significantly greater psychological distress (p < 0.01), higher family conflict (p < 0.05), and more mealtime challenges (p < 0.01). Less positive family mealtime interactions were reported by both mothers (p < 0.01) and fathers (p < 0.05) of obese youth. These group differences did not vary by child sex or race. Logistic regression analyses indicated that maternal distress and mealtime challenges discriminated between obese and non‐overweight youth after controlling for maternal BMI. Family conflict was explained, in part, by maternal distress. Discussion: Obese youth who present for treatment in a clinic setting are characterized by psychosocial factors at the parent and family level that differ from non‐overweight youth. These data are critical because they identify factors that may be serving as barriers to a family's or youth's ability to implement healthy lifestyle behaviors but that are potentially modifiable.     

Maternal influences on offspring phenotypes and sex ratios in a multi‐clutching lizard with environmental sex determination

Maternal and environmental factors are important sources of phenotypic variation because both factors influence offspring traits in ways that impact offspring and maternal fitness. The present study explored the effects of maternal factors (maternal body size, egg size, yolk‐steroid allocation, and oviposition‐site choice) and seasonally‐variable environmental factors on offspring phenotypes and sex ratios in a multi‐clutching lizard with environmental sex determination (Amphibolurus muricatus). Maternal identity had strong effects on offspring morphology, but the nature of maternal effects differed among successive clutches produced by females throughout the reproductive season (i.e. maternal identity by environment interactions). The among‐female and among‐clutch variation in offspring traits (including sex ratios) was not mediated through maternal body size, egg size, or variation in yolk steroid hormones. This lack of nongenetic maternal effects suggests that phenotypic variation may be generated by gene by environment interactions. These results demonstrate a significant genetic component to variation in offspring phenotypes, including sex ratios, even in species with environmental sex determination. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 256–266.     

Smoking during pregnancy and offspring fat and lean mass in childhood

Objective: Maternal smoking during pregnancy has been shown to be associated with obesity in the offspring, but findings have been based mainly on BMI, which is derived from height and weight. This study examined the association between maternal and partner smoking during pregnancy and offspring total fat, truncal fat, and lean mass in childhood. Research Methods and Procedures: Analysis was based on 5689 white singletons born in 1991–1992 and enrolled in the Avon Longitudinal Study of Parents and Children, with maternal smoking data recorded for at least one trimester in pregnancy and their own body composition assessed by DXA at mean age 9.9 years. Results: Smoking at any time during pregnancy was associated with higher offspring BMI [0.18 (95% confidence interval, 0.12 to 0.25) standard deviation units] and total fat mass [0.17 (95% confidence interval, 0.12 to 0.23) standard deviation units], after adjustment for age, sex, height, and height squared for total fat mass. These associations were not attenuated by adjustment for the confounding factors that were measured. Maternal smoking was also associated with lean mass and, to a lesser extent, truncal fat mass. Associations with partner's smoking were in the same direction but weaker than those of the mother's for all outcomes. Discussion: Maternal smoking at any time during pregnancy is associated with higher offspring total fat mass at mean age 9.9 years. However, as the associations with partner smoking were only a little weaker than those with maternal smoking, confounding by social factors rather than a direct effect of maternal smoking is a possible explanation.     

Pre-Pregnancy Body Mass Index in Relation to Infant Birth Weight and Offspring Overweight/Obesity: A Systematic Review and Meta-Analysis

Background

Overweight/obesity in women of childbearing age is a serious public-health problem. In China, the incidence of maternal overweight/obesity has been increasing. However, there is not a meta-analysis to determine if pre-pregnancy body mass index (BMI) is related to infant birth weight (BW) and offspring overweight/obesity.

Methods

Three electronic bibliographic databases (MEDLINE, EMBASE and CINAHL) were searched systematically from January 1970 to November 2012. The dichotomous data on pre-pregnancy overweight/obesity and BW or offspring overweight/obesity were extracted. Summary statistics (odds ratios, ORs) were used by Review Manager, version 5.1.7.

Results

After screening 665 citations from three electronic databases, we included 45 studies (most of high or medium quality). Compared with normal-weight mothers, pre-pregnancy underweight increased the risk of small for gestational age (SGA) (odds ratios [OR], 1.81; 95% confidence interval [CI], 1.76–1.87); low BW (OR, 1.47; 95% CI, 1.27–1.71). Pre-pregnancy overweight/obesity increased the risk of being large for gestational age (LGA) (OR, 1.53; 95% CI, 1.44–1.63; and OR, 2.08; 95% CI; 1.95–2.23), high BW (OR, 1.53; 95% CI, 1.44–1.63; and OR, 2.00; 95% CI; 1.84–2.18), macrosomia (OR, 1.67; 95% CI, 1.42–1.97; and OR, 3.23; 95% CI, 2.39–4.37), and subsequent offspring overweight/obesity (OR, 1.95; 95% CI, 1.77–2.13; and OR, 3.06; 95% CI, 2.68–3.49), respectively. Sensitivity analyses revealed that sample size, study method, quality grade of study, source of pre-pregnancy BMI or BW had a strong impact on the association between pre-pregnancy obesity and LGA. No significant evidence of publication bias was observed.

Conclusions

Pre-pregnancy underweight increases the risk of SGA and LBW; pre-pregnancy overweight/obesity increases the risk of LGA, HBW, macrosomia, and subsequent offspring overweight/obesity. A potential effect modification by maternal age, ethnicity, gestational weight gain, as well as the role of gestational diseases should be addressed in future studies.