Maternal serum lipids during pregnancy and infant birth weight: the influence of prepregnancy BMI

Maternal obesity may be associated with metabolic factors that affect the intrauterine environment, fetal growth, and the offspring's long-term risk for chronic disease. Among these factors, maternal serum lipids play a particularly important role. Our objective was to estimate the influence of variation in maternal serum lipid levels on variation in infant birth weight (BW) in overweight/obese and normal weight women. In a prospective cohort of 143 gravidas, we measured maternal serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) at 6-10, 10-14, 16-20, 22-26, and 32-36 weeks gestation. Effects of maternal serum lipid levels on infant BW adjusted for gestational age at delivery (aBW) were analyzed using linear regression models. In analyses stratified by maternal prepregnancy BMI categorized as normal (≤25.0 kg/m(2)) and overweight/obese (>25.0 kg/m(2)), we found a significant (P < 0.05) inverse association between aBW and HDL-C at all time points starting at 10 weeks gestation in overweight/obese women. No significant effect was found in normal weight women. In contrast, increased maternal serum TG was significantly associated with increased aBW only for normal weight women at 10-14 and 22-26 weeks gestation. Variation in aBW is not associated with variation in maternal serum TC or LDL-C for either stratum at any time point. We postulate that such differences may be involved in the "physiological programming" that influences later risk of chronic disease in the infants of overweight/obese mothers.     

Modeling the potential public health impact of prepregnancy obesity on adverse fetal and infant outcomes

Objective: Approximately one‐third of US reproductive‐aged women are obese, and prepregnancy obesity is a strong risk factor for adverse fetal and infant outcomes. The annual number of preventable adverse fetal and infant outcomes associated with prepregnancy obesity in the US was estimated. Design and Methods: Adverse fetal and infant outcomes for which statistically significant associations with prepregnancy obesity had been reported by peer‐reviewed meta‐analyses, which included fetal deaths and nine different major birth defects, were assessed. The true prevalence of prepregnancy obesity was estimated by multiplying self‐reported prepregnancy obesity by a bias factor based on the difference between measured and self‐reported obesity in US adult women. A Monte Carlo simulation approach was used to model the attributable fraction and preventable number, accounting for uncertainty in the estimates for: 1 strength of the association with obesity, 2 obesity prevalence, and 3 outcome prevalence. Results: Eliminating the impact of prepregnancy obesity would potentially prevent the highest numbers of four outcomes: fetal deaths (6,990; uncertainty interval [UI] 4,110‐10,080), congenital heart defects (2,850; UI 1,035‐5,065), hydrocephalus (490; UI 150‐850), and spina bifida (405; UI 305‐505). If 10% of women with prepregnancy obesity achieved a healthy weight before pregnancy or otherwise mitigated the impact of obesity, nearly 300 congenital heart defects and 700 fetal deaths per year could potentially be prevented. Conclusion: This simulation suggests that effective prevention strategies to reduce prepregnancy obesity or the risk associated with obesity could have a measurable impact on infant health in the US.     

Maternal transport and infant motor development in a captive group of lowland gorillas

Infant development and mother-infant interactions were studied in three group-living lowland gorilla infants through the first 18 months of life. Ten modes of maternal transport of infants were identified. Of these, tripedal walk and back-ride were used by all mothers. The other forms of transport were more idiosyncratic. Almost all forms of maternal transport had ceased by 18 months. Infant motor development was found to progress rapidly through the first six months of life, with most motor behaviors exhibited by this age. Beyond this, more specialized (e.g., aggressive) motor patterns appeared.     

Maternal obesity at conception programs obesity in the offspring

Risk of obesity in adult life is subject to programming during gestation. To examine whether in utero exposure to maternal obesity increases the risk of obesity in offspring, we developed an overfeeding-based model of maternal obesity in rats utilizing intragastric feeding of diets via total enteral nutrition. Feeding liquid diets to adult female rats at 220 kcal/kg(3/4) per day (15% excess calories/day) compared with 187 kcal/kg(3/4) per day for 3 wk caused substantial increase in body weight gain, adiposity, serum insulin, leptin, and insulin resistance. Lean or obese female rats were mated with ad libitum AIN-93G-fed male rats. Exposure to obesity was ensured to be limited only to the maternal in utero environment by cross-fostering pups to lean dams having ad libitum access to AIN-93G diets throughout lactation. Numbers of pups, birth weight, and size were not affected by maternal obesity. Male offspring from each group were weaned at postnatal day (PND)21 to either AIN-93G diets or high-fat diets (45% fat calories). Body weights of offspring from obese dams did not differ from offspring of lean dams when fed AIN-93G diets through PND130. However, offspring from obese dams gained remarkably greater (P < 0.005) body weight and higher % body fat when fed a high-fat diet. Body composition was assessed by NMR, X-ray computerized tomography, and weights of adipose tissues. Adipose histomorphometry, insulin sensitivity, and food intake were also assessed in the offspring. Our data suggest that maternal obesity at conception leads to fetal programming of offspring, which could result in obesity in later life.     

Maternal nutrition and the programming of obesity

The increasing incidence of obesity in the developed and developing world in the last decade has led to a need to define our understanding of the physiological mechanisms which can predispose individuals to weight gain in infancy, childhood and adulthood. There is now a considerable body of evidence which has shown that the pathway to obesity may begin very early in life, and that exposure to an inappropriate level of nutrition during prenatal and/or early postnatal development can predispose individuals to obesity in later life The brain is at the heart of the regulation of appetite and food preferences, and it is increasingly being recognised that the development of central appetitive structures is acutely sensitive to the nutritional environment both before and immediately after birth. This review will summarise the body of work which has highlighted the critical role of the brain in the early origins of obesity and presents some perspectives as to the potential application of these research findings in the clinical setting.     

Genetic analysis of motor milestones attainment in early childhood.

The age of attainment for four motor developmental traits, such as turning over, sitting up without support, pulling up to a standing position and walking without support, was examined in 822 children, including 626 siblings from families with 2 to 6 children, 68 pairs of dizygotic twins and 30 pairs of monozygotic twins. Correlation analysis, carried out separately for each type of sibship, showed the highest pairwise correlations in monozygotic twins and the lowest correlation in non-twin siblings for all motor milestones. Variance component analysis was used to decompose the different independent components forming the variation of the studied trait, such as genetic effect, common twin environment, common sib environment and residual factors. The results revealed that the major proportion of the total variance after adjustment for gestation age for the attainment of each motor skill, except pulling up to standing position, is explained by the common twin environment (50.5 to 66.6%), whilst a moderate proportion is explained by additive genetic factors (22.2 to 33.5%). Gestational age was found to be an important predictor of appearance of all motor milestones, affecting delay of 4.5 to 8.6 days for the attainment of the motor abilities for each week of earlier gestation. The age of attainment of the standing position was affected only by shared sibs environment (33.3% of the total variance) and showed no influence of either genetic or common twin environment. Phenotypic between trait correlations were high and significant for all studied traits (range between 0.40 and 0.67, P < 0.01 in all instances). Genetic cross correlations, however, were not easily interpreted and did not show clear variance trends among the different groups of children.     

Maternal serum leptin during pregnancy and infant birth weight: The influence of maternal overweight and obesity

Objective:

Few studies have examined whether the distinct metabolic patterns found in obese and nonobese pregnant women have different effects on the growing fetus. Our objective was to estimate the influence of longitudinal variation in maternal serum leptin levels on variation in infant birth weight in overweight/obese versus normal‐weight women.

Design and Methods:

In a prospective cohort of 286 gravidas, maternal weight and serum leptin levels at 6–10, 10–14, 16–20, 22–26, and 32–36 weeks gestation were measured. Effects of leptin levels on infant birth weight adjusted for gestational age at delivery (aBW) were analyzed using a linear regression model that accounted for the relationship of time‐varying predictors to the log‐transformed leptin concentrations.

Results:

Different relationships of aBW to maternal serum leptin and its rate of change across pregnancy were exhibited by overweight/obese and normal‐weight gravidas. For normal‐weight women, aBW is not associated with either the magnitude of the logarithm of the leptin concentration or with its rate of change in either the first or second half of pregnancy. Conversely, for overweight/obese women, an increase in the rate of change in maternal serum leptin in the second half of pregnancy is significantly associated with a decrease in aBW. This effect is distinct from that of maternal weight.

Conclusion:

Differences in the effect of maternal serum leptin on fetal growth between overweight/ obese and normal‐weight women suggest metabolic and physiologic heterogeneity between these groups. Such differences may be involved in the long‐term physiologic effects of the obese intrauterine environment on the health of the offspring.     

Maternal employment and childhood obesity in Russia

Existing research on childhood obesity shows that rising maternal employment is associated with increases in child weight. This paper aims to estimate the effect of maternal employment on childhood obesity in Russia, where obesity has been spreading quickly over the last 20 years. To address the endogeneity of maternal employment and estimate its effect on the weight outcomes of older siblings, I use plausibly exogenous variation in childcare enrolment for the youngest child in the household as an instrumental variable for maternal employment. Based on the Russian Longitudinal Monitoring Survey (RLMS-HSE), the results show that maternal employment leads to an increase in children’s BMI and in their probabilities of becoming overweight and obese. In exploring the potential underlying mechanisms, I find that maternal employment is related to less physical activity, to a higher probability of either watching TV or playing video games, and to poorer dietary habits among children.     

Comparison of three models predicting developmental milestones given environmental and individual variation

In all organisms, phenotypic variability is an evolutionary stipulation. Because the development of poikilothermic organisms depends directly on the temperature of their habitat, environmental variability is also an integral factor in models of their phenology. In this paper we present two existing phenology models, the distributed delay model and the Sharpe and DeMichele model, and develop an alternate approach, called the Extended von Foerster model, based on the age-structured McKendrick-von Foerster partial differential model. We compare the models theoretically by examining the biological assumptions made in the basic derivation of each approach. In particular, we focus on each model’s ability to incorporate variability among individuals as well as variability in the environment. When compared against constant temperaturemountain pine beetle (Dendroctonus ponderosae Hopkins) laboratory developmental data, the Extended von Foerster model exhibits the highest correlation between theory and observation.     

Maternal obesity and morbid obesity: The risk for birth defects in the offspring

BACKGROUND : The objective of this study was to assess, in a large data set from Swedish Medical Health Registries, whether maternal obesity and maternal morbid obesity were associated with an increased risk for various structural birth defects. METHODS : The study population consisted of 1,049,582 infants born in Sweden from January 1, 1995, through December 31, 2007, with known maternal weight and height data. Women were grouped in six categories of body mass index (BMI) according to World Health Organization classification. Infants with congenital birth defects were identified from three sources: the Swedish Medical Birth Registry, the Register of Birth Defects, and the National Patient Register. Maternal age, parity, smoking, and year of birth were thought to be potential confounders and were included as covariates in the adjusted odds ratio analyses. RESULTS : Ten percent of the study population was obese. Morbid obesity (BMI ≥ 40) occurred in 0.7%. The prevalence of congenital malformations was 4.7%, and the prevalence of relatively severe malformations was 3.2%. Maternal prepregnancy morbid obesity was associated with neural tube defects OR 4.08 (95% CI 1.87–7.75), cardiac defects OR 1.49 (95% CI 1.24–1.80), and orofacial clefts OR 1.90 (95% CI 1.27–2.86). Maternal obesity (BMI ≥ 30) significantly increased the risk of hydrocephaly, anal atresia, hypospadias, cystic kidney, pes equinovarus, omphalocele, and diaphragmatic hernia. CONCLUSION : The risk for a morbidly obese pregnant woman to have an infant with a congenital birth defect is small, but for society the association is important in the light of the ongoing obesity epidemic. Birth Defects Research (Part A), 2010. © 2009 Wiley‐Liss, Inc.     

Maternal and developmental toxicity of ayahuasca in Wistar rats

INTRODUCTION: Ayahuasca is a psychotropic plant beverage initially used by shamans throughout the Amazon region during traditional religious cult. In recent years, ayahuasca has also been used in ceremonies of a number of modern syncretic religious groups, including pregnant women. However, no documented study has been performed to evaluate the risk of developmental toxicity of ayahuasca. METHODS: In the present work, maternal and developmental toxicity was evaluated in Wistar rats. Ayahuasca was administered to pregnant rats in three different doses [the equivalent typical dose (TD) administered to humans, five‐fold TD and 10‐fold TD] during the gestational period (6–20 days). RESULTS: Dams treated with the highest ayahuasca dose showed maternal toxicity with decrease of weight gain and food intake. Visceral fetal findings were observed in all treatment groups. Skeletal findings were observed in the intermediate‐ and high‐dose groups. The fetuses deriving from the highest dose group also presented a decrease in body weight. CONCLUSIONS: From these results, it is possible to conclude that there is a risk of maternal and developmental toxicity following ayahuasca exposure and that the level of toxicity appears to be dose‐dependent. Birth Defects Res (Part B) 89:207–212, 2010. © 2010 Wiley‐Liss, Inc.     

Maternal and paternal periods in the development of infant Callimico goeldii

The paternal-maternal-infant interactions of contact and nursing are reported from extensive longitudinal observations on two successive Callimico births in one family. For the first two weeks, the maternal period, the infant clings exclusively to the female. In the third week the infant shifts abruptly to the male. Subsequently, during the paternal period most of the maternal-infant contact involves nursing. The infant Callimico remains almost totally dependent until week 6, but even in week 11 it spends less than 50% of the time off a parent.     

Maternal weight change from prepregnancy to 18 months postpartum and subsequent risk of hypertension and cardiovascular disease in Danish women: A cohort study

BackgroundOne-fourth of women experience substantially higher weight years after childbirth. We examined weight change from prepregnancy to 18 months postpartum according to subsequent maternal risk of hypertension and cardiovascular disease (CVD).Methods and findingsWe conducted a cohort study of 47,966 women with a live-born singleton within the Danish National Birth Cohort (DNBC; 1997–2002). Interviews during pregnancy and 6 and 18 months postpartum provided information on height, gestational weight gain (GWG), postpartum weights, and maternal characteristics. Information on pregnancy complications, incident hypertension, and CVD was obtained from the National Patient Register. Using Cox regression, we estimated adjusted hazard ratios (HRs; 95% confidence interval [CI]) for hypertension and CVD through 16 years of follow-up. During this period, 2,011 women were diagnosed at the hospital with hypertension and 1,321 with CVD. The women were on average 32.3 years old (range 18.0–49.2) at start of follow-up, 73% had a prepregnancy BMI <25, and 27% a prepregnancy BMI ≥25. Compared with a stable weight (±1 BMI unit), weight gains from prepregnancy to 18 months postpartum of >1–2 and >2 BMI units were associated with 25% (10%–42%), P = 0.001 and 31% (14%–52%), P < 0.001 higher risks of hypertension, respectively. These risks were similar whether weight gain presented postpartum weight retention or a new gain from 6 months to 18 months postpartum and whether GWG was below, within, or above the recommendations. For CVD, findings differed according to prepregnancy BMI. In women with normal-/underweight, weight gain >2 BMI units and weight loss >1 BMI unit were associated with 48% (17%–87%), P = 0.001 and 28% (6%–55%), P = 0.01 higher risks of CVD, respectively. Further, weight loss >1 BMI unit combined with a GWG below recommended was associated with a 70% (24%–135%), P = 0.001 higher risk of CVD. No such increased risks were observed among women with overweight/obesity (interaction by prepregnancy BMI, P = 0.01, 0.03, and 0.03, respectively). The limitations of this observational study include potential confounding by prepregnancy metabolic health and self-reported maternal weights, which may lead to some misclassification.ConclusionsPostpartum weight retention/new gain in all mothers and postpartum weight loss in mothers with normal-/underweight may be associated with later adverse cardiovascular health.

Helene Kirkegaard and co-workers study maternal weight changes and cardiovascular risk over 16 years of follow-up.     

Development of captive bongos (Tragelaphus eurycerus): Activity budgets and developmental milestones

The development of changes in visual orientation, posture, activity budgets, and behavioral milestones was examined in five bongo calves which were observed from birth to 4 or 6 months of age. The only significant change in the calves' visual orientation was an increase in orientation to food. Reclining declined significantly over weeks, while standing increased and moving did not change. Overall, stationary behaviors dominated the activity budget, but decreased significantly over the study. The category that included locomotion, object exploration, and auto-play did not change, while forage and rumination increased significantly. Contrary to expectation, the decline in suckling was not significant. Affiliative interactions with the dam decreased significantly during the study, but increases in affiliation with other bongos were not significant. Levels of agonistic behavior between the calves and their dams and other herd members were low throughout the study, and did not change significantly. One female calf achieved several developmental milestones later than the others. It is suggested that these differences may have been influenced by the dominance status of her dam. The results conform to the general developmental pattern of “hider” bovids. Bongos, however, show somewhat different patterns of social development than eland, which are reported to be more precocial in expression of aggressive and sexual behaviors. © 1992 Wiley-Liss, Inc.