Offspring Body Mass Research Articles

Preconceptional diet manipulation and fetus number can influence placenta endocrine function in sheep

Changes in maternal nutrition during pregnancy can result in profound effects on placental function and fetal development. Although the preconceptional period holds the potential to reprogram embryonic and placental development, little is known regarding the effects of premating nutritional manipulation on placental function and fetal and postnatal offspring growth. To test this, Polypay-Dorset sheep (n = 99) were assigned to 1 of 3 nutritional treatments (n = 33/treatment) receiving 50% (UN: undernutrition), 100% (C: control), or 200% (ON: overnutrition) of maintenance energy requirements for 21 d before mating during April–May (increasing photoperiod). Thereafter, diets were the same across groups. We evaluated maternal reproductive variables and maternal and offspring weight and body mass index through weaning. Maternal plasma was collected through pregnancy until postnatal day 1 to assay pregnancy-associated glycoproteins (PAGs) and progesterone. Fertility rate was similar among treatments, but ON females had a higher reproductive rate (UN: 82%; C: 100%, ON: 145%). When correcting by total birth weight, twin pregnancies had lower PAGs and progesterone versus singleton pregnancies (P < 0.001). At birth, UN lambs were heavier than C lambs regardless of birth type (P < 0.01). Growth velocity, daily gain, and weaning weight were similar, but UN and ON females grew faster and were heavier at weaning versus C females. We demonstrated that a 3-wk preconceptional maternal undernutrition or overnutrition, when correcting by total birth weight, results in lower endocrine capacity in twin pregnancies. Preconceptional maternal undernutrition and overnutrition increased postnatal female lamb growth, suggestive of reprogramming of pathways regulating growth before conception. This highlights how preconceptional nutrition can result in marked sex-specific differences.

Associations Between Prenatal Cannabis Exposure and Childhood Outcomes

In light of increasing cannabis use among pregnant women, the US Surgeon General recently issued an advisory against the use of marijuana during pregnancy. To evaluate whether cannabis use during pregnancy is associated with adverse outcomes among offspring. In this cross-sectional study, data were obtained from the baseline session of the ongoing longitudinal Adolescent Brain and Cognitive Development Study, which recruited 11 875 children aged 9 to 11 years, as well as a parent or caregiver, from 22 sites across the United States between June 1, 2016, and October 15, 2018. Prenatal cannabis exposure prior to and after maternal knowledge of pregnancy. Symptoms of psychopathology in children (ie, psychotic-like experiences [PLEs] and internalizing, externalizing, attention, thought, and social problems), cognition, sleep, birth weight, gestational age at birth, body mass index, and brain structure (ie, total intracranial volume, white matter volume, and gray matter volume). Covariates included familial (eg, income and familial psychopathology), pregnancy (eg, prenatal exposure to alcohol and tobacco), and child (eg, substance use) variables. Among 11 489 children (5997 boys [52.2%]; mean [SD] age, 9.9 [0.6] years) with nonmissing prenatal cannabis exposure data, 655 (5.7%) were exposed to cannabis prenatally. Relative to no exposure, cannabis exposure only before (413 [3.6%]) and after (242 [2.1%]) maternal knowledge of pregnancy were associated with greater offspring psychopathology characteristics (ie, PLEs and internalizing, externalizing, attention, thought and, social problems), sleep problems, and body mass index, as well as lower cognition and gray matter volume (all |β| > 0.02; all false discovery rate [FDR]-corrected P < .03). Only exposure after knowledge of pregnancy was associated with lower birth weight as well as total intracranial volume and white matter volumes relative to no exposure and exposure only before knowledge (all |β| > 0.02; all FDR-corrected P < .04). When including potentially confounding covariates, exposure after maternal knowledge of pregnancy remained associated with greater PLEs and externalizing, attention, thought, and social problems (all β > 0.02; FDR-corrected P < .02). Exposure only prior to maternal knowledge of pregnancy did not differ from no exposure on any outcomes when considering potentially confounding variables (all |β| < 0.02; FDR-corrected P > .70). This study suggests that prenatal cannabis exposure and its correlated factors are associated with greater risk for psychopathology during middle childhood. Cannabis use during pregnancy should be discouraged.

Growing in the city: Urban evolutionary ecology of avian growth rates.

IntroductionRapid environmental change driven by urbanization offers a unique insight into the adaptive potential of urban‐dwelling organisms. Urban‐driven phenotypic differentiation is increasingly often demonstrated, but the impact of urbanization (here modelled as the percentage of impervious surface (ISA) around each nestbox) on offspring developmental rates and subsequent survival remains poorly understood. Furthermore, the role of selection on urban‐driven phenotypic divergence was rarely investigated to date.Methods and ResultsData on nestling development and body mass were analysed in a gradient of urbanization set in Warsaw, Poland, in two passerine species: great tits (Parus major) and blue tits (Cyanistes caeruleus). Increasing levels of impervious surface area (ISA) delayed the age of fastest growth in blue tits. Nestling body mass was also negatively affected by increasing ISA 5 and 10 days after hatching in great tits, and 10 and 15 days in blue tits, respectively. High levels of ISA also increased nestling mortality 5 and 10 days after hatching in both species. An analysis of selection differentials performed for two levels of urbanization (low and high ISA) revealed a positive association between mass at day 2 and survival at fledging.DiscussionThis study confirms the considerable negative impact of imperviousness—a proxy for urbanization level—on offspring development, body mass and survival, and highlights increased selection on avian mass at hatching in a high ISA environment.

Fetal exposure to phthalates and bisphenols and childhood general and organ fat. A population-based prospective cohort study.

Fetal exposure to phthalates and bisphenols might have long-lasting effects on growth and fat development. Not much is known about the effects on general and organ fat development in childhood. We assessed the associations of fetal exposure to phthalates and bisphenols with general and organ fat measures in school-aged children. In a population-based, prospective cohort study among 1128 mother-child pairs, we measured maternal urinary phthalate metabolites and bisphenol concentrations in first, second, and third trimester. Offspring body mass index, fat mass index by dual-energy X-ray absorptiometry, and visceral and pericardial fat indices and liver fat fraction were measured by magnetic resonance imaging at 10 years. After adjustment for confounders and correction for multiple testing, an interquartile range increase in first trimester phthalic acid concentrations remained associated with a 0.14 (95% confidence interval: 0.05, 0.22) standard deviation score increase in pericardial fat index. We also observed tendencies for associations of higher maternal low molecular weight phthalate urinary concentrations in second trimester with childhood pericardial fat index, but these were not significant after adjustment for multiple testing. High molecular weight phthalate, di-2-ethylhexyl phthalate, and di-n-octyl phthalate concentrations were not associated with childhood outcomes. Maternal urinary bisphenol concentrations were not associated with childhood adiposity. Maternal first trimester phthalic acid concentrations are associated with increased childhood pericardial fat index at 10 years of age, whereas maternal bisphenol concentrations are not associated with childhood adiposity. We did not find significant sex-specific effects. These findings should be considered as hypothesis generating and need further replication and identification of underlying mechanisms.

Parents' smoking onset before conception as related to body mass index and fat mass in adult offspring: Findings from the RHINESSA generation study.

Emerging evidence suggests that parents' preconception exposures may influence offspring health. We aimed to investigate maternal and paternal smoking onset in specific time windows in relation to offspring body mass index (BMI) and fat mass index (FMI). We investigated fathers (n = 2111) and mothers (n = 2569) aged 39-65 years, of the population based RHINE and ECRHS studies, and their offspring aged 18-49 years (n = 6487, mean age 29.6 years) who participated in the RHINESSA study. BMI was calculated from self-reported height and weight, and FMI was estimated from bioelectrical impedance measures in a subsample. Associations with parental smoking were analysed with generalized linear regression adjusting for parental education and clustering by study centre and family. Interactions between offspring sex were analysed, as was mediation by parental pack years, parental BMI, offspring smoking and offspring birthweight. Fathers' smoking onset before conception of the offspring (onset ≥15 years) was associated with higher BMI in the offspring when adult (β 0.551, 95%CI: 0.174-0.929, p = 0.004). Mothers' preconception and postnatal smoking onset was associated with higher offspring BMI (onset <15 years: β1.161, 95%CI 0.378-1.944; onset ≥15 years: β0.720, 95%CI 0.293-1.147; onset after offspring birth: β2.257, 95%CI 1.220-3.294). However, mediation analysis indicated that these effects were fully mediated by parents' postnatal pack years, and partially mediated by parents' BMI and offspring smoking. Regarding FMI, sons of smoking fathers also had higher fat mass (onset <15 years β1.604, 95%CI 0.269-2.939; onset ≥15 years β2.590, 95%CI 0.544-4.636; and onset after birth β2.736, 95%CI 0.621-4.851). There was no association between maternal smoking and offspring fat mass. We found that parents' smoking before conception was associated with higher BMI in offspring when they reached adulthood, but that these effects were mediated through parents' pack years, suggesting that cumulative smoking exposure during offspring's childhood may elicit long lasting effects on offspring BMI.

Gestational sleep deprivation is associated with higher offspring body mass index and blood pressure.

Study ObjectivesThe objective of this study was to evaluate the association between gestational sleep deprivation and childhood adiposity and cardiometabolic profile.MethodsData were used from two population-based birth cohorts (Rhea study and Amsterdam Born Children and their Development study). A total of 3,608 pregnant women and their children were followed up until the age of 11 years. Gestational sleep deprivation was defined as 6 or fewer hours of sleep per day, reported by questionnaire. The primary outcomes included repeated measures of body mass index (BMI), waist circumference, body fat, serum lipids, systolic and diastolic blood pressure (DBP) levels in childhood. We performed a pooled analysis with adjusted linear mixed effect and Cox proportional hazards models. We tested for mediation by birthweight, gestational age, and gestational diabetes.ResultsGestational sleep deprivation was associated with higher BMI (beta; 95% CI: 0.7; 0.4, 1.0 kg/m2) and waist circumference (beta; 95% CI: 0.9; 0.1, 1.6 cm) in childhood, and increased risk for overweight or obesity (HR; 95% CI: 1.4; 1.1, 2.0). Gestational sleep deprivation was also associated with higher offspring DBP (beta; 95% CI: 1.6; 0.5, 2.7 mmHg). The observed associations were modified by sex (all p-values for interaction < 0.05); and were more pronounced in girls. Gestational diabetes and shorter gestational age partly mediated the seen associations.ConclusionsThis is the first study showing that gestational sleep deprivation may increase offspring’s adiposity and blood pressure, while exploring possible mechanisms. Attention to glucose metabolism and preterm birth might be extra warranted in mothers with gestational sleep deprivation.

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

Objective: Using 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. Methods: This 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. Results: A 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). Conclusion: The 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. Abbreviations: BMI = body mass index; CI = confidence interval; GDM = gestational diabetes mellitus; IADPSG = International Association of Diabetes and Pregnancy Study Groups; LGA = large for gestational age; MBRX = Medical Birth Registry in Xiamen; OGTT = oral glucose tolerance test; OR = odds ratio.

Maternal Exposure to Electronic Cigarettes Causes Body Composition Alterations in Pups

Electronic cigarette (E‐cig) usage is promoted as a safe alternative to traditional smoking, even during pregnancy, but long‐term effects of vaping are still unknown. Maternal smoking during pregnancy has been well studied and shown to increase both body mass index and obesity within children later in life. However, the effects of vaping on the offspring of maternal E‐cig users remains poorly studied. We hypothesized that maternal vaping during pregnancy will also increase body mass and obesity in the mature offspring with E‐cig exposed rat dams.Pregnant Sprague Dawley dams were exposed to nicotine‐free E‐cig aerosol (E‐cig0), E‐cig aerosol containing 18 mg/ml of nicotine (E‐cig18), or ambient air (control). Maternal E‐cig exposure (Joyetech eGrip OLED using 5‐sec puff @ 17.5 W) consisted of 60 puffs over 1‐hour each day, 5 days/week, starting on gestational day 2 and continued until pups were weaned. Progeny themselves were never directly exposed to E‐cig aerosol. Dual energy X‐ray absorptiometry (DXA) was used for body composition analysis in male and female rat offspring at 31±1 weeks of age (Air n=16, E‐cig0 n=21, E‐cig18 n=19).In females, total body mass and lean body mass (LBM) was not different between the exposure groups, however fat mass (FM) was greater in E‐cig0 compared to air and E‐cig18 exposed groups (125±9 vs. 103±12 and 100±5 g, respectively, ANOVA p&lt;0.05). Percentage BF (%BF) was also greater in E‐cig0 compared to air and E‐cig18 (33±2 vs. 28±2 and 29±1 %, respectively, ANOVA p&lt;0.05). As expected, total body mass, LBM, and FM values were significantly lower in females than males (ANOVA p&lt;0.001), but no differences in body composition was observed within the males across the exposure groups.In conclusion, maternal vaping without nicotine may increase risk for elevated body fat in adult life and the development of obesity in female progeny with fetal exposure in utero.Support or Funding InformationWVU Cancer Institute Philip R Dino Innovative Research Grant (IMO), NIHGMS 5U54GM104942‐03 (PDC)

Maternal antibiotic use and vaginal infections in the third trimester of pregnancy and the risk of obesity in preschool children.

SummaryBackground/objectivesSeveral exposures during pregnancy are associated with offspring body mass index (BMI). The objective of this study was to evaluate whether third trimester antibiotic use and vaginal infections are associated with BMI in preschool children.Subjects/methodsThe study population included singletons from the NINFEA birth cohort with available anthropometric measurements at the age of 4 (3151 born with vaginal and 1111 born with caesarean delivery). Self‐reported use of antibiotics and the presence of vaginal infection in the third trimester were analysed in association with the child's BMI, classified into three categories: thinness, normal and overweight/obesity, using both the International Obesity Task Force (IOTF) and the World Health Organization (WHO) recommended cut‐offs.ResultsMaternal vaginal infections in the third trimester of pregnancy were associated with higher relative risk ratios (RRR) for overweight/obesity at age of four in children delivered vaginally: 1.92 (95% confidence interval [CI]: 1.37 to 2.70). This association appeared stronger for children born to women with pre‐pregnancy BMI >25 kg/m2 (RRR: 4.78; 95% CI 2.45 to 9.35), and was robust when different obesity cut‐offs were used. The results regarding third trimester antibiotic use in vaginal deliveries were less conclusive (RRRs for overweight/obesity: 1.43 (0.92 to 2.21) and 1.11 (0.57 to 2.20), for the IOTF and WHO cut‐offs, respectively). Third trimester vaginal infections were not associated with BMI in children delivered by caesarean section.ConclusionsMaternal third trimester vaginal infections are associated with an increased overweight/obesity risk in children born by vaginal delivery, and especially in children of mothers with pre‐pregnancy overweight/obesity.

Adverse pregnancy outcomes on the risk of overweight offspring: a population-based retrospective study in Xiamen, China

The growth trajectory of Chinese preschoolers still remains unclear. Our objective was to determine whether there was an association between adverse pregnancy outcomes and overweight offspring. We analyzed population-based retrospective cohort data from the Medical Birth Registry of Xiamen, which comprised 33,157 children examined from 1 to 6 years of age. Longitudinal analyses were used to evaluate the growth trajectories of offspring body mass index (BMI). Multivariate logistic regression was used to assess the effects of two adverse pregnancy outcomes, gestational diabetes mellitus (GDM) and being large-for-gestational age (LGA), on childhood overweight. Offspring of mothers with GDM and LGA has a higher annual BMI z-score from 1 to 6 years of age (all P < 0.05). But, a higher annual BMI z-score was only observed in children aged 1–5 years in models 1–3. Overall BMI z-score of offspring aged 1–6 who were born to mothers with GDM and LGA were also higher in models 1–3 (all P < 0.05). Additionally, offspring of mothers with GDM and LGA had a higher risk for overweight in model 1, from 1 to 6 years of age (odds ratio (OR), 1.814; 95% confidence interval (CI), 1.657–1.985; P < 0.0001). However, this association was attenuated after adjusting for maternal pre-pregnancy BMI (OR, 1.270; 95% CI, 0.961–1.679; P = 0.0930). Offspring of mothers with GDM and LGA had a higher BMI z-score and increased risk for overweight. Indeed, intrauterine exposure to maternal GDM and LGA could bias offspring to overweight, whereas maternal pre-pregnancy BMI may play a key role in offspring overweight for children born to mothers with GDM and LGA.

Parental Multisite Chronic Pain and the Risk of Adult Offspring Developing Additional Chronic Pain Sites: Family-Linkage Data From the Norwegian HUNT Study

We investigated if parental multisite chronic pain increases the risk of adult offspring developing additional chronic pain sites, and if offspring body mass index (BMI) and leisure time physical activity modify this association. We used longitudinal data on 7,654 offspring linked with their parents who participated in the population-based HUNT Study (Norway) in 1995 to 1997 and 2006 to 2008. Logistic regression was used to estimate odds ratios (ORs) with 95% confidence interval (CI). One-third of offspring (n = 2,573) developed additional chronic pain sites. Having both parents with 1–2 chronic pain sites increased the risk of developing additional pain sites compared to having parents free of chronic pain (OR = 1.33; 95% CI 1.05–1.68), with larger effects observed when both parents had ≥3 chronic pain sites (OR = 1.46; 95% CI 1.17–1.82). These associations were largely driven by maternal pain, that is, there was no association between paternal chronic pain and risk of additional pain sites in offspring. The parent-offspring transfer of additional pain sites (when both parents had ≥3 pain sites) strengthened when offspring were obese (OR = 2.56; 95% CI 1.75–3.75) or physically inactive (OR = 1.73; 95% CI 1.33–2.27). In conclusion, parental multisite chronic pain increases the risk of offspring developing additional chronic pain sites, particularly those with obesity or inactivity. PerspectiveThis longitudinal analysis investigated the parent-offspring transmission of multisite chronic pain, and whether lifestyle behaviors in offspring modify this association. The findings suggest that having parents with multisite chronic pain increases the risk of offspring developing additional chronic pain sites, particularly if offspring are obese or inactive.

Effect of Maternal Nonalcoholic Fatty Liver Disease and Dietary Choline Status on Body Mass and Lipid Profile in Rat Offspring

AbstractBoth maternal metabolic status and nutrition during pregnancy and lactation may have a programming effect on offspring metabolism. The aim of this study was to examine the role of the dietary choline supply during pregnancy and lactation in rat dams suffering from nonalcoholic fatty liver disease (NAFLD) on body weight and plasma lipid profile of the progeny.The research protocol was approved by the local ethics committee. The study groups included the offspring of 1. healthy dams receiving choline during pregnancy and lactation (the control group); 2. NAFLD dams receiving choline during pregnancy and lactation (NN); 3. NAFLD dams receiving choline during pregnancy and a choline-deficient diet during lactation (ND); 4. NAFLD dams receiving a choline-deficient diet during pregnancy and a supply of choline during lactation (DN); and 5. NAFLD dams receiving a choline-deficient diet during both pregnancy and lactation (DD). Body mass and plasma lipid profile were assessed in male and female rats from each group on day 3 (3d), day 24 (24d), and day 90 (90d).Body mass was significantly lower in the male offspring of the DD and DN groups than in the control group. Differences were observed at all times (3d: p = 0.0023; 24d: p &lt; 0.0001; 90d: p &lt; 0.0001). Moreover, body mass was significantly higher in the male offspring of the control group than in any other group. In the female progeny, body mass was higher in the control group than in the ND (24d: p &lt; 0.0001; 90d: p = 0.0067) or NN (24d: p = 0.0058) groups.Total plasma cholesterol concentration was higher in the 90d males of the control group than in the DD group (p = 0.0163) and in the 24d females of the NN group than in the ND group (p = 0.0495). In the 3d animals, LDL was higher (p = 0.0083) but HDL was lower (p = 0.0196) in male rats of the DD and DN groups than in the NN and ND groups. Neither age nor sex affected LDL levels. The plasma levels of triglycerides were not affected by the dietary regimen, sex, or age of the animals.Maternal NAFLD and dietary choline status during pregnancy and lactation affect body mass and lipid profile in rat offspring, and the effects of maternal programming are more pronounced in male offspring than in female.The project was financed by the National Science Centre, Poland (2016/21/D/NZ9/00360).

Effects of Aerobic Exercise during Pregnancy on Neurobehavioral Performances and Serum Levels of GDNF in Adult Male Mice Offspring

Clinical evidence indicates that physical activity during pregnancy may modulate the brain development and improve the neurobehavioral functions of the offspring. Nevertheless, the mechanisms by which exercise during pregnancy may cause such changes are not fully understood. Our study, therefore, aimed to investigate the effects of aerobic exercise (AX) during pregnancy on neurobehavioral functions of adult male mice offspring with emphasis on serum levels of glial cell line-derived neurotrophic factor (GDNF). After pregnancy stabilization, pregnant mice were divided into exercise and control groups. The exercise group performed moderate-intensity AX on a treadmill during pregnancy. The cognitive function, motor coordination, forelimb grip strength, and pain tolerability of adult male offspring were evaluated using the novel object recognition task (NORT), Morris water maze (MWM), raised-beam task, grip strength, and hot-plate test (HPT). The serum levels of GDNF were also measured using the ELISA technique. Results showed that maternal moderate forced exercise improved the cognitive function and motor coordination and also increased pain tolerability in the offspring. It was also observed that AX during pregnancy elevated the GDNF serum level in the offspring. However, AX during pregnancy exerted no significant effects on the body mass and number of offspring, as well as on the forelimb grip strength. Our findings showed that moderate-intensity AX could improve the neurobehavioral functions in adult offspring due, in particular, to increased serum levels of GDNF.

Low food abundance prior to breeding results in female-biased sex allocation in Tengmalm’s Owl (Aegolius funerus)

Parents can enhance their fitness by favouring that sex whose reproductive value is expected to be highest. In species in which females are the larger sex with potentially greater fitness returns, one can assume that parents should bias their investment toward daughters to increase their daughters’ reproductive value (i.e. age-specific expectation of all present and future offspring) and, thereby, indirectly increase their own inclusive fitness. In the study reported here, we investigated sex allocation in Tengmalm’s Owl (Aegolius funereus), a bird species with a pronounced female-biased sexual size dimorphism in which females are larger than the males. Assuming that parental investment would have the greatest effect on the fitness of larger daughters, we hypothesized that daughters should be favoured in good conditions and sons in poor conditions. Our study was conducted in the Czech Republic over seven breeding seasons (2006–2012). In total, 205 nestlings from 52 nests were sexed. The mean nestling sex ratio, 48.5 ± 4.6% (± standard error), did not depart from parity, and we did not identify any variable to be related to it. However, we did find that at fledging (1) the body mass of female offspring was approximately 8% heavier than that of male offspring, and (2) surprisingly, the body mass of female offspring tended to increase with decreasing prey abundance in the autumn, i.e. prior to breeding. One possible explanation of this “carry-over effect” is that parents increased their investment toward daughters to maximize their daughters’ survival and reproductive value in a poor environment. This explanation could be supported by the sex-specific effect of the adult’s condition on reproductive success. Whereas the number of fledglings tended to increase with increasing age of the mother, it also increased with decreasing wing length of the father. These results indicate that in the Tengmalm’s Owl large body size may be mainly important for female reproduction, while male reproductive success is independent of body size or is even associated with small body size. To the best of our knowledge, our study is the first to have found such a positive, relatively long-lasting, sex-specific carry-over effect of pre-breeding prey abundance on the condition of female offspring in a bird of prey species.

Maternal age at menarche and offspring body mass index in childhood

BackgroundEarlier age of menarche has been associated with an increased risk of chronic diseases during adulthood, but whether early menarche has intergenerational effect is not clear.MethodsIn this population-based cross-sectional study, we recruited children from 26 primary schools using cluster random probability sampling in Shanghai, China, in 2014. We used multiple linear regression models to estimate the adjusted associations of maternal age of menarche (MAM) with offspring body mass index (BMI). We also used the mediation analysis to examine the contribution of maternal BMI and gestational diabetes to offspring BMI.ResultsA total of 17,571 children aged 6–13 years were enrolled, of whom 16,373 had their weight and height measured. Earlier MAM was associated with higher child BMI in boys (− 0.05 z-score per year older MAM, 95% CI − 0.08 to − 0.02) and in girls (− 0.05 z-score per year older MAM, 95% CI − 0.07 to − 0.02). Maternal BMI positively mediated the association of MAM with offspring BMI in both sexes, with mediation effects of 37.7 and 19.4% for boys and girls, respectively.ConclusionEarly maternal menarche was associated with greater offspring BMI. This study provides evidence for the intergenerational effect in the development of BMI in offspring.

The more you get, the more you give: Positive cascading effects shape the evolutionary potential of prenatal maternal investment.

Maternal effects are prevalent in nature and significantly contribute to variation in phenotypic trait expression. However, little attention has been paid to the factors shaping variation in the traits mediating these effects (maternal effectors). Specific maternal effectors are often not identified, and typically they are assumed to be inherited in an additive genetic and autosomal manner. Given that these effectors can cause long‐lasting effects on offspring phenotype, it is likely that they may also affect themselves in the next generation. Although the existence of such cascading maternal effects has been discussed and modeled, empirical examples of such effects are rare, let alone quantitative estimates of their strength and evolutionary consequences. Here, we demonstrate that the investment a mother makes in her eggs positively affects the egg investment of her daughters. Through reciprocally crossing artificially selected lines for divergent prenatal maternal investment in Japanese quail (Coturnix japonica), we demonstrate that the size of eggs daughters lay resembles the egg size of their maternal line significantly more than that of their paternal line, highlighting that egg size is in part maternally inherited. Correspondingly, we find that variation in the daughters' egg size is in part determined by maternal identity, in addition to substantial additive genetic effects. Furthermore, this maternal variance in offspring egg size is fully explained by maternal egg size, demonstrating the presence of a positive cascading effect of maternal egg size on offspring egg size. Finally, we use an evolutionary model to quantify the consequences of covariance between cascading maternal and additive genetic effects for both maternal effector and offspring body mass evolution. Our study demonstrates that by amplifying the amount of variation available for selection to act on, positive cascading maternal effects can significantly enhance the evolutionary potential of maternal effectors and the offspring traits that they affect.

Gestational diabetes mellitus, pre-gestational BMI and offspring BMI z-score during infancy and childhood: 2004 Pelotas Birth Cohort

ObjectiveGestational diabetes mellitus (GDM) affects a significant number of women. Evidence regarding the association between GDM and offspring body mass index (BMI) is unclear due to small samples and lack...

Exploring the role of genetic confounding in the association between maternal and offspring body mass index: evidence from three birth cohorts.

BackgroundMaternal pre-pregnancy body mass index (BMI) is positively associated with offspring birth weight (BW) and BMI in childhood and adulthood. Each of these associations could be due to causal intrauterine effects, or confounding (genetic or environmental), or some combination of these. Here we estimate the extent to which the association between maternal BMI and offspring body size is explained by offspring genotype, as a first step towards establishing the importance of genetic confounding.MethodsWe examined the associations of maternal pre-pregnancy BMI with offspring BW and BMI at 1, 5, 10 and 15 years, in three European birth cohorts (n ≤11 498). Bivariate Genomic-relatedness-based Restricted Maximum Likelihood implemented in the GCTA software (GCTA-GREML) was used to estimate the extent to which phenotypic covariance was explained by offspring genotype as captured by common imputed single nucleotide polymorphisms (SNPs). We merged individual participant data from all cohorts, enabling calculation of pooled estimates.ResultsPhenotypic covariance (equivalent here to Pearson’s correlation coefficient) between maternal BMI and offspring phenotype was 0.15 [95% confidence interval (CI): 0.13, 0.17] for offspring BW, increasing to 0.29 (95% CI: 0.26, 0.31) for offspring 15 year BMI. Covariance explained by offspring genotype was negligible for BW [–0.04 (95% CI: –0.09, 0.01)], but increased to 0.12 (95% CI: 0.04, 0.21) at 15 years, which is equivalent to 43% (95% CI: 15%, 72%) of the phenotypic covariance. Sensitivity analyses using weight, BMI and ponderal index as the offspring phenotype at all ages showed similar results.ConclusionsOffspring genotype explains a substantial fraction of the covariance between maternal BMI and offspring adolescent BMI. This is consistent with a potentially important role for genetic confounding as a driver of the maternal BMI–offspring BMI association.

Photoresponsiveness affects life history traits but not oxidative status in a seasonal rodent

BackgroundShortening photoperiod triggers seasonal adjustments like cessation of reproduction, molting and heterothermy. However there is a considerable among-individual variation in photoresponsiveness within one population. Although seasonal adjustments are considered beneficial to winter survival, and natural selection should favor the individuals responding to changes in photoperiod (responders), the phenotype non-responding to changes in day length is maintained in population. Assuming the same resource availability for both phenotypes which differ in strategy of winter survival, we hypothesized that they should differ in life history traits. To test this we compared reproductive traits of two extreme phenotypes of Siberian hamster Phodopus sungorus – responding and non-responding to seasonal changes in photoperiod. We bred individuals of the same phenotype and measured time to first parturition, time interval between litters, offspring body mass 3, 10 and 18 days after birth and their growth rate. We also analyzed nest-building behavior. Additionally, we estimated the correlation between reproduction, and basal metabolic rate (BMR) and oxidative status in both phenotypes to infer about the effect of reproductive output on future investments in somatic maintenance.ResultsPrior to reproduction responding individuals were smaller than non-responding ones, but this difference disappeared after reproduction. Responding pairs commenced breeding later than non-responding ones but there was no difference in time interval between consecutive litters. Responders delivered smaller offspring than non-responders and more out of responding individuals built the nest during winter than non-responding ones. Reproduction did not affect future investments in somatic maintenance. Phenotypes did not differ in BMR and oxidative status after reproduction. However, concentration of reactive oxygen metabolites (ROM) was highest in responding males, and biological antioxidant potential (BAP) was higher in males of both phenotypes than in females.ConclusionsDelayed breeding in responding Siberian hamsters and high ROM concentration in male responders support our hypothesis that differences in adjustment to winter result in different life history characteristics which may explain coexistence of both phenotypes in a population. We propose that polymorphism in photoresponsiveness may be beneficial in stochastic environment, where environmental conditions differ between winters. We suggest that non-responding phenotype may be particularly beneficial during mild winter, whereas responders would be favored under harsh conditions. Therefore, none of the phenotypes is impaired when compared to the other.

Nest microclimate during incubation affects posthatching development and parental care in wild birds

It is widely accepted that recent increases in environmental temperature have had a causal effect on changing life histories; however, much of the evidence for this is derived from long-term observations, whereas inferences of causation require experimentation. Here, we assess effects of increased environmental temperature during incubation on posthatching development, nestling begging and parental care, and reproductive success in two wild, cavity-nesting songbirds, the Carolina wren and prothonotary warbler. We heated experimental nests only during incubation, which increased nest-cavity temperature by ca. 1 °C. This reduced the length of the incubation and nestling periods, and reduced fledging success in prothonotary warblers, while nestling Carolina wrens had similar fledging success but reduced body condition in response to increased temperature. Increased nest-cavity temperature during incubation also reduced posthatching begging by nestlings generally and parental care within Carolina wrens specifically, suggesting potential mechanisms generating these carry-over effects. Offspring body mass and fledging age are often predictive of post-fledging survival and recruitment. Thus, our results suggest that increasing temperatures may affect fitness in wild populations in species-specific ways, and induce life-history changes including the classic trade-off parents face between the size and number of offspring.