Does maternal weight gain in pregnancy have long-term effects on offspring adiposity? A sibling study in a prospective cohort of 146,894 men from 136,050 families

Late midlife C-reactive protein and interleukin-6 in middle aged danish men in relation to body size history within and across generations

OBJECTIVE

The aim was to estimate the effects of ponderal index at birth and body mass index (BMI) in early adulthood on C-reactive protein (CRP) and interleukin-6 (IL-6) and to quantify the effects through subsequent measures of body size. In a subanalysis, the contributions of maternal BMI to the inflammatory status of offspring were investigated.

METHODS

The study was based on 2,986 Danish males from the Copenhagen Aging and Midlife Biobank. Path analysis was employed to estimate direct and indirect effects.

RESULTS

A 10% higher maternal BMI was associated with 7% higher CRP and 3% higher IL-6 among offspring. A 10% higher ponderal index at birth was associated with 4% lower CRP in late midlife; this effect was only partially mediated by later growth. A 10% higher BMI in early adulthood was associated with 8% higher CRP and 4% higher IL-6 in late midlife. The findings suggest that weight gain in adulthood is associated with low-grade inflammation in late midlife.

CONCLUSIONS

Ponderal index at birth is associated with CRP in later life independently of adult BMI. The findings additionally suggest that preventing weight gain in early adulthood would be beneficial for inflammatory status in later life.

Obesity rates in two generations of Swedish women entering pregnancy, and associated obesity risk among adult daughters

We examined changes in obesity rates in two generations of Swedish women entering pregnancy, and assessed the effects of maternal body mass index (BMI) on the risk of overweight or obesity among adult daughters. This study covered an intergenerational retrospective cohort of 26,561 Swedish mothers and their 26,561 first-born daughters. There was a 4-fold increase in obesity rates, which rose from 3.1% among women entering pregnancy in 1982–1988 to 12.3% among their daughters in 2000–2008 (p < 0.0001) when entering pregnancy. The greater the maternal BMI, the greater the odds of overweight and/or obesity among daughters. Underweight mothers had half the odds of having an overweight or obese daughter in comparison to mothers of normal BMI (p < 0.0001). In contrast, the odds ratio of obese mothers having obese daughters was 3.94 (p < 0.0001). This study showed a strong association between maternal obesity and the risk of obesity among their first-born daughters. In addition, we observed a considerable increase in obesity rates across generations in mother-daughter pairs of Swedish women entering pregnancy. Thus, it is important to have preventative strategies in place to halt the worsening intergenerational cycle of obesity.

Maternal Gestational and Postdelivery Weight Gain and Child Weight

BACKGROUND

Maternal gestational weight gain (GWG) is a risk factor for the development of overweight in her child. It is unknown whether GWG programs the child's health or whether GWG indicates a shared familial lifestyle during childhood. To disentangle these influences, we studied the association of GWG and postdelivery maternal weight change simultaneously with child's weight development.

METHODS

We used data from 3367 children participating in a birth cohort that started in 1996 in the Netherlands. Weight and height were self-reported. GWG was categorized as "inadequate," "adequate," and "excessive." Multivariable regression and mixed models were used to study maternal and child weight changes.

RESULTS

Children of mothers with excessive GWG had a higher BMI z score and overweight prevalence (odds ratio [OR] 1.20; 95% confidence interval [CI], 0.99 to 1.46) throughout childhood. Children of mothers with a high (≥1 kg/year) postdelivery weight gain had a 0.14 (95% CI, -0.08 to 0.36) higher change in BMI z score between age 1 and 14 years than children of mothers with a low (<0.5 kg/year) postdelivery weight gain. Children of mothers with excessive GWG in combination with a high postdelivery weight gain had the highest BMI z score and overweight risk at age 14 years (OR 3.53; 95% CI, 1.70 to 7.33).

CONCLUSIONS

Maternal GWG and postdelivery weight gain contribute to child's weight development up to adolescence independently.

Lifestyle intervention to prevent excessive maternal weight gain: mother and infant follow-up at 12 months postpartum

Background

Excessive gestational weight gain (GWG) is associated with elevated weight retention in mothers and might be related to adiposity of their offspring. Little is known if lifestyle intervention during pregnancy has beneficial effects for mothers and children beyond gestation.

Methods

A cluster-randomized controlled intervention trial was performed with 250 pregnant women in 8 gynaecological practices. Lifestyle intervention was carried out twice with individual counselling sessions on nutrition, physical activity and weight monitoring. Participants in the control group received routine prenatal care and an information leaflet. Follow-up data of women and their offspring were collected one year postpartum (pp) by phone call and/or via e-mail using a structured questionnaire. Maternal weight retention at 12 months pp and weight development of the children in their first year of life was compared between groups using linear regression. The association between energy and macronutrient intake during pregnancy with maternal weight retention and children weight development was also assessed.

Results

The intervention resulted in a trend towards lower mean weight retention 12 months pp (0.2 vs. 0.8 kg), but was not statistically significant (p = 0.321). Among women receiving lifestyle counselling, only 8 % retained more than 5 kg weight while 17 % in the control group retained >5 kg (OR: 0.40 (95 % CI: 0.16, 0.97)). For the whole study cohort, an association between higher GWG and increased 12 month weight retention was found (0.4 kg weight retention per 1 kg increase in GWG, p < 0.001). Weight development of the infants did not differ between groups in the first months after birth. At the 10^th–12^th month weight measurement, infants born to mothers in the intervention group tended towards lower body weights. Both energy intake and macronutrient composition of the diet during pregnancy did not affect maternal weight retention and weight development of the infants.

Conclusions

Lifestyle counselling during pregnancy to avoid GWG had a rather modest effect on maternal pp weight retention and weight development of the infants. However, larger intervention studies and longer follow-up are required to be able to draw definite conclusions.

Trial registration

German Clinical Trials Register DRKS00003801.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-015-0701-2) contains supplementary material, which is available to authorized users.

Gestational weight gain according to Institute of Medicine recommendations in relation to infant size and body composition

BACKGROUND

Intrauterine life may be a critical period for programming childhood obesity; however, there is insufficient knowledge concerning how gestational weight gain (GWG) affects infant fat mass (FM) and fat-free mass (FFM).

OBJECTIVES

The aim of this study was to investigate relationships between GWG according to Institute of Medicine (IOM) recommendations and infant size, FM and FFM. We also investigated if the associations were different for normal-weight and overweight/obese women.

METHODS

This study included 312 healthy Swedish mother-infant pairs. Infant body composition at 1 week of age was assessed using air-displacement plethysmography. Maternal GWG was defined as below, within or above the 2009 IOM recommendations. Multiple regression analyses were used.

RESULTS

Compared with women whose weight gain was within IOM recommendations, women with weight gain below the recommendations had infants that were shorter (-0.7 cm, P = 0.008) when adjusting for confounders. Normal-weight women exceeding IOM recommendations had infants with higher FM (+58 g, P = 0.008) compared with normal-weight women who gained within the recommendations. No corresponding association was observed for overweight/obese women.

CONCLUSIONS

Inadequate GWG was associated with shorter infants, while excessive GWG was associated with greater infant FM for women who were of normal weight before pregnancy.

Maternal obesity during pregnancy and cardiovascular development and disease in the offspring

Maternal obesity during pregnancy is an important public health problem in Western countries. Currently, obesity prevalence rates in pregnant women are estimated to be as high as 30 %. In addition, approximately 40 % of women gain an excessive amount of weight during pregnancy in Western countries. An accumulating body of evidence suggests a long-term impact of maternal obesity and excessive weight gain during pregnancy on adiposity, cardiovascular and metabolic related health outcomes in the offspring in fetal life, childhood and adulthood. In this review, we discuss results from recent studies, potential underlying mechanisms and challenges for future epidemiological studies.

Gestational weight gain and the risk of offspring obesity at 10 and 16 years: a prospective cohort study in low-income women

OBJECTIVE

To study the association between gestational weight gain (GWG) and offspring obesity risk at ages chosen to approximate prepuberty (10 years) and postpuberty (16 years).

DESIGN

Prospective pregnancy cohort.

SETTING

Pittsburgh, PA, USA.

SAMPLE

Low-income pregnant women (n = 514) receiving prenatal care at an obstetric residency clinic and their singleton offspring.

METHODS

Gestational weight gain was classified based on maternal GWG-for-gestational-age Z-score charts and was modelled using flexible spline terms in modified multivariable Poisson regression models.

MAIN OUTCOME MEASURES

Obesity at 10 or 16 years, defined as body mass index (BMI) Z-scores ≥95th centile of the 2000 CDC references, based on measured height and weight.

RESULTS

The prevalence of offspring obesity was 20% at 10 years and 22% at 16 years. In the overall sample, the risk of offspring obesity at 10 and 16 years increased when GWG exceeded a GWG Z-score of 0 SD (equivalent to 30 kg at 40 weeks); but for gains below a Z-score of 0 SD there was no relationship with child obesity risk. The association between GWG and offspring obesity varied by prepregnancy BMI. Among mothers with a pregravid BMI <25 kg/m(2) , the risk of offspring obesity increased when GWG Z-score exceeded 0 SD, yet among overweight women (BMI ≥25 kg/m(2) ), there was no association between GWG Z-scores and offspring obesity risk.

CONCLUSIONS

Among lean women, higher GWG may have lasting effects on offspring obesity risk.

Macrosomic Neonates Carry Increased Risk of Dental Caries in Early Childhood: Findings from a Cohort Study, the Okinawa Child Health Study, Japan

BACKGROUND

Although many studies have discussed health risks in neonates with a low birth weight, few studies have focused on the risks in neonates with a high birth weight. The objective of this study was to determine whether differences in the incidence of dental caries in early childhood are associated with birth weight status.

METHODS

A total of 117,175 children born in Okinawa Prefecture, Japan from 1997 to 2007 were included in this study. Medical professionals collected information about birth records, growth and development, parental child-rearing practices and dental health at 3 months, 18 months and 3 years of age. The risk of dental caries among neonates with macrosomia (birth weight ≥4000 g) was compared with that among neonates with normal weight (2500-3999 g). Sensitivity analyses included 'large for gestational age' (LGA, birth weight above the 90th percentile for gestational age), which was relative to 'appropriate for gestational age' (birth weight between 10th and 90th percentiles). Relative risks and relative risk increases were estimated by multivariate Poisson regression.

RESULTS

At 3 years of age, the relative risk increases for dental caries after adjusting for confounding factors were 19% [95% confidence interval (CI), 11%-28%, P < 0.001] for macrosomic neonates and 12% (95% CI, 9%-16%, P < 0.001) for LGA neonates.

CONCLUSION

Macrosomia and LGA were associated with an increased risk of dental caries in early childhood. Particular attention should be paid to abnormally large neonates.

Maternal pre-pregnancy BMI and gestational weight gain, offspring DNA methylation and later offspring adiposity: findings from the Avon Longitudinal Study of Parents and Children

Background: Evidence suggests that in utero exposure to undernutrition and overnutrition might affect adiposity in later life. Epigenetic modification is suggested as a plausible mediating mechanism.

Methods: We used multivariable linear regression and a negative control design to examine offspring epigenome-wide DNA methylation in relation to maternal and offspring adiposity in 1018 participants.

Results: Compared with neonatal offspring of normal weight mothers, 28 and 1621 CpG sites were differentially methylated in offspring of obese and underweight mothers, respectively [false discovert rate (FDR)-corrected P-value < 0.05), with no overlap in the sites that maternal obesity and underweight relate to. A positive association, where higher methylation is associated with a body mass index (BMI) outside the normal range, was seen at 78.6% of the sites associated with obesity and 87.9% of the sites associated with underweight. Associations of maternal obesity with offspring methylation were stronger than associations of paternal obesity, supporting an intrauterine mechanism. There were no consistent associations of gestational weight gain with offspring DNA methylation. In general, sites that were hypermethylated in association with maternal obesity or hypomethylated in association with maternal underweight tended to be positively associated with offspring adiposity, and sites hypomethylated in association with maternal obesity or hypermethylated in association with maternal underweight tended to be inversely associated with offspring adiposity.

Conclusions: Our data suggest that both maternal obesity and, to a larger degree, underweight affect the neonatal epigenome via an intrauterine mechanism, but weight gain during pregnancy has little effect. We found some evidence that associations of maternal underweight with lower offspring adiposity and maternal obesity with greater offspring adiposity may be mediated via increased DNA methylation.

Time to subsequent live birth according to mode of delivery in the first birth

OBJECTIVE

To estimate the rate and time to next live birth by mode of delivery.

DESIGN

Hospital-based cohort.

SETTING

Aarhus University Hospital (AUH), Denmark.

POPULATION

All pregnant women attending AUH were invited to enroll in the Aarhus Birth Cohort (ABC) study between 1989 and 2010 (n = 91,625).

METHODS

Women were followed from their first live birth until the subsequent live birth or until censoring due to study end using Cox regression models.

MAIN OUTCOME MEASURES

Rate and time to subsequent live birth according to mode of delivery.

RESULTS

46,162 index live births were identified, of which 22,462 (49%) had a subsequent live birth. Women with any type of caesarean had a 6% reduction in the rate of subsequent live birth (HR 0.94, 95% CI 0.89, 0.98), which remained unchanged in the analysis by type (emergency, HR 0.95, 95% CI 0.89, 1.02; elective, HR 0.91, 95% CI 0.85, 0.98) compared with women who had a spontaneous vaginal delivery (SVD). Operative vaginal delivery was associated with an 8% reduction in subsequent live birth rates (HR 0.92, 95% CI 0.86, 0.98) and vaginal delivery complicated by shoulder dystocia with a 19% reduction compared with SVD. Median time to next birth in days was shortest in women with a first caesarean (994 days, 95% CI 973, 1026) and longest in women with a vaginal delivery complicated by shoulder dystocia (1065 days, 95% CI 994, 1191). In women with planned pregnancies, the shortest median time to second birth was in women with breech vaginal deliveries (859 days, 95% CI 737, 1089) and the longest in women with vaginal deliveries complicated by shoulder dystocia (1193 days, 95% CI 1028, 1430).

CONCLUSION

The impact of mode of delivery on subsequent rate and time to next birth was minimal in this study. The greatest reduction was among women with assisted vaginal delivery complicated by shoulder dystocia. This study is strengthened by data on pregnancy planning as well as information on complications of pregnancy, delivery and neonatal morbidities, all of which may influence a woman's decision on subsequent birth.

Gestational weight gain and obesity, adiposity and body size in African-American and Dominican children in the Bronx and Northern Manhattan

Gestational weight gain (GWG) is potentially modifiable and is associated with infant size and body composition; however, long-term effects on childhood obesity have not been reported among multi-ethnic urban populations. We examined the association between GWG and child anthropometric measures and body composition at 7 years [waist circumference (WC), body mass index z-score (BMIZ), obesity (BMIZ ≥95%ile) and bioelectrical impedance analysis estimates of percentage body fat (%fat)] in African-American and Dominican dyads (n = 323) in the Columbia Center for Children's Environmental Health prospective birth cohort study from 1998 to 2013. Linear and logistic regression evaluated associations between excessive GWG [>Institute of Medicine (IOM) 2009 guidelines] and outcomes, adjusting for pre-pregnancy BMI and covariates. Pre-pregnancy BMI (mean ± standard deviation, all such values) and total GWG were 25.8 ± 6.2 kg m(-2) (45% overweight/obese) and 16.4 ± 7.9 kg (64% > IOM guidelines), respectively. Excessive GWG was associated with higher BMIZ {0.44 [95% confidence interval (CI): 0.2, 0.7], P < 0.001}, WC [β: 2.9 cm (95% CI: 1.1, 4.6), P = 0.002], %fat at 7 years [β: 2.2% (95% CI: 1.0, 3.5), P = 0.001)] and obesity [odds ratio: 2.93 (95% CI: 1.5, 5.8), P = 0.002]. Pre-pregnancy BMI was positively associated with child size, adiposity and obesity (all P < 0.05). Excessive GWG was highly prevalent and was associated with child obesity, greater percentage body fat and abdominal adiposity. Strategies to support healthy GWG are warranted to promote healthy growth and prevent childhood obesity.

Differences in gestational weight gain between pregnancies before and after maternal bariatric surgery correlate with differences in birth weight but not with scores on the body mass index in early childhood

BACKGROUND

Large maternal gestational weight gain (GWG) is associated with increased birth weight and increased risk of obesity in offspring, but these associations may be confounded by genetic and environmental factors. The aim was to investigate the effects of differences in GWG in all three trimesters on differences in birth weight and in body mass index (BMI) scores at 4 and 6 years of age, within siblings born before and after bariatric surgery.

METHOD

Women with at least one child born before and one after bariatric surgery were identified in national Swedish registers. Series of weight (and height) measurements were collected from antenatal medical records, with data on the nearest pregnancies before and after bariatric surgery.

RESULTS

The age-adjusted means of pre- and post-operative GWG of 124 women were 11.3 (standard deviation [SD] 7.2) and 8.3 (SD 6.4) kg, respectively (P = 0.01). Adjusted fixed effects regression models showed positive associations of differences in mean total GWG with differences in siblings' birth weight, 0.023 kg per 1-kg greater weight gain (95% confidence interval [CI]: 0.014-0.069) and for second trimester 0.53 kg for each 1-kg greater weight per week (95% CI: 0.32-1.61), whereas no associations were found with BMI in pre-school age.

CONCLUSION

This study showed positive associations between differences in total and second trimester maternal GWG and differences in children's birth weight, but no association with BMI scores in pre-school age. Maternal genetic, social and lifestyle factors fixed from one pregnancy to the next were taken into account in the analyses by the study design.

Approaches for drawing causal inferences from epidemiological birth cohorts: a review

Large-scale population-based birth cohorts, which recruit women during pregnancy or at birth and follow up their offspring through infancy and into childhood and adolescence, provide the opportunity to monitor and model early life exposures in relation to developmental characteristics and later life outcomes. However, due to confounding and other limitations, identification of causal risk factors has proved challenging and published findings are often not reproducible. A suite of methods has been developed in recent years to minimise problems afflicting observational epidemiology, to strengthen causal inference and to provide greater insights into modifiable intra-uterine and early life risk factors. The aim of this review is to describe these causal inference methods and to suggest how they may be applied in the context of birth cohorts and extended along with the development of birth cohort consortia and expansion of "omic" technologies.

Impact of maternal obesity on perinatal and childhood outcomes

Maternal obesity is of major consequence, affecting every aspect of maternity care including both short- and long-term effects on the health of the offspring. Obese mothers are at a higher risk of developing gestational diabetes and pre-eclampsia, potentially exposing the foetus to an adverse intrauterine environment. Maternal obesity is linked to foetal macrosomia, resulting in increased neonatal and maternal morbidity. Foetal macrosomia is a result of a change in body composition in the neonate with an increase in both percentage fat and fat mass. Maternal obesity and gestational weight gain are associated with childhood obesity, and this effect extends into adulthood. Childhood obesity in turn increases chances of later life obesity, thus type 2 diabetes, and cardiovascular disease in the offspring. Further clinical trials of lifestyle and, potentially, pharmacological interventions in obese pregnant women are required to determine whether short- and long-term adverse effects for the mother and child can be reduced.

Childhood consequences of maternal obesity and excessive weight gain during pregnancy

Obesity is a major public health concern. In western countries, the prevalence of obesity in pregnant women has strongly increased, with reported prevalence rates reaching 30%. Also, up to 40% of women gain an excessive amount of weight during pregnancy. Recent observational studies and meta-analyses strongly suggest long-term impact of maternal obesity and excessive weight gain during pregnancy on adiposity, cardiovascular and respiratory related health outcomes in their children. These observations suggest that maternal adiposity during pregnancy may program common health problems in the offspring. Currently, it remains unclear whether the observed associations are causal, or just reflect confounding by family-based sociodemographic or lifestyle-related factors. Parent-offspring studies, sibling comparison studies, Mendelian randomization studies and randomized trials can help to explore the causality and underlying mechanisms. Also, the potential for prevention of common diseases in future generations by reducing maternal obesity and excessive weight gain during pregnancy needs to be explored.

Maternal weight gain in different periods of pregnancy and childhood cardio-metabolic outcomes. The Generation R Study

BACKGROUND

Excessive gestational weight gain seems to be associated with offspring cardio-metabolic risk factors. Little is known about the critical periods of gestational weight gain. We examined the associations of maternal weight gain in different periods of pregnancy with childhood cardio-metabolic risk factors.

METHODS

In a population-based prospective cohort study from early pregnancy onwards among 5908 mothers and their children, we obtained maternal prepregnancy weight and weight in early, mid and late pregnancy. At the age of 6 years (median: 72.6 months; 95% range: 67.9, 95.8), we measured childhood body mass index (BMI), total body and abdominal fat distribution, blood pressure and blood levels of lipids, insulin and c-peptide.

RESULTS

Overall, the associations of maternal prepregnancy weight with childhood outcomes were stronger than the associations of maternal gestational weight gain. Independent from maternal prepregnancy weight and weight gain in other periods, higher weight gain in early pregnancy was associated with higher childhood BMI, total fat mass, android/gynoid fat mass ratio, abdominal subcutaneous fat mass and systolic blood pressure (P-values<0.05). Independent associations of maternal weight gain in early pregnancy with childhood abdominal preperitoneal fat mass, insulin and c-peptide were of borderline significance. Higher weight gain in mid pregnancy was independently associated with higher childhood BMI, total and abdominal subcutaneous fat mass and systolic blood pressure (P-values<0.05). The associations for childhood cardio-metabolic outcomes attenuated after adjustment for childhood BMI. Weight gain in late pregnancy was not associated with childhood outcomes. Higher weight gain in early, but not in mid or late pregnancy, was associated with increased risks of childhood overweight and clustering of cardio-metabolic risk factors (odds ratio (OR) 1.19 (95% confidence interval (CI): 1.10, 1.29) and OR 1.20 (95% CI: 1.07, 1.35) per standard deviation increase in early gestational weight gain, respectively).

CONCLUSIONS

Higher weight gain in early pregnancy is associated with an adverse cardio-metabolic profile in offspring. This association is largely mediated by childhood adiposity.

Maternal weight gain in pregnancy and risk of obesity among offspring: a systematic review

OBJECTIVES

To systematically review the evidence from prospective and retrospective cohort studies on the association between gestational weight gain (GWG) and offspring's body weight.

METHODS

Electronic databases PubMed, Web of Science, CINAHL, and Academic Search Premiere were searched from inception through March 18, 2013. Included studies (n = 23) were English articles that examined the independent associations of GWG with body mass index (BMI) and/or overweight status in the offspring aged 2 to 18.9 years. Two authors independently extracted the data and assessed methodological quality of the included studies.

RESULTS

Evidence from cohort studies supports that total GWG and exceeding the Institute of Medicine maternal weight gain recommendation were associated with higher BMI z-score and elevated risk of overweight or obesity in offspring. The evidence of high rate of GWG during early- and mid-pregnancy is suggestive. Additionally, the evidence on inadequate GWG and net GWG in relation to body weight outcomes in offspring is insufficient to draw conclusions.

CONCLUSIONS

These findings suggest that GWG is a potential risk factor for childhood obesity. However, findings should be interpreted with caution due to measurement issues of GWG and potential confounding effects of shared familial characteristics (i.e., genetics and maternal and child's lifestyle factors).

Maternal obesity and diabetes may cause DNA methylation alteration in the spermatozoa of offspring in mice

BACKGROUND

The adverse effects on offspring of diabetic and/or obese mothers can be passed to the next generation. However, the mechanisms behind this are still unclear. Epigenetics may play a key role during this process.

METHODS

To confirm the hypothesis, we investigated the DNA methylation of several imprinted genes in spermatozoa of offspring from diabetic and/or obese mothers utilizing streptozotocin (STZ)- and high-fat-diet (HFD)-induced mouse models.

RESULTS

We found that the DNA methylation of Peg3 was significantly increased in spermatozoa of offspring of obese mothers compared to that in spermatozoa of offspring of normal mothers. The DNA methylation of H19 was significantly higher in spermatozoa of offspring of diabetic mothers than that in spermatozoa of offspring of non-diabetic mothers.

CONCLUSIONS

These results indicate that pre-gestational diabetes and/or obesity can alter DNA methylation in offspring spermatozoa.

Gestational weight gain in relation to offspring obesity over the life course: a systematic review and bias-adjusted meta-analysis

Gestational weight gain (GWG) is considered one of the risk factors for future obesity in the offspring. However, the direction and strength of this association at different periods of offspring life is relatively unknown. This study investigates whether excess or inadequate maternal GWG during pregnancy influences the risk of offspring obesity at different stages in life. A systematic review of published articles was undertaken after a comprehensive search of different databases, and extracted data were meta-analysed. To quantify offspring obesity estimates in relation to GWG, we stratified obesity estimates within three life stages of the offspring age: <5 years, 5 to <18 years and 18+ years. Our meta-analysis showed that, compared with offspring of women with adequate GWG, offspring of women who gained inadequate gestational weight were at a decreased risk of obesity (relative risk [RR]: 0.86; 95% confidence interval [CI]: 0.78-0.94), and offspring of women who gained excess weight were at an increased risk of obesity (RR: 1.40; 95% CI: 1.23-1.59). These relationships were similar after stratification by life stage. Findings of this study therefore suggest that excess GWG does influence offspring obesity over the short- and long-term, and should therefore be avoided.

Maternal genetic variation accounts in part for the associations of maternal size during pregnancy with offspring cardiometabolic risk in adulthood

BACKGROUND

Maternal pre-pregnancy body-mass index (ppBMI) and gestational weight gain (GWG) are associated with cardiometabolic risk (CMR) traits in the offspring. The extent to which maternal genetic variation accounts for these associations is unknown.

METHODS/RESULTS

In 1249 mother-offspring pairs recruited from the Jerusalem Perinatal Study, we used archival data to characterize ppBMI and GWG and follow-up data from offspring to assess CMR, including body mass index (BMI), waist circumference, glucose, insulin, blood pressure, and lipid levels, at an average age of 32. Maternal genetic risk scores (GRS) were created using a subset of SNPs most predictive of ppBMI, GWG, and each CMR trait, selected among 1384 single-nucleotide polymorphisms (SNPs) characterizing variation in 170 candidate genes potentially related to fetal development and/or metabolic risk. We fit linear regression models to examine the associations of ppBMI and GWG with CMR traits with and without adjustment for GRS. Compared to unadjusted models, the coefficient for the association of a one-standard-deviation (SD) difference in GWG and offspring BMI decreased by 41% (95%CI -81%, -11%) from 0.847 to 0.503 and the coefficient for a 1SD difference in GWG and WC decreased by 63% (95%CI -318%, -11%) from 1.196 to 0.443. For other traits, there were no statistically significant changes in the coefficients for GWG with adjustment for GRS. None of the associations of ppBMI with CMR traits were significantly altered by adjustment for GRS.

CONCLUSIONS

Maternal genetic variation may account in part for associations of GWG with offspring BMI and WC in young adults.

Pregnancy and post-delivery maternal weight changes and overweight in preschool children

OBJECTIVES

High maternal weight before and during pregnancy contributes to child obesity. To assess the additional role of weight change after delivery, we examined associations between pre- and post-pregnancy weight changes and preschooler overweight.

METHODS

SAMPLE

4359 children from the Children and Young Adults of the 1979 National Longitudinal Survey of Youth (NLSY) born to 2816 NLSY mothers between 1979 and 2006 and followed to age 4-5years old.

EXPOSURES

gestational weight gain (GWG) and post-delivery maternal weight change (PDWC).

OUTCOME

child overweight (body mass index (BMI) ≥85th percentile).

RESULTS

Adjusted models suggested that both increased GWG (OR: 1.08 per 5kg GWG, 95% CI: 1.01, 1.16) and excessive GWG (OR: 1.29 versus adequate GWG, 95% CI: 1.06, 1.56) were associated with preschooler overweight. Maternal weight change after delivery was also independently associated with child overweight (OR: 1.12 per 5kg PDWC, 95% CI: 1.04, 1.21). Associations were stronger among children with overweight or obese mothers.

CONCLUSIONS

Increased maternal weight gain both during and after pregnancy predicted overweight in preschool children. Our results suggest that healthy post-pregnancy weight may join normal pre-pregnancy BMI and adequate GWG as a potentially modifiable risk factor for child overweight.

Developmental Origins of Cardiovascular Disease

Although cardiovascular disease has traditionally been viewed as a condition of aging individuals, increasing focus has turned to its developmental origins. Since birthweight has been related to cardiovascular disease risk, research into factors such as gravid conditions that affect fetal growth have grown. Associations between maternal diabetes and childhood obesity from sibling studies suggest a causal role but prospective studies of gestational diabetes remain mixed. Preeclampsia and increased offspring blood pressure has been consistently observed but evidence for other cardiovascular outcomes is lacking. While maternal obesity is associated with childhood obesity, causality remains unclear and paternal obesity should be investigated as an independent risk factor. Environmental chemical exposures in utero, particularly obesogens, are now emerging as another concern, as is conception by infertility treatment. Few studies have investigated subclinical measures of endothelial function or atherosclerosis and more research in these areas may help reveal the underlying pathogenesis.

Maternal and in utero determinants of type 2 diabetes risk in the young

The global prevalence of diabetes mellitus has reached epidemic proportions. In 2010, it was estimated that 6.4 % of the adult population (285 million) have diabetes. In recent years, the incidence of type 2 diabetes (T2D), a condition traditionally associated with aging, has been steadily increasing among younger individuals. It is now a well-established notion that the early-life period is a critical window of development and that influences during this period can "developmentally prime" the metabolic status of the adult. This review discusses the role of maternal and in utero influences on the developmental priming of T2D risk. Both human epidemiological studies and experimental animal models are beginning to demonstrate that early dietary challenges can accelerate the onset of age-associated metabolic disturbances, including insulin resistance, T2D, obesity, hypertension, and cardiovascular disease. These findings show that poor maternal nutrition can prime a prediabetes phenotype, often manifest as insulin resistance, by very early stages of life. Thus, the maternal diet is a critical determinant of premature T2D risk. While the mechanisms that link early nutrition to age-associated metabolic decline are currently unclear, preliminary findings suggest perturbations in a number of processes involved in cellular aging, such as changes in longevity-associated Sirtuin activity, epigenetic regulation of key metabolic genes, and mitochondrial dysfunction. Preliminary studies show that pharmacological interventions in utero and dietary supplementation in early postnatal life may alleviate insulin resistance and reduce T2D risk. However, further studies are warranted to fully understand the relationship between the early environment and long-term effects on metabolism. Such mechanistic insights will facilitate strategic interventions that prevent accelerated metabolic decline and the premature onset of T2D in the current and future generations.

Pregnancy weight gain and childhood body weight: a within-family comparison

BACKGROUND

Excessive pregnancy weight gain is associated with obesity in the offspring, but this relationship may be confounded by genetic and other shared influences. We aimed to examine the association of pregnancy weight gain with body mass index (BMI) in the offspring, using a within-family design to minimize confounding.

METHODS AND FINDINGS

In this population-based cohort study, we matched records of all live births in Arkansas with state-mandated data on childhood BMI collected in public schools (from August 18, 2003 to June 2, 2011). The cohort included 42,133 women who had more than one singleton pregnancy and their 91,045 offspring. We examined how differences in weight gain that occurred during two or more pregnancies for each woman predicted her children's BMI and odds ratio (OR) of being overweight or obese (BMI≥85th percentile) at a mean age of 11.9 years, using a within-family design. For every additional kg of pregnancy weight gain, childhood BMI increased by 0.0220 (95% CI 0.0134-0.0306, p<0.0001) and the OR of overweight/obesity increased by 1.007 (CI 1.003-1.012, p = 0.0008). Variations in pregnancy weight gain accounted for a 0.43 kg/m(2) difference in childhood BMI. After adjustment for birth weight, the association of pregnancy weight gain with childhood BMI was attenuated but remained statistically significant (0.0143 kg/m(2) per kg of pregnancy weight gain, CI 0.0057-0.0229, p = 0.0007).

CONCLUSIONS

High pregnancy weight gain is associated with increased body weight of the offspring in childhood, and this effect is only partially mediated through higher birth weight. Translation of these findings to public health obesity prevention requires additional study. Please see later in the article for the Editors' Summary.

Nutritional programming of insulin resistance: causes and consequences

Strong evidence indicates that adverse prenatal and early postnatal environments have a significant long-term influence on risk factors that result in insulin resistance, type 2 diabetes (T2D), and cardiovascular disease later in life. Here we discuss current knowledge of how maternal and neonatal nutrition influence early growth and the long-term risk of developing insulin resistance in different organs and at the whole-body level. Accumulating evidence supports a role for epigenetic mechanisms underlying this nutritional programming, consisting of heritable changes that regulate gene expression which in turn shapes the phenotype across generations. Deciphering these molecular mechanisms in key tissues and discovering key biological markers may provide valuable insight towards the development of effective intervention strategies.

Socio-cultural, environmental and behavioural determinants of obesity in black South African women

South Africa (SA) is undergoing a rapid epidemiological transition and has the highest prevalence of obesity in sub-Saharan Africa (SSA), with black women being the most affected (obesity prevalence 31.8%). Although genetic factors are important, socio-cultural, environmental and behavioural factors, as well as the influence of socio-economic status, more likely explain the high prevalence of obesity in black SA women. This review examines these determinants in black SA women, and compares them to their white counterparts, black SA men, and where appropriate, to women from SSA. Specifically this review focuses on environmental factors influencing obesity, the influence of urbanisation, as well as the interaction with socio-cultural and socio-economic factors. In addition, the role of maternal and early life factors and cultural aspects relating to body image are discussed. This information can be used to guide public health interventions aimed at reducing obesity in black SA women.

The implications and consequences of maternal obesity on fetal intrauterine growth restriction

CONTEXT

The prevalence of maternal obesity has been increasing dramatically in the recent years (body mass index ≥ 30 kg/m2). Maternal obesity is associated with an unequivocal increase in maternal and fetal complications of pregnancy and more than that, these complications also extend beyond fetal life in childhood and adulthood. Objective. The aim of this study was to evaluate maternal and neonatal complications at birth associated with maternal obesity.

MATERIALS AND METHODS

The study included all women who gave birth between January 1, 2012 and December 31, 2012 at Bucharest University Emergency Hospital. Collected data included information about maternal health (the degree of obesity, associated complications of birth, anemia, and type of birth) and neonatal status (birth weight, gestational age, associated diseases and Apgar score).

RESULTS

A higher incidence of IUGR, as well as an increased frequency of infants who needed intensive care after birth, a higher rate of cesarean surgery and a higher frequency of thromboembolic complications were observed in patients with associated obesity.

CONCLUSIONS

Complications grow both in number and severity with increasing obesity. Diagnosis of the fetuses with IUGR is important for the monitoring and management of the pregnancy associated with obesity and it involves a close collaboration between obstetrician, family physician and neonatologist.

Maternal obesity during pregnancy and premature mortality from cardiovascular event in adult offspring: follow-up of 1 323 275 person years

OBJECTIVES

To determine whether maternal obesity during pregnancy is associated with increased mortality from cardiovascular events in adult offspring.

DESIGN

Record linkage cohort analysis.

SETTING

Birth records from the Aberdeen Maternity and Neonatal databank linked to the General Register of Deaths, Scotland, and the Scottish Morbidity Record systems.

POPULATION

37 709 people with birth records from 1950 to present day.

MAIN OUTCOME MEASURES

Death and hospital admissions for cardiovascular events up to 1 January 2012 in offspring aged 34-61. Maternal body mass index (BMI) was calculated from height and weight measured at the first antenatal visit. The effect of maternal obesity on outcomes in offspring was tested with time to event analysis with Cox proportional hazard regression to compare outcomes in offspring of mothers in underweight, overweight, or obese categories of BMI compared with offspring of women with normal BMI.

RESULTS

All cause mortality was increased in offspring of obese mothers (BMI >30) compared with mothers with normal BMI after adjustment for maternal age at delivery, socioeconomic status, sex of offspring, current age, birth weight, gestation at delivery, and gestation at measurement of BMI (hazard ratio 1.35, 95% confidence interval 1.17 to 1.55). In adjusted models, offspring of obese mothers also had an increased risk of hospital admission for a cardiovascular event (1.29, 1.06 to 1.57) compared with offspring of mothers with normal BMI. The offspring of overweight mothers also had a higher risk of adverse outcomes.

CONCLUSIONS

Maternal obesity is associated with an increased risk of premature death in adult offspring. As one in five women in the United Kingdom is obese at antenatal booking, strategies to optimise weight before pregnancy are urgently required.

Female obesity: short- and long-term consequences on the offspring

The worldwide prevalence of obesity has risen over the past few decades and women are currently more likely than ever to enter pregnancy obese. Pre-pregnancy obesity and excessive gestational weight gain increase miscarriage rates and obstetric and neonatal complications, which result in a lower healthy live birth rate. In addition to its negative consequences for the mother, obesity has been shown to be an important risk factor for chronic illnesses, such as cardiovascular disease, metabolic syndrome and type 2 diabetes in the adolescence and adulthood of the offspring. Moreover, maternal obesity causes psychological problems, physical disabilities and higher healthcare costs. Fetal programming of metabolic function induced by obesity, through physiological and/or epigenetic mechanisms, may have an intergenerational effect and could, thus, perpetuate obesity in the next generation. In order to break this vicious circle and avoid serious short- and long-term negative outcomes for both mothers and fetuses, the prevention and adequate management of obesity and gestational weight gain are essential.

Gestational weight gain in accordance to the IOM/NRC criteria and the risk for childhood overweight: a meta-analysis

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Gestational weight gain is a modifiable risk factor for childhood overweight.

WHAT THIS STUDY ADDS

Exceeding the recommended gestational weight gain increases the risk for childhood overweight by about 30%. Interventions to avoid excessive weight gain are needed.

BACKGROUND

Overweight and obesity in children are thought to be related to prenatal priming. Gestational weight gain (GWG) might be a potential modifiable risk factor for childhood overweight.

OBJECTIVE

To quantify the associations of inadequate and excessive GWG with childhood overweight.

METHODS

The electronic literature search in six databases was complemented by a hand search for relevant articles. Papers were selected and quality was assessed. The effect estimates of the individual studies were pooled using a random-effects model.

RESULTS

The literature search yielded 1492 results in total, of which seven observational studies met the inclusion criteria. The studies had medium to good quality. The pooled estimate for the association between excessive GWG and childhood overweight yielded an odds ratio (OR) of 1.38 (95% confidence interval [CI]: 1.21-1.57). The association between inadequate GWG and childhood overweight yielded an OR of 0.91 (95% CI: 0.85-0.98).

CONCLUSION

These data provide evidence for at least a 21% risk for childhood overweight related to excessive GWG. Therefore, further efforts to design appropriate interventions against excessive GWG may appear warranted.

Gestational weight gain and adiposity, fat distribution, metabolic profile, and blood pressure in offspring: the IDEFICS project

OBJECTIVE

To investigate the association between gestational weight gain (GWG) and total adiposity, body fat distribution, blood pressure (BP), and metabolic profile in offspring.

DESIGN

Cross-sectional study.

METHODS

Body mass index (BMI), waist, subscapular and tricipital skinfolds, and BP were measured and blood samples drawn in 12 775 children (aged 2-9 years) from the IDEFICS cohort. Overweight/obesity was defined by IOTF criteria. Parents filled in a questionnaire investigating child and familiar medical history and lifestyle. A section was dedicated to pregnancy history (including GWG).

RESULTS

Anthropometric indices linearly and significantly increased across GWG tertiles (BMI z-score: tertile I =0.08, 0.03-0.13; tertile II =0.16, 0.12-0.21; tertile III =0.34, 0.28-0.40, P<0.01, mean, 95% CI) by analysis of covariance (ANCOVA) adjusted by child sex, age and practice of sport, birth weight, current maternal BMI, parental education, gestational age, age at delivery, alcohol and smoking during pregnancy, maternal diabetes mellitus, gestational hypertension, and breastfeeding duration. After inclusion of BMI z-score among covariates, HbA1c significantly increased across tertiles (P=0.009) while no differences were observed for BP, serum insulin, HOMA index, blood glucose and lipids. The adjusted risk of overweight/obesity significantly increased by 14 and 22% in tertiles II and III respectively, in comparison with tertile I by logistic regression analysis controlling for covariates.

CONCLUSION

Maternal GWG is an independent predictor of total adiposity and body fat distribution in offspring during infancy. Exposure to perinatal factors should be taken into account for early prevention of overweight and obesity.

Associations of maternal weight gain in pregnancy with offspring cognition in childhood and adolescence: findings from the Avon Longitudinal Study of Parents and Children

An association of gestational weight gain (GWG) with offspring cognition has been postulated. We used data from the Avon Longitudinal Study of Parents and Children, a United Kingdom prospective cohort (1990 through the present) with a median of 10 maternal weight measurements in pregnancy. These were used to allocate participants to 2009 Institute of Medicine weight-gain categories and in random effect linear spline models. Outcomes were School Entry Assessment score (age, 4 years; n = 5,832), standardized intelligence quotient assessed by Wechsler Intelligence Scale for Children (age, 8 years; n = 5,191), and school final-examination results (age, 16 years; n = 7,339). Offspring of women who gained less weight than recommended had a 0.075 standard deviation lower mean School Entry Assessment score (95% confidence interval: -0.127, -0.023) and were less likely to achieve adequate final-examination results (odds ratio = 0.88, 95% confidence interval: 0.78, 0.99) compared with offspring of women who gained as recommended. GWG in early pregnancy (defined as 0-18 weeks on the basis of a knot point at 18 weeks) and midpregnancy (defined as 18-28 weeks on the basis of knot points at 18 and 28 weeks) was positively associated with School Entry Assessment score and intelligence quotient. GWG in late pregnancy (defined as 28 weeks onward on the basis of a knot point at 28 weeks) was positively associated with offspring intelligence quotient and with increased odds of offspring achieving adequate final-examination results in mothers who were overweight prepregnancy. Findings support small positive associations between GWG and offspring cognitive development, which may have lasting effects on educational attainment up to age 16 years.

Cardiometabolic health of children conceived by assisted reproductive technologies

The cardiometabolic health of children conceived by assisted reproductive technologies (ART) compared with children conceived without medical assistance is unclear. Although the majority of published studies evaluating height, weight, and body mass index have not found differences by method of conception, some studies have indicated differences in adiposity by more direct measures such as skinfolds and dual X-ray absorptiometry. Far fewer studies have investigated other cardiometabolic characteristics, such as blood pressure and measures of lipid and glucose metabolism. Of these studies, some indications of increased blood pressure and recent findings of vascular dysfunction among children conceived by ART compared with children conceived without ART warrant further investigation. Epigenetic differences may be the global mechanism at work, resulting from different aspects of ART treatment, such as ovarian stimulation, in vitro culture, and manipulation of sperm, among other considerations. Fetal growth and placental development may serve as mediators of these effects. Future studies should consider recruiting sufficient numbers of ART and non-ART conceived multiples and collect information on indicators of cardiometabolic health in the parents. Despite some advantages of sibling cohorts in developmental origins research, its feasibility and utility for investigating health of children conceived by ART remains debatable.

The risk of maternal obesity to the long-term health of the offspring

The prevalence of maternal obesity has risen dramatically in recent years, with approximately one in five pregnant women in the UK now classed as obese (body mass index ≥ 30 kg/m(2) ) at antenatal booking. Obesity during pregnancy has been hypothesized to exert long-term health effects on the developing child through 'early life programming'. While this phenomenon has been well studied in a maternal undernutrition paradigm, the processes by which the programming effects of maternal obesity are mediated are less well understood. In humans, maternal obesity has been associated with a number of long-term adverse health outcomes in the offspring, including lifelong risk of obesity and metabolic dysregulation with increased insulin resistance, hypertension and dyslipidaemia, as well as behavioural problems and risk of asthma. The complex relationships between the maternal metabolic milieu and the developing foetus, as well as the potential influence of postnatal lifestyle and environment, have complicated efforts to study the programming effects of maternal overnutrition in humans. This review will examine the emerging evidence from human studies linking maternal obesity to adverse offspring outcomes.

High-fat diet alters the dopamine and opioid systems: effects across development

Consumption of a high-fat diet has been linked to obesity, dyslipidemia and cardiovascular disease. Less well appreciated are adverse effects on the brain and behavior. Recent research has shown that consumption of a high-fat diet can alter gene expression within the brain, and the dopamine and opioid neurotransmitter systems appear to be vulnerable to dysregulation. This review will focus on recent reports in both humans and animal models that describe adverse effects of high-fat diet consumption on the central reward circuitry. In addition, the importance of different development windows will be discussed, with effects observed in both the prenatal/perinatal time period and with chronic high-fat diet consumption in adulthood.

Association between number of children and mortality of mothers: results of a 37-year follow-up study

PURPOSE

To examine the association between parity and long-term, all-cause mortality and mortality owing to specific causes in women.

METHODS

This prospective population-based study included 40,454 mothers who gave birth in Western Jerusalem, Israel, to 125,842 children and were followed for an average of 37 years after the birth of their first child. Cox proportional hazards models were used to evaluate long-term total and specific-cause mortality of women by their parity.

RESULTS

We found a U-shaped relationship between the number of offspring and risk of all-cause mortality in mothers. After adjustment for sociodemographic characteristics and maternal health and obstetric conditions, higher mortality rates were observed for mothers of 1 child (hazard ratio [HR], 1.18; 95% confidence interval [CI], 1.04-1.4), mothers of 5 to 9 children (HR, 1.21; 95% CI, 1.09-1.33), and mothers of 10 or more children (HR, 1.49; 95% CI, 1.12-1.99) compared with mothers of 2 to 4 children. Mortality risk from specific causes including coronary disease, circulatory disease, and cancer were increased for multiparous women.

CONCLUSIONS

In this long-term follow-up study, there was an association between number of children and mortality risk for mothers. These findings suggest that maternal pregnancies and postnatal characteristics as reflected by number of children may have consequences for long-term maternal health.

Maternal adiposity--a determinant of perinatal and offspring outcomes?

Experimental and animal data suggest that maternal obesity during pregnancy adversely affects offspring health in the short-term and the long-term. Whether these effects occur in humans and influence population health is less clear. This Review explores evidence from intervention studies and observational studies that have used designs (such as family-based comparisons and Mendelian randomization) that might help improve understanding of the causal effects of maternal obesity in humans. Collectively, human studies provide evidence that maternal overweight and obesity is causally related to pregnancy complications, increased offspring weight and adiposity at birth, and the difficulties associated with delivery of large-for-gestational-age infants. The underlying mechanisms for these effects probably involve maternal and fetal dysregulation of glucose, insulin, lipid and amino acid metabolism. Some evidence exists that extreme maternal obesity (BMI ≥40 kg/m(2)) is causally related to a long-term increase in offspring adiposity, but further exploration of this relationship is needed. High gestational weight gain may result in a long-term increase in offspring adiposity if women are already overweight or have obesity at the start of pregnancy. To date, little high-quality human evidence exists that any of these effects are mediated by epigenetic mechanisms, but approaches to appropriately test this possibility are being developed.

Maternal obesity, gestational weight gain and diet as determinants of offspring long term health

This review addresses the increasingly prolific literature from studies in man and animals suggesting that maternal obesity, a diet rich in calories or excess gestational weight gain may, through perturbation of the intrauterine environment, lead to lifelong risk of obesity and related disorders in the child. In addressing maternal- child obesity relationships it remains a challenge to distinguish the influence of the intrauterine environment from the contribution of shared genetic traits, and to adequately adjust for postnatal determinants of childhood obesity. Studies in genetically identical rodents convincingly show that maternal obesity, as well as elements of a hypercalorific diet can permanently influence offspring risk of obesity, and are these are supported by studies in larger mammals. Importantly, dissection of the mechanism in animals has led to description of novel interactive pathways between maternal environment and fetus which are amenable to investigation in humans.

Excess gestational weight gain is associated with child adiposity among mothers with normal and overweight prepregnancy weight status

There are inconsistencies in the literature regarding the association between gestational weight gain (GWG) and child adiposity. GWG is hypothesized to act on child adiposity directly through intrauterine programming and indirectly through birth weight. It is unclear if the relative importance of these pathways differs by prepregnancy BMI status. We analyzed data from 3600 participants of the nationally representative Early Childhood Longitudinal Study-Birth Cohort. Child BMI Z-score was calculated from height and weight measured at 5 y. Using linear regression, controlling for sociodemographics and family lifestyle, we examined prepregnancy BMI-specific associations between GWG and child BMI Z-score. There was a nonlinear association among normal (P < 0.001) and overweight mothers only (P = 0.013), such that GWG beyond the midpoint of the 2009 Institute of Medicine recommendations was associated with a significant increase in child BMI Z-score. After the addition of birth-weight-for-gestational-age and breastfeeding to the model, the association remained among normal-weight mothers (P = 0.005) and was slightly attenuated among overweight mothers (P = 0.09). No significant association was observed between GWG and child BMI Z-score among underweight or obese mothers. We used path analysis to decompose the total effect into direct and indirect effects. This indicated the presence of a stronger direct than indirect effect. In conclusion, low GWG is not associated with BMI Z-score among any prepregnancy BMI group. Excess GWG is associated with an increase in child BMI Z-score among normal and overweight mothers only. Prevention of excess GWG may be a strategy to prevent childhood obesity.

Invited commentary: How early in life does the risk of obesity originate?

Mothers and fathers influence the risk of obesity in their children through genetic, environmental, and behavioral factors. Unique to the mother, however, is the intrauterine environment in which the fetus develops, and it is during this time in the uterus that the risk of later obesity in the child may develop. In this issue of the Journal, Fleten et al. (Am J Epidemiol. 2012;176(2):83-92) investigate whether the intrauterine environment plays a role in the development of adiposity by comparing the association between maternal prepregnancy body mass index (BMI; measured as weight in kilograms divided by height in meters squared) and offspring BMI at 3 years of age with the paternal-offspring association at the same age in the Norwegian Mother and Child Cohort Study. In that large study of stable, relatively healthy and well-educated families, significant differences in maternal-offspring and paternal-offspring BMI associations were not identified. These findings are interpreted as indicating that the influence on the child's BMI of the intrauterine environment is less important than that of genetics and shared environment. Results from that study suggest that further consideration should be given to the specificity of the fetal overnutrition hypothesis in terms of which aspects of the intrauterine environment may influence offspring adiposity and when across the life course these effects may manifest themselves.

The Norwegian Family Based Life Course (NFLC) study: data structure and potential for public health research

OBJECTIVES

To present details of the Norwegian Family Based Life Course Study.

METHODS

All Norwegians participating in censuses from 1960 to 2001 were included. In addition to the personal identity number, we used household and family information from the 1960 census to link family members together. The NFLC study is further linked to other health registers and surveys.

RESULTS

The proportion included and alive in 1960 increased from 67 % among those born in 1900 to more than 90 % for those born after 1940. In all, 5,266,270 were included. This combined family linkage approach gave 85 % parental linkage for those born in 1940 that dropped to 20 % of those born in 1930. The proportion with misclassified parents was less than 0.5 %. In all, 3,564,582 individuals were linked to their parents.

CONCLUSIONS

The NFLC is one of the largest follow-up of individuals over several decades in their life course. The comprehensive multigenerational, family linkage within the database contributes to large-scale use of various designs for investigating life course determinants.

Lifestyle counseling during pregnancy and offspring weight development until four years of age: follow-up study of a controlled trial

BACKGROUND

Fetal conditions are known to be partly responsible for the child's risk for obesity. Our pilot study aimed to determine the effect of gestational lifestyle counseling on the offspring weight gain until 4 years of age and to estimate power for future studies.

DESIGN AND METHODS

First-time pregnant mothers participated in a controlled trial conducted in maternity health clinics during 2004 - 2006. The intervention included individual counseling on physical activity and diet, and an option to attend supervised group exercise sessions. The participant mothers (N = 109) received a follow-up questionnaire concerning 13 repeated growth measurements of their offspring. Response rate to the follow-up questionnaire was 66.1% (N = 72/109).

RESULTS

The increase of BMI z-score between 24-48 months was not significantly slower among the intervention group offspring (95% CI -0.025 to 0.009, p = 0.34) compared to control group. Z-scores for weight-for-length/height did not differ between groups when the period 0-48 months was analyzed (95% CI -0.010 to 0.014, p = 0.75).

CONCLUSIONS

In this pilot study gestational lifestyle counseling did not significantly slow the weight gain of the offspring. Gestational intervention studies with at least 300 mothers per group are needed to confirm the possible effect on offspring's risk for obesity.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN21512277.

Gestational weight gain: influences on the long-term health of the child

PURPOSE OF REVIEW

To address the recent evidence which suggests that inappropriate gestational weight gain (GWG) may have consequences that extend to the longer term health of the child.

RECENT FINDINGS

Inadequate GWG is associated with low birthweight, and excessive GWG to delivery of large for gestational age infants . Recent studies report relationships between excessive GWG and neonatal adiposity, and with childhood and adult obesity. These appear to be independent of confounders such as socioeconomic status and a shared family environment, or hereditary traits for obesity, supporting the 'developmental origins of disease' hypothesis.

SUMMARY

Because of periods of developmental plasticity, the early life metabolic environment may contribute to the risk of metabolic and cardiovascular disease in later life. The mechanisms which explain the relationships between maternal GWG and later life obesity remain unknown. Large, well conducted, intervention randomized controlled trials in pregnant women are required to address relationships between GWG and offspring risk of disease, including characterization of potential mediators. These should lead to more targeted and effective intervention strategies.