Fetal Exposure to Cannabis and Childhood Metabolic Outcomes: The Healthy Start Study

OBJECTIVE

To assess the impact of fetal exposure to cannabis on adiposity and glucose-insulin traits in early life.

RESEARCH DESIGN AND METHODS

We leveraged a subsample of 103 mother-child pairs from Healthy Start, an ethnically diverse Colorado-based cohort. Twelve cannabinoids/metabolites of cannabis (including Δ9-tetrahydrocannabinol and cannabidiol) were measured in maternal urine collected at ~27 weeks' gestation. Fetal exposure to cannabis was dichotomized as exposed (any cannabinoid > limit of detection [LOD]) and not exposed (all cannabinoids < LOD). Fat mass and fat-free mass were measured via air displacement plethysmography at follow-up (mean age: 4.7 years). Glucose and insulin were obtained after an overnight fast. Generalized linear models estimated the associations between fetal exposure to cannabis with adiposity measures (fat mass [kg], fat-free mass [kg], adiposity [fat mass percentage], body mass index [BMI], and BMI z-scores) and metabolic measures (glucose [mg/dL], insulin [uIU/mL], and homeostatic model assessment of insulin resistance [HOMA-IR]).

RESULTS

Approximately 15% of the women had detectable levels of any cannabinoid, indicating fetal exposure to cannabis. Exposed offspring had higher fat mass (1.0 kg; 95% CI, 0.3-1.7), fat-free mass (1.2 kg; 95% CI, 0.4-2.0), adiposity (2.6%; 95% CI, 0.1-5.2), and fasting glucose (5.6 mg/dL; 95% CI, 0.8-10.3) compared with nonexposed offspring. No associations were found with fasting insulin (in the fully adjusted model), HOMA-IR, BMI, or BMI z-scores.

CONCLUSIONS

We provide novel evidence to suggest an association between fetal exposure to cannabis with increased adiposity and fasting glucose in childhood, a finding that should be validated in other cohorts.

Association of In Utero Exposures With Risk of Early Natural Menopause

Suboptimal pregnancy conditions may affect ovarian development in the fetus and be associated with early natural menopause (ENM) for offspring. A total of 106,633 premenopausal participants in Nurses' Health Study II who provided data on their own prenatal characteristics, including diethylstilbestrol (DES) exposure, maternal cigarette smoking exposure, multiplicity, prematurity, and birth weight, were followed from 1989 to 2017. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of in utero exposures with ENM. During 1.6 million person-years of follow-up, 2,579 participants experienced ENM. In multivariable models, women with prenatal DES exposure had higher risk of ENM compared with those without it (HR = 1.33, 95% CI: 1.06, 1.67). Increased risk of ENM was observed for those with low (<5.5 pounds (<2.5 kg)) versus normal (7.0-8.4 pounds (3.2-3.8 kg)) birth weight (HR = 1.21, 95% CI: 1.01, 1.45). Decreasing risk was observed per 1-pound (0.45-kg) increase in birth weight (HR = 0.93, 95% CI: 0.90, 0.97). Prenatal smoking exposure, being part of a multiple birth, and prematurity were not associated with ENM. In this large cohort study, lower birth weight and prenatal DES exposure were associated with higher risk of ENM. Our results support a need for future research to examine in utero exposures that may affect offspring reproductive health.

Developmental origins and transgenerational inheritance of polycystic ovary syndrome

BACKGROUND

There has been increasing awareness that polycystic ovary syndrome (PCOS) phenotypes may represent a mismatch between ancient genetically programmed metabolic and reproductive survival mechanisms and modern lifestyle practices. In-utero developmental programming of metabolic and endocrine pathways may play an important role in activating gene variants that predispose the offspring to develop PCOS when exposed to specific postnatal conditions. Postnatal exposure to lifestyle factors such as poor-quality diet and endocrine disrupting chemicals may modulate epigenetically programmed pathways that result in the observed pathophysiological changes and clinical features seen in women with PCOS.

AIM

To review the developmental origins and transgenerational transmission of PCOS and the impact of lifestyle, androgens and endocrine disrupting chemicals on fetal epigenetic programming.

MATERIALS AND METHODS

The literature was reviewed using Google, Google Scholar, Medline and PubMed databases. The results are presented as a narrative review.

RESULTS

Human observational and animal experimental data support the hypothesis that PCOS is an inherited condition that arises as a result of developmental programming of normal gene variants. It is likely that these genes can be amplified by in-utero androgen exposure and activated by a range of postnatal lifestyle and environmental factors. Endocrine disrupting chemicals have the potential to influence developmental programming of PCOS susceptibility genes.

CONCLUSIONS

The current evidence suggests that developmental epigenetic programming following exposure to an adverse maternal metabolic and endocrine environment contributes to the pathogenesis of PCOS. Lifestyle interventions, as recommended by the International Guidelines, have the potential to reduce both symptoms and transgenerational transmission of PCOS.

Fetal origins-A life cycle model of health and aging from conception to death

The fetal origins hypothesis suggests that health and nutrition shocks in utero are causally related to health deficits in old age. It has received considerable empirical support, both within epidemiology and economics but so far it has not been integrated into a life cycle theory of human aging and longevity. The present study shows that the health deficit model, based on the frailty index developed in gerontology, generates shock amplification consistent with the hypothesis. In order to discuss human health over the life cycle from conception to death, we develop a theory of ontogenetic growth and health in utero and during childhood, unify it with the health deficit model of adult aging, and discuss the transmission of early-life shocks to late-life health deficit accumulation.

Perinatal health among 1 million Chinese-Americans

The literature on "missing girls" suggests a net preference for sons both in China and among Chinese immigrants to the West. Perhaps surprisingly, we find that newborn Chinese-American girls are treated more intensively in US hospitals: they are kept longer following delivery, have more medical procedures performed, and have more hospital charges than predicted (by the non-Chinese gender difference). What might explain more aggressive medical treatment? We posit that hospitals are responding to worse health at birth of Chinese-American girls. We document higher rates of low birth weight, congenital anomalies, maternal hypertension, and lower APGAR scores among Chinese American girls - outcomes recorded prior to intensive neonatal medical care and relative to the non-Chinese gender gap. To the best of our knowledge, we are the first to find that son preference may also compromise "survivor" health at birth. On net, compromised newborn health seems to outweigh the benefit of more aggressive neonatal hospital care for girls. Relative to non-Chinese gender differences, death on the first day of life and in the post-neonatal period is more common among Chinese-American girls, i.e. later than sex selection is typically believed to occur.

A toolkit for the application of placental-fetal molecular biomarkers in epidemiologic studies of the fetal origins of chronic disease

Purpose of review

In this review, we provide essential background knowledge and an analytical framework for the application of placental-fetal molecular biomarkers in fetal origins chronic disease epidemiology. The widely available and highly quantitative placental hormone human chorionic gonadotropin (hCG) is used as an example. hCG is currently used for diagnosing fetal genetic disorders; yet it can and should be expanded to understanding the fetal origins of chronic diseases. We provide justification and methods to do this.

Recent findings

Ten papers published in the last 5 years were identified with supportive findings relevant to the application of biomarkers of hCG in epidemiologic studies on the developmental origins of health and disease (DOHaD).

Summary

There is increasing and consistent evidence that placental-fetal biomarkers may be highly informative in observational studies, as exemplified by hCG, with the correct approaches for measurement and data analysis.

Birth Weight and Stroke in Adult Life: Genetic Correlation and Causal Inference With Genome-Wide Association Data Sets

Objective

Prior studies have shown that there is an inverse association between birth weight and stroke in adulthood; however, whether such association is causal remains yet known and those studies cannot distinguish between the direct fetal effect and the indirect maternal effect. The aim of the study is to untangle such relationship using novel statistical genetic approaches.

Methods

We first utilized linkage disequilibrium score regression (LDSC) and Genetic analysis incorporating Pleiotropy and Annotation (GPA) to estimate the overall genetic correlation between birth weight and stroke. Then, with a set of valid birth-weight instruments which had adjusted fetal and maternal effects, we performed a two-sample Mendelian randomization (MR) to evaluate its causal effect on stroke based summary statistics from large scale genome-wide association study (GWAS) (n = 264,498 for birth weight and 446,696 for stroke). We further validated the MR results with extensive sensitivity analyses.

Results

Both LDSC and GPA demonstrated significant evidence of shared maternal genetic foundation between birth weight and stroke, with the genetic correlation estimated to −0.176. However, no fetal genetic correlation between birth weight and stroke was detected. Furthermore, the inverse variance weighted MR demonstrated the maternally causal effect of birth weight on stroke was 1.12 (95% confidence interval [CI] 1.00–1.27). The maternal ORs of birth weight on three subtypes of stroke including cardioembolic stroke (CES), large artery stroke (LAS) and small vessel stroke (SVS) were 1.16 (95% CI 0.93–1.43), 1.50 (95% CI 1.14–1.96) and 1.47 (95% CI 1.15–1.87), respectively. In contrast, no fetal causal associations were found between birth weight and stroke or the subtypes. Those results were robust against extensive sensitivity analyses, with Egger regression ruling out the possibility of pleiotropy and multivariable MR excluding the likelihood of confounding or mediation effects of other risk factors of stroke.

Conclusion

This study provides empirically supportive evidence on the fetal developmental origins of stroke and its subtypes. However, further investigation is warranted to understand the pathophysiological role of low birth weight in developing stroke.

Intracytoplasmic sperm injection and fetal origins of autism spectrum disorder: an intriguing, though controversial association

Latest knowledge assigns the origins of autism spectrum disorder (ASD)-currently affecting 1% of children- to intrauterine life, when fetal brain develops. Besides genetics, environmental factors, responsible for epigenetic changes contributed to its rising incidence. In vitro fertilization (IVF) and the most widely used intracytoplasmic sperm injection (ICSI) are implicated in epigenetic changes. A series of studies examined the impact of ICSI on ASD in the offspring. Results are usually conflicting, due to inherent problems of study design and power, mixed IVF/ICSI cases and not exclusively ASD diagnoses included. Furthermore, preterm birth, low birthweight infants, advanced parental age, hormonal disturbances, all associated with ICSI, are known factors affecting ASD. While solid data supporting ICSI contribution to currently alarming ASD increase are lacking, exploration of underlying molecular mechanisms would strengthen possible associations. In the meanwhile, ICSI use should be restricted to male-factor infertility cases.

Detecting the Effects of Early-Life Exposures: Why Fecundity Matters

Prenatal exposures have meaningful effects on health across the lifecourse. Innovations in causal inference have shed new light on these effects. Here, we motivate the importance of innovation in the characterization of fecundity, and prenatal selection in particular. We argue that such innovation is crucial for expanding knowledge of the fetal origins of later life health. Pregnancy loss is common, responsive to environmental factors, and closely related to maternal and fetal health outcomes. As a result, selection into live birth is driven by many of the same exposures that shape the health trajectories of survivors. Lifecourse effects that are inferred without accounting for these dynamics may be significantly distorted by survival bias. We use a set of Monte Carlo simulations with realistic parameters to examine the implications of prenatal survival bias. We find that even in conservatively specified scenarios, true fetal origin effects can be underestimated by 50% or more. In contrast, effects of exposures that reduce the probability of prenatal survival but improve the health of survivors will be overestimated. The absolute magnitude of survival bias can even exceed small effect sizes, resulting in inferences that beneficial exposures are harmful or vice-versa. We also find reason for concern that moderately sized true effects, underestimated due to failure to account for selective survival, are missing from scientific knowledge because they do not clear statistical significance filters. This bias has potential real-world costs; policy decisions about interventions to improve maternal and infant health will be affected by underestimated program impact.

Relationship between early-life nutrition and ages at menarche and first pregnancy, and childbirth rates of young adults: Evidence from APCAPS in India

India's Integrated Child Development Services (ICDS) provides daily supplementary nutrition and other public health services to women and children. We estimated associations between exposure to early‐childhood ICDS nutrition and adult reproductive outcomes. During 1987–1990, a balanced protein–calorie supplement called “upma”—made from locally available corn–soya ingredients—was rolled out by subdistricts near Hyderabad and offered to pregnant women and children under age 6 years. In a controlled trial, 15 villages received the supplement and 14 did not. We used data from a 2010–2012 resurvey of adults born during the trial (n = 715 in intervention and n = 645 in control arms). We used propensity score matching methods to estimate the associations between birth in an intervention village and menarcheal age, age at first pregnancy, and fertility of adults. We found that women born in the intervention group during the trial, as compared with the control group, had menarche 0.45 (95% confidence interval [CI: 0.22, 0.68]; p < .001) years later and first pregnancy 0.53 (95% CI [0.04, 1.02]; p < .05) years later. Married women from the intervention group had menarche 0.36 (95% CI [0.09, 0.64]; p < .01) years later, first cohabitation with partner 0.8 (95% CI [0.27, 1.33]; p < .01) years later, and first pregnancy 0.53 (95% CI [0.04, 1.02]; p < .05) years later than married women in the control group. There was no significant difference between intervention and control group women regarding whether they had at least one childbirth or the total number of children born. The findings were similar when we employed inverse propensity score weighted regression models.

Prenatal influences on bone health in children

INTRODUCTION

Optimising bone health might reduce the burden of both fractures in childhood and fragility fractures in later life. A number of maternal dietary and non-dietary factors have been identified that might influence offspring bone health and represent targets for intervention.

AREAS COVERED

This article will outline the accrual of bone mineral throughout the life course and how observational and intervention studies have shown that maternal diet, in particular maternal calcium and 25-hydroxyvitamin D [25(OH)D] status, and lifestyle are associated with offspring bone mineralization. Studies examining the effects of maternal micronutrient supplementation on offspring bone mineral density (BMD) will also be discussed.

EXPERT COMMENTARY

There is a wealth of observational evidence relating maternal diet to offspring BMD. However, high quality randomized controlled trials, such as the ongoing MAVIDOS study, are needed before these findings can be definitively translated into public health advice.

Glucocorticoids, antenatal corticosteroid therapy and fetal heart maturation

Glucocorticoids are essential in mammals to mature fetal organs and tissues in order to survive after birth. Hence, antenatal glucocorticoid treatment (termed antenatal corticosteroid therapy) can be life-saving in preterm babies and is commonly used in women at risk of preterm birth. While the effects of glucocorticoids on lung maturation have been well described, the effects on the fetal heart remain less clear. Experiments in mice have shown that endogenous glucocorticoid action is required to mature the fetal heart. However, whether the potent synthetic glucocorticoids used in antenatal corticosteroid therapy have similar maturational effects on the fetal heart is less clear. Moreover, antenatal corticosteroid therapy may increase the risk of cardiovascular disease in adulthood. Here, we present a narrative review of the evidence relating to the effects of antenatal glucocorticoid action on the fetal heart and discuss the implications for antenatal corticosteroid therapy.

Developmental origins of health and disease: current knowledge and potential mechanisms

Epidemiologic and clinical research has provided a large body of evidence supporting the developmental origins of health and disease (DOHaD), but there has been a relative dearth of mechanistic studies in humans due to the complexity of working with large, longitudinal cohorts. Nonetheless, animal models of undernutrition have provided substantial evidence for the potential epigenetic, metabolic, and endocrine mechanisms behind DOHaD. Furthermore, recent research has explored the interaction between the environment and the gastrointestinal system by investigating how the gut microbial ecology may impact the capacity for nutrient processing and absorption in a manner that may limit growth. This review presents a summary of current research that supports the concept of DOHaD, as well as potential mechanisms and interactions that explain how nutrition in utero and during early childhood influences lifelong health.

Early-Life Nutrition Is Associated Positively with Schooling and Labor Market Outcomes and Negatively with Marriage Rates at Age 20-25 Years: Evidence from the Andhra Pradesh Children and Parents Study (APCAPS) in India

Background

India's Integrated Child Development Services (ICDS) is among the world's largest public nutritional programs, providing daily nutritional supplements and other public health and educational services to pregnant and nursing women, children aged <6 y, and adolescent girls.

Objective

We estimated the long-term association between early-childhood ICDS nutrition and adult outcomes.

Methods

We used follow-up data from a controlled nutritional trial conducted during 1987-1990 in 29 villages near the city of Hyderabad. In 15 intervention villages, a balanced protein-calorie supplement-made from locally available corn-soya ingredients and called upma-was offered to pregnant women and to children <6 y old. No supplement was offered in the 14 control villages. During 2010-2012, adults born during the trial were re-surveyed (n = 715 in the intervention arm and n = 645 in the control arm). We used probit regression and propensity score-matching methods to estimate the association between birth in an intervention village and rates of secondary and graduate education completion, marriage, and employment or enrollment in higher education of these adults.

Results

Adults born in the intervention group during the trial, compared with the control group, were 9% (95% CI: 0.04, 0.14; P < 0.01) more likely to complete secondary school and 11% (95% CI: 0.06, 0.15; P < 0.01) more likely to complete graduate education, were 6% (95% CI: -0.11, -0.01; P < 0.05) less likely to be ever-married at age 20-25 y, and were 5% (95% CI: 0, 0.11; P < 0.05) more likely to be employed or enrolled in higher education. The estimated associations for graduate education completion and employment-study rates were greater for men, whereas the associations for secondary education and ever-married rates were greater for women.

Conclusion

Exposure to nutritional supplement in utero or during the first 3 y of life was associated with improved adult educational and employment outcomes and lower marriage rates in India.

Prenatal Temperature Shocks Reduce Cooperation: Evidence from Public Goods Games in Uganda

Climate change has not only led to a sustained rise in mean global temperature over the past decades, but also increased the frequency of extreme weather events. This paper explores the effect of temperature shocks in utero on later-life taste for cooperation. Using historical climate data combined with data on child and adult behavior in public goods games, I show that abnormally high ambient temperatures during gestation are associated with decreased individual contributions to the public good in a statistically and economically significant way. A 1 standard deviation rise in mean ambient temperature during gestation is associated with a 10% point decrease in children's cooperation rate in a dichotomous public goods game, and the reduced taste for cooperation lasts into adulthood.

Relationship between season of birth, temperature exposure, and later life wellbeing

We study how exposure to extreme temperatures in early periods of child development is related to adult economic outcomes measured 30 y later. Our analysis uses administrative earnings records for over 12 million individuals born in the United States between 1969 and 1977, linked to fine-scale, daily weather data and location and date of birth. We calculate the length of time each individual is exposed to different temperatures in utero and in early childhood, and we estimate flexible regression models that allow for nonlinearities in the relationship between temperature and long-run outcomes. We find that an extra day with mean temperatures above 32 °C in utero and in the first year after birth is associated with a 0.1% reduction in adult annual earnings at age 30. Temperature sensitivity is evident in multiple periods of early development, ranging from the first trimester of gestation to age 6-12 mo. We observe that household air-conditioning adoption, which increased dramatically over the time period studied, mitigates nearly all of the estimated temperature sensitivity.

Fetal origins of autism spectrum disorders: the non-associated maternal factors

Aim:

Several population-based studies have been conducted to determine whether maternal exposures are involved in the pathophysiology of autism spectrum disorder (ASD). We review these studies and describe the factors not associated with increased risk for ASD development.

Methods:

We identified studies describing associations between maternal exposures and ASD development. These studies include the Childhood Autism Risks from Genetics and the Environment, Nurses’ Health Study II, and the Swedish population registry.

Results:

Factors not associated with ASD development include Type 2 and gestational diabetes, chronic hypertension, fever treated with antipyretic medication, autoimmune disease and short interpregnancy intervals.

Conclusion:

There is increasing evidence that maternal exposures are involved in the pathophysiology of ASD in the developing fetus.

Lay Abstract: Autism spectrum disorder currently affects one in 68 children in the USA, with up to one in 42 boys. Its underlying etiology is largely unknown. Although autism was once considered a childhood disease, efforts for early detection led to the realization that it might originate at a much earlier stage, namely fetal life. Several maternal risk factors have recently been studied to establish associations with autism in the offspring. In this review, we present the maternal risk factors that were not found to have such associations.

Nonlinear Relationship between Birth Weight and Visceral Fat in Adolescents

OBJECTIVE

To determine the association of birth weight with abdominal fat distribution and markers known to increase risk for cardiovascular disease and type 2 diabetes in adolescents.

STUDY DESIGN

In 575 adolescents aged 14-18 years (52% female, 46% black), birth weight was obtained by parental recall. Fasting blood samples were measured for glucose, insulin, lipids, adiponectin, leptin, and C-reactive protein. Subcutaneous abdominal adipose tissue and visceral adipose tissue were assessed by magnetic resonance imaging.

RESULTS

When we compared markers of cardiometabolic risk across tertiles of birth weight, adjusting for age, sex, race, Tanner stage, physical activity, socioeconomic status, and body mass index, there were significant U-shaped trends for homeostasis model assessment of insulin resistance, leptin, and visceral adipose tissue (all Pquadratic < .05). A significant linear downward trend across tertiles of birth weight was observed for triglycerides (Plinear = .03). There were no differences in fasting glucose, blood pressure, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, adiponectin, C-reactive protein, or subcutaneous abdominal adipose tissue across tertiles of birth weight.

CONCLUSIONS

Our data suggest that both low and high birth weights are associated with greater visceral adiposity and biomarkers implicated in insulin resistance and inflammation in adolescents.

Lower resting energy expenditure and fat oxidation in Native American and Hispanic infants born to mothers with diabetes

OBJECTIVE

To determine whether exposure to diabetes in utero affects resting energy expenditure (REE) and fuel oxidation in infants.

STUDY DESIGN

At 35 ± 5 days after birth, body composition and REE were measured in full-term offspring of Native American and Hispanic women with either well-controlled diabetes (13 girls, 11 boys) or normal healthy pregnancies (18 girls, 17 boys).

RESULTS

Control of dysglycemia during gestation in the women with diabetes mellitus met current clinical standards, shown by average glycated hemoglobin (5.9 ± 0.2%; 40.6 ± 2.3 mmol/mol). Infant body mass (offspring of women with diabetes: 4.78 ± 0.13, control offspring: 4.56 ± 0.08 kg) and body fatness (offspring of women with diabetes: 25.2 ± 0.6, control offspring: 24.2 ± 0.5 %) did not differ between groups. REE, adjusted for lean body mass, was 14% lower in offspring of women with diabetes (41.7 ± 2.3 kJ/h) than control offspring (48.6 ± 2.0, P = .025). Fat oxidation was 26% lower in offspring of women with diabetes (0.54 ± 0.05 g/h) than control offspring (0.76 ± 0.04, P < .01) but carbohydrate oxidation did not differ. Thus, fat oxidation accounted for a lower fraction of REE in the offspring of women with diabetes (49 ± 4%) than control offspring (60 ± 3%, P = .022). Mothers with diabetes were older and had higher prepregnancy body mass index than control mothers.

CONCLUSIONS

Well-controlled maternal diabetes did not significantly affect body mass or composition of offspring at 1-month old. However, infants with mothers with diabetes had reduced REE and fat oxidation, which could contribute to adiposity and future disease risk. Further studies are needed to assess the impact differences in age and higher prepregnancy body mass index.

Prenatal famine exposure and adult mortality from cancer, cardiovascular disease, and other causes through age 63 years

Nutritional conditions in early life may affect adult health, but prior studies of mortality have been limited to small samples. We evaluated the relationship between pre-/perinatal famine exposure during the Dutch Hunger Winter of 1944-1945 and mortality through age 63 years among 41,096 men born in 1944-1947 and examined at age 18 years for universal military service in the Netherlands. Of these men, 22,952 had been born around the time of the Dutch famine in 6 affected cities; the remainder served as unexposed controls. Cox proportional hazards models were used to estimate hazard ratios for death from cancer, heart disease, other natural causes, and external causes. After 1,853,023 person-years of follow-up, we recorded 1,938 deaths from cancer, 1,040 from heart disease, 1,418 from other natural causes, and 523 from external causes. We found no increase in mortality from cancer or cardiovascular disease after prenatal famine exposure. However, there were increases in mortality from other natural causes (hazard ratio = 1.24, 95% confidence interval: 1.03, 1.49) and external causes (hazard ratio = 1.46, 95% confidence interval: 1.09, 1.97) after famine exposure in the first trimester of gestation. Further follow-up of the cohort is needed to provide more accurate risk estimates of mortality from specific causes of death after nutritional disturbances during gestation and very early life.

The role of TGF-β in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by chronic oligoanovulation and hyperandrogenism and associated with insulin resistance, type 2 diabetes, and cardiovascular risk. In recent years, genetic studies have linked PCOS to a dinucleotide marker D19S884 in the fibrillin 3 gene. Fibrillins make up the major component of microfibrils in the extracellular matrix (ECM) and interact with molecules in the ECM to regulate transforming growth factor β (TGF-β) signaling. Therefore, variations in fibrillin 3 and subsequent dysregulation of TGF-β may contribute to the pathogenesis of PCOS. Here, we review the evidence from genetic studies supporting the role of TGF-β in PCOS and describe how TGF-β dysregulation may contribute to (1) the fetal origins of PCOS, (2) reproductive abnormalities in PCOS, and (3) cardiovascular and metabolic abnormalities in PCOS.

Research review: maternal prenatal distress and poor nutrition - mutually influencing risk factors affecting infant neurocognitive development

BACKGROUND

Accumulating data from animal and human studies indicate that the prenatal environment plays a significant role in shaping children's neurocognitive development. Clinical, epidemiologic, and basic science research suggests that two experiences relatively common in pregnancy - an unhealthy maternal diet and psychosocial distress - significantly affect children's future neurodevelopment. These prenatal experiences exert their influence in the context of one another and yet, almost uniformly, are studied independently.

SCOPE AND METHOD OF REVIEW

In this review, we suggest that studying neurocognitive development in children in relation to both prenatal exposures is ecologically most relevant, and methodologically most sound. To support this approach, we selectively review two research topics that demonstrate the need for dual exposure studies, including exemplar findings on (a) the associations between pregnant women's inadequate maternal intake of key nutrients - protein, fat, iron, zinc, and choline - as well as distress in relation to overlapping effects on children's neurocognitive development; and (b) cross-talk between the biology of stress and nutrition that can amplify each experience for the mother and fetus,. We also consider obstacles to this kind of study design, such as questions of statistical methods for 'disentangling' the exposure effects, and aim to provide some answers.

CONCLUSION

Studies that specifically include both exposures in their design can begin to determine the relative and/or synergistic impact of these prenatal experiences on developmental trajectories - and thereby contribute most fully to the understanding of the early origins of health and disease.

Foetal origins of depression? A systematic review and meta-analysis of low birth weight and later depression

BACKGROUND

The foetal origins hypothesis suggests an association between low birth weight and later depression, yet evidence supporting this association has been inconsistent.

METHOD

We systematically reviewed evidence for an association between low birth weight and adult depression or psychological distress in the general population by meta-analysis. We searched EMBASE, Medline, PsycINFO and ISI Web of Science for studies reporting observational data with low birth weight as the exposure and self- or clinician-rated depression or psychological distress measures as an outcome. Selective studies of exposures such as famine or outcomes such as severe illness only were excluded. Altogether,1454 studies were screened for relevance, 26 were included in the qualitative synthesis, 18 were included in the meta-analysis. A random effects meta-analysis method was used to obtain a pooled estimate of effect size.

RESULTS

The odds of depression or psychological distress was greater for those of low birth weight (<2500 g) compared to those of normal birth weight (>2500 g) or greater [odds ratio (OR) 1.15, 95% confidence intervals (CI) 1.00-1.32]. However, this association became non-significant after trim-and-fill correction for publication bias (OR 1.08, 95% CI 0.92-1.27). Using meta-regression, no differences in effect size were observed by gender, outcome measure of depression or psychological distress, or whether the effect size was adjusted for possible confounders.

CONCLUSIONS

We found evidence to support a weak association between low birth weight and later depression or psychological distress, which may be due to publication bias. It remains possible that the association may vary according to severity of symptoms or other factors.

Prenatal and perinatal characteristics associated with pediatric-onset inflammatory bowel disease

BACKGROUND

The majority of studies that report early life risk factors for pediatric-onset inflammatory bowel disease (IBD) do not account for potential confounding, which can lead to spurious associations and incorrect inferences.

AIMS

To assess the relationship between prenatal and perinatal characteristics and the risk of pediatric-onset IBD accounting for potential confounding.

METHODS

We conducted a nested case-control study of 189 cases aged ≤18 years and 3,080 age- and membership-matched controls born at a Kaiser Permanente Northern California facility between 1984 and 2006. The cases were diagnosed with IBD between 1996 and 2006 and diagnosis was confirmed by chart review. We obtained prenatal and perinatal characteristics from the electronic clinical records of the mother and child. Conditional logistic regression was used to assess the associations between these factors and risk of incident IBD, Crohn's disease, and ulcerative colitis.

RESULTS

In analyses accounting for confounding, maternal IBD (odds ratio [OR] 5.1, 95 % confidence interval [CI] 2.0-12.9) and white race (OR 2.3, 95 % CI 1.6-3.2) were the only factors statistically associated with pediatric-onset IBD. Maternal respiratory infection during pregnancy (OR 2.0, 95 % CI 1.0-4.0), age < 20 years (OR 2.0, 95 % CI 0.8-4.7) and gestational hypertension (OR 1.7, 95 % CI 1.0-2.7) were associated with pediatric-onset IBD, but did not achieve statistical significance.

CONCLUSIONS

Maternal history of IBD and race were the only characteristics of those that we examined that were associated with the development of pediatric IBD in this well-documented population of cases and matched controls.

Birth weight, postnatal weight change, and risk for high blood pressure among chinese children

BACKGROUND

It is hypothesized that a physiological predisposition toward hypertension results from a combination of intrauterine growth restriction or overgrowth and excessive postnatal weight gain. Previous studies were conducted largely in Western countries however the hypothesis may also be relevant in developing countries where metabolic disorders are increasing.

OBJECTIVE

We investigated the association of birth weight and postnatal weight gain with hypertension among Chinese children.

METHODS

A population based study was conducted among 15 600 children aged 3 to 6 years from Tianjin, China. Weight was expressed as z scores. Postnatal weight gain was defined as changes in z scores from birth to 3 to younger than 4 years, 4 to younger than 5 years, and 5 to 6 years. Hypertension was defined as greater than the 90th percentile of either systolic or diastolic blood pressure. Logistic regression-derived odds ratios and 95% confidence intervals were generated to estimate the association between birth weight and postnatal weight gain with hypertension risk in childhood.

RESULTS

Birth weight was positively associated with childhood hypertension in boys and girls (odds ratios [95% confidence interval] comparing extreme quartiles [high versus low] were 5.67 [3.83-8.39] and 2.58 [3.83-8.39], respectively). Postnatal weight gain was positively associated with hypertension and the association did not significantly vary by birth size for gestational age.

CONCLUSIONS

Greater birth weight or postnatal weight gain was associated with increased childhood hypertension risk, suggesting that intrauterine growth and postnatal weight gain may have implications on health during childhood.

Children of addicted women

The purpose of this article was to review follow up studies of children with prenatal drug exposure from preschool through adolescence. Specifically, the authors focus on the effects of prenatal exposure to cocaine, methamphetamine, and opiates on behavior and development. The largest number of studies have examined cocaine-exposed children. The authors identified 42 studies that suggest that there are unique effects of prenatal cocaine exposure on 4- to 13-year-old children, particularly in the areas of behavior problems, attention, language, and cognition. In addition, studies make reasonable attempts to control for possible confounding factors. Systematic research on the long-term effects of prenatal methamphetamine exposure is just beginning but seems to be showing similar effects to that of cocaine. The literature on the on the long-term effects of children with prenatal opiate exposure is more substantial than the methamphetamine literature but it is still relatively sparse and surprising in that there is little recent work. Thus, there are no studies on the current concerns with opiates used for prescription mediation. There is a growing literature using neuroimaging techniques to study the effects of prenatal drug exposure that holds promise for understanding brain/behavior relationships. In addition to pharmacological and teratogenic effects, drugs can also be viewed from a prenatal stressor model. The author discuss this "fetal origins" approach that involves fetal programming and the neuroendocrine system and the potential implications for adolescent brain and behavioral development.