Update: consequences of abnormal fetal growth

Association between sleep during pregnancy and birth outcomes: a prospective cohort study

OBJECTIVE

A prospective cohort study was conducted to investigate sleep status during the early and second trimester of pregnancy in pregnant women on adverse birth outcome, such as preterm birth, low birth weight and small for gestational age.

METHODS

Multivariable logistic regression models were used to analyze the association of sleep status during the early and second trimester of pregnancy with adverse birth outcomes and generated the odds ratio and 95% confidence interval.

RESULTS

5,418 pregnant women were included in the analysis. In the multivariable model, compared with 7.1-8 h/night, sleep ≤ 7 h/night during second trimester increases the risk of preterm birth (OR: 1.43, 95% CI: 1.12,1.85), and the risk of preterm birth was decreased in pregnant women who slept > 9 h/night (OR: 0.79, 95% CI: 0.53,0.93). Sleep quality, and sleep changes in the early and second trimesters, and sleep duration in the early pregnancy were not statistically associated with preterm birth, low birth weight and small for gestational age.

CONCLUSIONS

Short sleep duration during pregnancy is associated with a higher risk of preterm birth and longer sleep duration at night is associated with a lower risk of preterm birth, but the latter needs further verification. Sleep status during pregnancy was not associated with low birth weight and small for gestational age. In order to reduce risk of adverse birth outcomes, sleep problems in pregnant women should be strengthened during pregnancy care.

CLINICAL TRIAL NUMBER

Not applicable.

Small for gestational age in twin pregnancies and the risk of offspring pediatric neurologic morbidity

OBJECTIVES

Small for gestational age (SGA) singletons are at increased risk for neurodevelopmental abnormalities. Scarce data exist regarding the long-term implications of SGA in twins. We opted to study the association between SGA of one twin and long-term neurologic related morbidity in dichorionic diamniotic twins.

STUDY DESIGN

A population-based retrospective cohort study including consecutive dichorionic diamniotic twins, born between the years 1991 and 2021 at a tertiary medical center was conducted. Total and subtypes of neurologic related pediatric hospitalizations among SGA versus non-SGA twins were compared. A Kaplan-Meier survival curve was used to compare the cumulative neurologic morbidity incidence, and a Cox proportional hazards model was constructed to adjust for confounders.

RESULTS

The study population included 4222 newborns; 180 (4.3%) were SGA. Rate of long-term neurologic related hospitalizations was comparable between the two groups (8.7 vs. 8.0%, p = 0.755; Kaplan-Meier survival curve Log-rank p = 0.652). Using a Cox proportional hazards model, controlling for gender and birth order, no association was found between SGA and the risk for subsequent neurologic pediatric morbidity of the offspring (Adjusted HR = 1.0, 95% CI 0.6-1.8, p = 0.973).

CONCLUSIONS

SGA is not associated with an increased risk for long-term pediatric neurologic morbidity in dichorionic diamniotic twins.

Early postnatal moderate catch‑up growth in rats with nutritional intrauterine growth restriction preserves pulmonary vascular and cognitive function in adulthood

Intrauterine growth restriction (IUGR) with rapid postnatal catch-up growth is strongly associated with pulmonary vascular dysfunction in adulthood, whereas IUGR with delayed growth in early postnatal life results in long-term brain deficits. In the present study, it was hypothesized that IUGR with early moderate catch-up growth may alleviate pulmonary vascular remodeling in adulthood without affecting memory function. An IUGR model was established by restricting maternal nutrition during pregnancy. Different growth patterns were achieved by adjusting the litter size in each group during lactation. Rats meeting the weight requirement at weaning were selected for subsequent studies at three time points (3, 9 and 13 weeks). Cognitive function was evaluated using a Y-maze. Invasive hemodynamic measurements were conducted to measure the mean pulmonary arterial pressure (mPAP). In addition, primary pulmonary artery smooth muscle cells (PASMCs) and pulmonary vascular endothelial cells (PVECs) were cultured to investigate their role in the increase in mPAP following rapid catch-up growth. The results showed that memory function deficits in the rats in the delayed growth group were associated with reduced proliferation of neural stem cells in the subgranular zone of the hippocampus. Furthermore, moderate catch-up growth at the three time points improved memory function while maintaining a normal mPAP. In adult IUGR rats experiencing rapid catch-up growth, although memory function improved, elevated mPAP and medial thickening of pulmonary arterioles were observed. Additionally, PASMCs exhibited excessive proliferation, migration and anti-apoptotic activity in the rapid catch-up group, and PVECs also displayed excessive proliferation. These results suggested that moderate catch-up growth after IUGR is a better strategy for optimal cognition and cardiovascular health in adulthood compared with rapid catch-up growth or delayed growth.

Dysfunctional Postnatal Mitochondrial Energy Metabolism in a Patient with Neurodevelopmental Defects Caused by Intrauterine Growth Restriction Due to Idiopathic Placental Insufficiency

We report the case of a four-year-old male patient with a complex medical history born prematurely as the result of intrauterine growth restriction due to placental insufficiency. His clinical manifestations included severe neurodevelopmental deficits, global developmental delay, Pierre-Robin sequence, and intractable epilepsy with both generalized and focal features. The proband's low levels of citrulline and lactic acidosis provoked by administration of Depakoke were evocative of a mitochondrial etiology. The proband's genotype-phenotype correlation remained undefined in the absence of nuclear and mitochondrial pathogenic variants detected by deep sequencing of both genomes. However, live-cell mitochondrial metabolic investigations provided evidence of a deficient oxidative-phosphorylation pathway responsible for adenosine triphosphate (ATP) synthesis, leading to chronic energy crisis in the proband. In addition, our metabolic analysis revealed metabolic plasticity in favor of glycolysis for ATP synthesis. Our mitochondrial morphometric analysis by transmission electron microscopy confirmed the suspected mitochondrial etiology, as the proband's mitochondria exhibited an immature morphology with poorly developed and rare cristae. Thus, our results support the concept that suboptimal levels of intrauterine oxygen and nutrients alter fetal mitochondrial metabolic reprogramming toward oxidative phosphorylation (OXPHOS) leading to a deficient postnatal mitochondrial energy metabolism. In conclusion, our collective studies shed light on the long-term postnatal mitochondrial pathophysiology caused by intrauterine growth restriction due to idiopathic placental insufficiency and its negative impact on the energy-demanding development of the fetal and postnatal brain.

Inverse association between adult height and diabetes risk in a cohort study of Chinese population

Recent studies linking adult height to diabetes risk remain controversial and few were from Asia. This study, therefore, aimed to explore the association of adult height with diabetes risk in a Chinese population. This retrospective cohort study was a secondary analysis of data from the DATADRYAD website, involving 211,172 non-diabetic individuals aged ≥ 20 years from the health screening program in China. Cox regression models were employed to evaluate hazard ratios (HRs) with 95% confidence interval (CI) of diabetes related to height. During an average 3.12-year follow-up, 4156 (1.97%) subjects reported developing diabetes. After adjusting for potential confounding factors, an inverse association of height with diabetes risk was observed among men and women [HR per 10 cm (95% CI), 0.78 (0.73-0.83) and 0.76 (0.68-0.86), respectively]. Moreover, subgroup analyses indicated the inverse association was only detected in individuals with aged < 70 years, fasting plasma glucose (FPG) < 6.1 mmol/L, and men with body mass index (BMI) < 28 kg/m2. In brief, height is inversely associated with diabetes risk in Chinese adults. Specifically, this association appears to be more pronounced in individuals with aged < 70 years, FPG < 6.1 mmol/L, and men with BMI < 28 kg/m2.

Effects of Intrauterine Growth Restriction (IUGR) on Growth and Body Composition Compared to Constitutionally Small Infants

(1) Intrauterine growth restriction (IUGR) is associated with multiple morbidities including growth restriction and impaired neurodevelopment. Small for gestational age (SGA) is defined as a birth weight <10th percentile, regardless of the etiology. The term is commonly used as a proxy for IUGR, but it may represent a healthy constitutionally small infant. Differentiating between IUGR and constitutionally small infants is essential for the nutritional management. (2) Infants born at <37 weeks of gestation between 2017 and 2022, who underwent body composition measurement (FFM: fat-free mass; FM: fat mass) at term-equivalent age, were included in this study. Infants with IUGR and constitutionally small infants (SGA) were compared to infants appropriate for gestational age (AGA). (3) A total of 300 infants (AGA: n = 249; IUGR: n = 40; SGA: n = 11) were analyzed. FFM (p < 0.001) and weight growth velocity (p = 0.022) were significantly lower in IUGR compared to AGA infants, but equal in SGA and AGA infants. FM was not significantly different between all groups. (4) The FFM Z-score was significantly lower in IUGR compared to AGA infants (p = 0.017). Being born constitutionally small compared to AGA had no impact on growth and body composition. These data showed that early aggressive nutritional management is essential in IUGR infants to avoid impaired growth and loss of FFM.

The Exon 3-Deleted Growth Hormone Receptor (d3GHR) Polymorphism-A Favorable Backdoor Mechanism for the GHR Function

Growth hormone (GH) is a peptide hormone that plays a crucial role in controlling growth, development, and lifespan. Molecular regulation of GH is accomplished via the GH receptor (GHR), which is the main factor influencing human development and is essential to optimal functioning of the GH/IGF-I axis. Two GHR isoforms have been studied, according to the presence (flGHR) or absence (d3GHR) of exon 3. The d3GHR isoform, which lacks exon 3 has recently been related to longevity; individuals carrying this isoform have higher receptor activity, improved signal transduction, and alterations in the treatment response and efficacy compared with those carrying the wild type (WT) isoform (flGHR). Further, studies performed in patients with acromegaly, Prader-Willi syndrome, Turner syndrome, small for gestational age (SGA), and growth hormone deficiency (GHD) suggested that the d3GHR isoform may have an impact on the relationship between GH and IGF-I levels, height, weight, BMI, and other variables. Other research, however, revealed inconsistent results, which might have been caused by confounding factors, including limited sample sizes and different experimental methods. In this review, we lay out the complexity of the GHR isoforms and provide an overview of the major pharmacogenetic research conducted on this ongoing and unresolved subject.

Ambient Air Pollution and All-Cause and Cause-Specific Mortality in an Analysis of Asian Cohorts

INTRODUCTION

Much of what is currently known about the adverse effects of ambient air pollution comes from studies conducted in high-income regions, with relatively low air pollution levels. The aim of the current project is to examine the relationship between exposure to ambient air pollution (as predicted from satellite-based models) and all-cause and cause-specific mortality in several Asian cohorts.

METHODS

Cohorts were recruited from the Asia Cohort Consortium (ACC). The geocoded residences of participants were assigned levels of ambient particulate material with aerodynamic diameter of 2.5 μm or less (PM2.5) and nitrogen dioxide (NO2) utilizing global satellite-derived models and assigned for the year of enrollment (or closest available year). The association between ambient exposure and mortality was established with Cox proportional hazard models, after adjustment for common confounders. Both single- and two-pollutant models were generated. Model robustness was evaluated, and hazard ratios were calculated for each cohort separately and combined via random effect meta-analysis for pooled risk estimates.

RESULTS

Six cohort studies from the ACC participated: the Community-based Cancer Screening Program (CBCSCP, Taiwan), the Golestan Cohort Study (Iran), the Health Effects for Arsenic Longitudinal Study (HEALS, Bangladesh), the Japan Public Health Center-based Prospective Study (JPHC), the Korean Multi-center Cancer Cohort Study (KMCC), and the Mumbai Cohort Study (MCS, India). The cohorts represented over 340,000 participants.

Mean exposures to PM2.5 ranged from 8 to 58 μg/m3. Mean exposures to NO2 ranged from 7 to 23 ppb. For PM2.5, a positive, borderline nonsignificant relationship was observed between PM2.5 and cardiovascular mortality. Other relationships with PM2.5 tended toward the null in meta-analysis. For NO2, an overall positive relationship was observed between exposure to NO2 and all cancers and lung cancer. A borderline association between NO2 and nonmalignant lung disease was also observed. The findings within individual cohorts remained consistent across a variety of subgroups and alternative analyses, including two-pollutant models.

CONCLUSIONS

In a pooled examination of cohort studies across Asia, ambient PM2.5 exposure appears to be associated with an increased risk of cardiovascular mortality and ambient NO2 exposure is associated with an increased cancer (and lung cancer) mortality. This project has shown that satellite-derived models of pollution can be used in examinations of mortality risk in areas with either incomplete or missing air pollution monitoring.

High-risk Growth Trajectory Related to Childhood Overweight/Obesity and Its Predictive Model at Birth

CONTEXT

Childhood obesity increases the risk of chronic disease in adulthood.

OBJECTIVE

To construct an early predictive model for a growth trajectory that is highly related to childhood overweight/obesity.

DESIGN

Prospective cohort study.

SETTINGS

Shanghai Birth Cohort (SBC) and US Collaborative Perinatal Project (CPP).

PARTICIPANTS

A total of 848 mother-child pairs in the SBC (2013-2016) and 22 691 pairs in the CPP (1959-1965) with 2- and 7-year follow-up, respectively.

MAIN OUTCOME MEASURES

A high-risk postnatal growth trajectory intimately associated with childhood overweight/obesity and its predictive model.

RESULTS

We demonstrated that the shifts of postnatal body mass index (BMI) percentile had been completed around 1 year of age and identified a high-risk growth trajectory that was closely related to overweight/obesity [odds ratio 6.5 (95% CI 5.9, 7.2)] at 7 years old. Children with this trajectory presented with a consistent BMI around the 85th percentile after the age of 1 year. It could be recognized early after birth using a predictive model with 4 metabolites (tyrosine, glycine, octenoylcarnitine, and stearoylcarnitine), combined with sex, birth weight, and maternal prepregnancy BMI. The model had an area under the receiver operating characteristic curve of 0.869 (95% CI 0.779, 0.932), a sensitivity of 83.3% (95% CI 51.6%, 97.9%), and a specificity of 81.1% (95% CI 70.3%, 89.3%) in the validation data set.

CONCLUSION

Children with postnatal high-risk growth trajectories were significantly associated with subsequent overweight/obesity at 7 years old. Metabolite profiles at birth combined with clinical measures were able to predict at-risk children before overweight/obesity occurrence.

Effects of household environmental exposure and ventilation in association with adverse birth outcomes: A prospective cohort study in rural China

Prenatal exposure to outdoor air pollution have been associated with birth outcomes. However, there is limited evidence on the adverse effects of household indoor air pollution worldwide, much less in rural areas of China. This study aimed to explore the associations of household environmental factors (primary cooking fuel, housing renovation, and home ventilation) with four adverse birth outcomes (preterm birth (PTB), small for gestational age (SGA), low birth weight (LBW), and term low birth weight (T-LBW)). We conducted a cohort study involving 10,324 pregnancies in women who delivered a live-born infant from 2015 to 2018 in Guangxi, China. Risk ratios and 95% confidence intervals (CI) were estimated with control for reproductive history, lifestyle, home environmental confounders, and other potential confounders. A total of 5.4% of the infants were PTB, 10.7% were SGA, 5.5% had LBW, and 3.0% had T-LBW. Household-use induction cookers as the primary cooking fuel during pregnancy was associated with SGA (RR = 1.31, 95% CI: 1.07-1.60), LBW (1.41, 1.09-1.82), and T-LBW(1.62, 1.16-2.26), as compared with household-use gas as the primary cooking fuel. Housing renovation within one year before pregnancy was associated with PTB (1.45, 1.06-1.98) and LBW (1.56, 1.17-2.09), while housing renovation during pregnancy was associated with a higher risk of SGA only in moderate home ventilation conditions (3.74, 1.69-8.28). Our findings suggested that household-use induction cookers as the primary cooking fuel increased the risks of SGA, LBW, and T-LBW. In addition, housing renovation within one year before pregnancy increased the risks of PTB and LBW. Proper home ventilation may reduce the effect on the association between housing renovation during pregnancy and SGA.

Long-term effectiveness of growth hormone therapy in children born small for gestational age: An analysis of LG growth study data

Purpose

Growth hormone (GH) treatment has been used to improve growth in short children who were born small for gestational age (SGA). The aim of this study was to investigate the long-term efficacy of GH treatment in these children.

Methods

Data from a multicenter observational clinical trial (ClinicalTrials.gov NCT01604395, LG growth study) were analyzed for growth outcome and prediction model in response to GH treatment. One hundred fifty-two children born SGA were included.

Results

The mean age of patients born SGA was 7.13 ± 2.59 years. Height standard deviation score (SDS) in patients born SGA increased from -2.55 ± 0.49 before starting treatment to -1.13 ± 0.76 after 3 years of GH treatment. Of the 152 patients with SGA, 48 who remained prepubertal during treatment used model development. The equation describing the predicted height velocity during 1st year of GH treatment is as follows: the predictive height velocity (cm) = 10.95 + [1.12 x Height SDS at initial treatment (score)] + [0.03 x GH dose (ug/kg/day)] + [0.30 x TH SDS at initial treatment (score)] + [0.05 x age (year)] + [0.15 x Weight SDS at initial treatment (score)] ± 1.51 cm.

Conclusions

GH treatment improved growth outcome in short children born SGA. We also developed a prediction model that is potentially useful in determining the optimal growth outcome for each child born SGA.

Trial registration

ClinicalTrials.gov Identifier: NCT01604395.

Individual and contextual socioeconomic status as effect modifier in the air pollution-birth outcome association

BACKGROUND

Several studies have examined whether air pollution is associated with adverse births outcomes, but it is not clear if socioeconomic status (SES) modifies this relationship.

OBJECTIVES

We investigated if maternal education and area-level socioeconomic status modified the relationship between ozone, nitrogen dioxide and particulate matter with aerodynamic diameter <10 μm (PM₁₀) on preterm births (PTB; gestational age <37 weeks) and term low birth weight (TLBW; weight < 2500 g on term deliveries).

METHODS

Analyses were based on almost 1 million singleton live births in São Paulo municipality between 2011 and 2016. The final sample included 979,306 births for PTB analysis and 888,133 for TLBW analysis. Exposure to PM₁₀, NO₂ and O₃ were based on date of birth and estimated for the entire gestation and for each trimester. Multilevel logistic regression models were conducted to examine the effect of air pollutants on both adverse birth outcomes and whether it was modified by individual and area-level SES.

RESULTS

In fully adjusted models, over the entire pregnancy, a 10 μg/m³ increase in O₃ and PM₁₀ was associated with increased chance of PTB (odds ratio; OR = 1.14 CI 1.13, 1.16 and 1.08 CI = 1.02, 1.15 respectively) and PM₁₀ with TLBW (OR = 1.08 CI 1.03, 1.14). Associations were modified by maternal educational and area-level SES for both outcomes. Mothers of lower education had an additional chance of PTB and TLBW due to PM₁₀ exposure (OR = 1.04 CI 1.04, 1.05 and 1.10 CI 1.08, 1.14 respectively), while mothers living in low SES areas have an additional chance for TLBW (OR = 1.05 CI 1.03, 1.06). Similar modification effects were found for O₃ exposure. Trimester specific associations were weaker but followed a similar pattern.

CONCLUSION

Socioeconomic status modifies the effect of air pollution on adverse birth outcomes. Results indicate that mothers with lower SES may be more susceptible to air pollution effects.

Lung function between 8 and 15 years of age in very preterm infants with fetal growth restriction

BACKGROUND

The impact of intrauterine growth restriction (IUGR) on lung function in very preterm children is largely unknown as current evidence is mainly based on studies in children born small for gestational age but not necessarily with IUGR.

METHODS

Spirometry, transfer factor of the lung for carbon monoxide (TLco), and lung clearance index (LCI) were cross-sectionally evaluated at 8.0-15.0 years of age in children born <32 weeks of gestation with IUGR (n = 28) and without IUGR (n = 67). Controls born at term (n = 67) were also included.

RESULTS

Very preterm children with IUGR had lower mean forced expired volume in the first second (FEV₁) z-score than those with normal fetal growth (∆ -0.66, 95% confidence interval (CI) -1.12, -0.19), but not significant differences in LCI (∆ +0.24, 95% CI -0.09, 0.56) and TLco z-score (∆ -0.11, 95% CI -0.44, 0.23). The frequency of bronchopulmonary dysplasia (BPD) in the two groups was, respectively, 43% and 10% (P = 0.003). IUGR was negatively associated with FEV₁ (B = -0.66; P = 0.004), but the association lost significance (P = 0.05) when adjusting for BPD.

CONCLUSIONS

IUGR has an impact on conducting airways function of very preterm children at school age, with part of this effect being mediated by BPD. Ventilation inhomogeneity and diffusing capacity, instead, were not affected.

IMPACT

IUGR does not necessarily imply a low birthweight for gestational age (and vice versa). While a low birthweight is associated with worse respiratory outcomes, the impact of IUGR on lung function in premature children is largely unknown. IUGR affects conducting airways function in school-age children born <32 weeks with IUGR, but not ventilation inhomogeneity and diffusing capacity. The impact of IUGR on FEV₁ seems mainly related to the higher risk of BPD in this group.

Midwives and protection of pregnant workers in Western Switzerland: Practices, difficulties and contributions

BACKGROUND

Switzerland's maternity protection legislation aims to protect the health of pregnant employees and their unborn children by regulating their potential occupational exposure to hazards and strenuous activities. This legislation provides a role for obstetricians, but not for midwives.

AIMS

Identify the practices of Switzerland's French-speaking midwives that favour the implementation of maternity protection legislation and reflect on the profession's role in supporting pregnant employees.

METHODS

356 midwives answered an online questionnaire. The analysis focuses on the 205 midwives who perform pregnancy consultations in their practice. Data were analysed in two stages using STATA software: 1) simple descriptive and correlational statistics and 2) hierarchical cluster analysis to identify typologies of practices by grouping similar responses.

FINDINGS

Despite having no officially defined role in Switzerland's maternity protection legislation, its midwives actively participate in protecting pregnant employees , especially those with more knowledge of the legislation, those with more years of experience and those practicing independently. The barriers that midwives face when trying to provide greater support for pregnant employees are linked significantly to their lack of knowledge about the legislation, a lack of recognition for their role in the current legislation and a lack of continuing education about the occupational health risks associated with pregnancy at work.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Their profession and specific practices give midwives privileged access to pregnant employees. Midwives' knowledge of the legislation, their awareness of the occupational risks and hazards facing pregnant employees and the conviction that their profession has the potential to make a difference could all be improved. The role of midwives should be-and deserves to be-formally and legally recognised and integrated into Switzerland's maternity protection legislation.

Gold nanoparticle biodistribution in pregnant mice following intravenous administration varies with gestational age

The use of nanoparticles (NPs) to deliver therapeutics to reproductive organs is an emerging approach to safely and effectively treat mothers and babies facing pregnancy complications. This study investigates the biodistribution of two different sized gold-based NPs in pregnant mice following systemic delivery as a function of gestational age. Poly(ethylene glycol)-coated 15 nm gold nanoparticles or 150 nm diameter silica core/gold nanoshells were intravenously administered to pregnant mice at gestational days (E)9.5 or 14.5. NP distribution was analyzed twenty-four hours later by inductively coupled plasma-mass spectrometry and silver staining of histological specimens. More NPs accumulated in placentas than embryos and delivery to these tissues was greater at E9.5 than E14.5. Neither NP type affected fetal weight or placental weight, indicating minimal short-term toxicity in early to mid-stage pregnancy. These findings warrant continued development of NPs as tools to deliver therapeutics to reproductive tissues safely.

Adulthood blood levels of hsa-miR-29b-3p associate with preterm birth and adult metabolic and cognitive health

Preterm birth (PTB) is associated with increased risk of type 2 diabetes and neurocognitive impairment later in life. We analyzed for the first time the associations of PTB with blood miRNA levels in adulthood. We also investigated the relationship of PTB associated miRNAs and adulthood phenotypes previously linked with premature birth. Blood MicroRNA profiling, genome-wide gene expression analysis, computer-based cognitive testing battery (CANTAB) and serum NMR metabolomics were performed for Young Finns Study subjects (aged 34-49 years, full-term n = 682, preterm n = 84). Preterm birth (vs. full-term) was associated with adulthood levels of hsa-miR-29b-3p in a fully adjusted regression model (p = 1.90 × 10-4, FDR = 0.046). The levels of hsa-miR-29b-3p were down-regulated in subjects with PTB with appropriate birthweight for gestational age (p = 0.002, fold change [FC] = - 1.20) and specifically in PTB subjects with small birthweight for gestational age (p = 0.095, FC = - 1.39) in comparison to individuals born full term. Hsa-miR-29b-3p levels correlated with the expressions of its target-mRNAs BCL11A and CS and the gene set analysis results indicated a target-mRNA driven association between hsa-miR-29b-3p levels and Alzheimer's disease, Parkinson's disease, Insulin signaling and Regulation of Actin Cytoskeleton pathway expression. The level of hsa-miR-29b-3p was directly associated with visual processing and sustained attention in CANTAB test and inversely associated with serum levels of VLDL subclass component and triglyceride levels. In conlcusion, adult blood levels of hsa-miR-29b-3p were lower in subjects born preterm. Hsa-miR-29b-3p associated with cognitive function and may be linked with adulthood morbidities in subjects born preterm, possibly through regulation of gene sets related to neurodegenerative diseases and insulin signaling as well as VLDL and triglyceride metabolism.

Effect of Omega-3 Supplementation in Pregnant Women with Obesity on Newborn Body Composition, Growth and Length of Gestation: A Randomized Controlled Pilot Study

Maternal obesity, a state of chronic low-grade metabolic inflammation, is a growing health burden associated with offspring adiposity, abnormal fetal growth and prematurity, which are all linked to adverse offspring cardiometabolic health. Higher intake of anti-inflammatory omega-3 (n-3) polyunsaturated fatty acids (PUFA) in pregnancy has been associated with lower adiposity, higher birthweight and longer gestation. However, the effects of n-3 supplementation specifically in pregnant women with overweight and obesity (OWOB) have not been explored. We conducted a pilot double-blind randomized controlled trial of 72 pregnant women with first trimester body mass index (BMI) ≥ 25 kg/m² to explore preliminary efficacy of n-3 supplementation. Participants were randomized to daily DHA plus EPA (2 g/d) or placebo (wheat germ oil) from 10-16 weeks gestation to delivery. Neonatal body composition, fetal growth and length of gestation were assessed. For the 48 dyads with outcome data, median (IQR) maternal BMI was 30.2 (28.2, 35.4) kg/m². In sex-adjusted analyses, n-3 supplementation was associated with higher neonatal fat-free mass (β: 218 g; 95% CI 49, 387) but not with % body fat or fat mass. Birthweight for gestational age z-score (-0.17 ± 0.67 vs. -0.61 ± 0.61 SD unit, p = 0.02) was higher, and gestation longer (40 (38.5, 40.1) vs. 39 (38, 39.4) weeks, p = 0.02), in the treatment vs. placebo group. Supplementation with n-3 PUFA in women with OWOB led to higher lean mass accrual at birth as well as improved fetal growth and longer gestation. Larger well-powered trials of n-3 PUFA supplementation specifically in pregnant women with OWOB should be conducted to confirm these findings and explore the long-term impact on offspring obesity and cardiometabolic health.

Ambient temperature and the risk of preterm birth: A national birth cohort study in the mainland China

BACKGROUND

Little is known about the effect of ambient temperature on preterm birth, especially for the trimester-specific effects.

OBJECTIVE

To evaluate whether exposure to relatively low or high temperature during pregnancy is associated with increasing risk of preterm birth or not.

METHOD

We analysed the data of a birth cohort with 1,281,859 singleton pregnancies during 2013-2014 and matched the home address of each pregnant women to the model based daily meteorological and air pollution data. Then we used the Cox proportional hazard regression models with random effect to estimate the non-linear associations between exposure to relatively low or high temperature at each trimester of pregnancy and the risk of preterm birth, after controlling for air pollution and individual-level covariates.

FINDING

The overall preterm birth rate was 8.1% (104,493 preterm births). Exposure to relatively low or high temperatures during the entire pregnancy significantly increase the risk of preterm birth, with hazard ratios (HRs) [95% confidence intervals (CIs)] of 1.03 (95%CI: 1.02, 1.04) for relatively low (9.1 ℃, the 5th percentile) temperature and 1.55 (95%CI: 1.48, 1.61) for relatively high (23.0 ℃, the 95th percentile) temperature in comparison with the thresholds (12.0 ℃). Pregnant women at the early pregnancy (the 1^st and 2^nd trimester) are more susceptible to high temperatures while pregnant women at the late pregnancy (the 3^rd trimester) are more susceptible to low temperatures.

CONCLUSION

These findings provide new evidence that exposure to relatively low or high temperatures during pregnancy increases the risk of preterm birth, which can serve as scientific evidence for prevention of preterm birth.

Design of nanomaterials for applications in maternal/fetal medicine

Pregnancy complications are commonplace and the challenges of treatment during pregnancy with few options available pose a risk to the health of both the mother and baby. Patients suffering from conditions such as preeclampsia, placenta accreta, and intrauterine growth restriction have few treatment options apart from emergency caesarean section. Fortunately, researchers are beginning to develop nanomedicine-based therapies that could be utilized to treat conditions affecting the mother, placenta, or fetus to improve the prognosis for mothers and their unborn children. This review summarizes the field's current understanding of nanoparticle biodistribution and therapeutic effect following systemic or vaginal administration and overviews the design parameters researchers should consider when developing nanomedicines for maternal/fetal health. It also describes safety considerations for nanomedicines to limit undesirable maternal or fetal side effects and discusses future work that should be performed to advance nanomedicine for maternal/fetal health. With additional development and implementation, the application of nanomedicine to treat pregnancy complications may mitigate the need for emergency caesarean sections and allow pregnancies to extend to term.

Maternal occupational exposure to carbonaceous nanoscale particles and small for gestational age and the evolution of head circumference in the French Longitudinal Study of Children - Elfe study

OBJECTIVES

To investigate the association between exposure to unintentionally emitted carbonaceous nanoscale particles (NPs) and small for gestational age (SGA), as well as head circumference (HC) at birth and at two years of age.

METHODS

Mothers from the French Longitudinal Study of Children (Elfe cohort) who worked during pregnancy were selected for our study. Data collected at birth and during follow-up (up to two years) were used. The probability and frequency of maternal occupational exposure to unintentionally emitted carbonaceous NPs was estimated using a job exposure matrix (MatPUF). Multivariate logistic regression, linear regression, and mixed models were applied to estimate any associations. Analyses were carried out depending on whether mothers stopped working during the first, second, or third trimester of pregnancy.

RESULTS

Maternal occupational exposure to unintentionally emitted carbonaceous NPs was associated with SGA in the overall study population by multivariate analysis (ORa = 1.80, 95% CI: 1.29, 2.46), as well as in sub-groups of mothers who stopped working during the second (ORa = 1.84, 95% CI: 1.13, 3.02) or third (ORa = 1.80, 95% CI: 1.10, 2.95) trimesters. There were no significant associations with HC at birth or two years of age.

CONCLUSIONS

We found a significant association between occupational exposure to carbonaceous NPs and SGA, with the effect depending on the period of exposure during pregnancy. These results should encourage further studies concerning the adverse effects of exposure to carbonaceous NPs on the development of offspring.

Growth status of children and adolescents born small for gestational age at full term in Korea: data from the KNHANES-V

Objectives Small for gestational age (SGA) status is known to show stunted growth and results in short stature in adults. The aim of this study was to describe the current short stature in subjects born SGA in Korea and to assess catch-up growth (CUG) or non-CUG. Methods We analyzed data from 3,524 subjects (1,831 male) aged 1-18 years who were born as full-term singletons and who participated in the Fifth Korean National Health and Nutrition Examination Survey (2010-2011). Results The prevalence of SGA was 13.4% (n=471). Subjects born SGA had fathers with shorter height, shorter mother's height, and mid-parental height than non-SGA subjects (p<0.05 for all). The odds ratios (ORs) for SGA birth of a short statured father and a short statured mother were 2.00 (95% CI; 1.15-3.47) and 2.11 (95% CI; 1.30-3.40), respectively. Among 471 SGA subjects, 28 subjects (5.9%) were non-CUG, which made up 36.4% of all subjects with short stature. The CUG subjects had a higher father's height, mother's height, mid-parental height, and current BMI (p<0.05 for all). The non-CUG subjects had a higher percentage of fathers being near-short stature (height<10th percentile; 33.3 vs. 12.7%; p=0.008) and mothers being near-short stature (39.3 vs. 13.9%; p<0.001). Conclusion Korean subjects born SGA had a higher risk of current short stature. This population-based nationwide survey also showed that both father's and mother's short stature are risk factors of not only SGA birth but also non-CUG in their children.

Maternal PM2.5 exposure triggers preterm birth: a cross-sectional study in Wuhan, China

Background

Most of the studies regarding air pollution and preterm birth (PTB) in highly polluted areas have estimated the exposure level based on fixed-site monitoring. However, exposure assessment methods relying on monitors have the potential to cause exposure misclassification due to a lack of spatial variation. In this study, we utilized a land use regression (LUR) model to assess individual exposure, and explored the association between PM_2.5 exposure during each time window and the risk of preterm birth in Wuhan city, China.

Methods

Information on 2101 singleton births, which were ≥ 20 weeks of gestation and born between November 1, 2013 and May 31, 2014; between January 1, 2015 and August 31, 2015, was obtained from the Obstetrics Department in one 3A hospital in Wuhan. Air quality index (AQI) data were accessed from the Wuhan Environmental Protection Bureau website. Individual exposure during pregnancy was assessed by LUR models and Kriging interpolation. Logistic regression analyses were conducted to determine the association between women exposure to PM_2.5 and the risk of different subtypes of PTB.

Results

During the study period, the average individual exposure concentration of PM_2.5 during the entire pregnancy was 84.54 μg/m³. A 10 μg/m³ increase of PM_2.5 exposure in the first trimester (OR: 1.169; 95% CI: 1.077, 1.262), the second trimester (OR: 1.056; 95% CI: 1.015, 1.097), the third trimester (OR: 1.052; 95% CI: 1.002, 1.101), and the entire pregnancy (OR: 1.263; 95% CI: 1.158, 1.368) was significantly associated with an increased risk of PTB. For the PTB subgroup, the hazard of PM_2.5 exposure during pregnancy was stronger for very preterm births (VPTB) than moderate preterm births (MPTB). The first trimester was the most susceptible exposure window. Moreover, women who had less than 9 years of education or who conceived during the cold season tended to be more susceptible to the PM_2.5 exposure during pregnancy.

Conclusions

Maternal exposure to PM_2.5 increased the risk of PTB, and this risk was stronger for VPTB than for MPTB, especially during the first trimester.

Korean reference for full-term birth length by sex: data from the 4th Korean National Health and Nutrition Examination Survey (KNHANES-IV; 2007-2009)

PURPOSE

The purpose of this study was to construct reference data for birth length of full-term and preterm Korean infants by sex and to define a sex-specific birth length cut-off to identify small for gestational age (SGA).

METHODS

Data were collected from the 4th Korean National Health and Nutrition Examination Survey (2007-2009), comprising 843 children with birth length data and birth history.

RESULTS

References for the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles of birth length and weight were created using singleton neonates of gestational age (GA) 36-37 weeks and 38-41 weeks by sex. The birth length cutoff value for SGA (&lt;10th percentile) was 48 cm in both male and female neonates, and the ≤3rd percentile cutoff was 47 cm in males and 46 cm in females born at a GA of 38-41 weeks.

CONCLUSION

New Korean reference data were created for birth length and differed from those of other ethnicities. Further research on short-term and long-term health outcomes of SGA infants based on the new reference data is needed.

Early markers of endocrinometabolic disease in newborns with delayed intrauterine growth

INTRODUCTION

The adjustments to malnutrition in growth restricted fetus (GRF) that lead to obesity, insulin resistance, diabetes and cardiovascular disease in adulthood are not well known. The most feasible explanation for this association is the hypothesis of catch up. Some studies postulate a greater influence of catch up growth than the low birth weight itself in developing metabolic and cardiovascular disease.

MATERIAL AND METHODS

This is a prospective cohort study of newborns with intrauterine growth restriction (defined as weight percentile at birth less than 10th) born during a one-year period. Clinical data of patients were recorded (gender, gestational age, data about breastfeeding and anthropometry during follow-up every 3 months). Some details of pregnancy and characteristics of the mother were also registered. Serum biochemical parameters (IGF-1, IGF-BP3, insulin, glucose, total cholesterol, HDL cholesterol, DLD cholesterol, triglycerides, HOMA) were collected at birth from cord blood, 9 and 12 months. Two main comparative groups were established: those GRF who made a catch-up growth (increase in weight Z score higher than 0,67) during the follow-up and those who did not get it.

RESULTS

126 GRF children were born in the study period. 125 accepted the inclusion in the study and 67 of them completed the full monitoring for a year; 47 of them made recovery growth and 20 did not. A significant difference between both groups was found in glucose in umbilical cord and triglycerides at 12 months: GRF children with catch up growth showed lower glucose levels (p = 0.03) and higher levels of triglycerides (p = 0.03). There were no statistically significant differences in the rest of laboratory parameters analyzed (IGF-1, IGF-BP3, insulin, glucose, total cholesterol, HDL cholesterol, DLD cholesterol, HOMA at 9 and 12 months or triglycerides at 9 months).

CONCLUSIONS

Those GRF with catch up growth during the first year of life have early changes in the triglycerides at the end of that period with higher levels than those GRF children without catch up growth. This finding could be useful to develop a tool for early detection of GRF children with higher metabolic risk in order to prevent future pathology.

The Insulin/IGF System in Mammalian Sexual Development and Reproduction

Persistent research over the past few decades has clearly established that the insulin-like family of growth factors, which is composed of insulin and insulin-like growth factors 1 (IGF1) and 2 (IGF2), plays essential roles in sexual development and reproduction of both males and females. Within the male and female reproductive organs, ligands of the family act in an autocrine/paracrine manner, in order to guide different aspects of gonadogenesis, sex determination, sex-specific development or reproductive performance. Although our knowledge has greatly improved over the last years, there are still several facets that remain to be deciphered. In this review, we first briefly outline the principles of sexual development and insulin/IGF signaling, and then present our current knowledge, both in rodents and humans, about the involvement of insulin/IGFs in sexual development and reproductive functions. We conclude by highlighting some interesting remarks and delineating certain unanswered questions that need to be addressed in future studies.

Relationships between greenness and low birth weight: Investigating the interaction and mediation effects of air pollution

BACKGROUND

Associations between residential greenness and improved birth weight have been increasingly reported, but underlying mechanisms and interactions with other environmental exposures are still unclear.

OBJECTIVES

To study the relationships between low birth weight (LBW, <2500 g), residential greenness, and the potential influence of air pollution in these relationships (interaction and mediation) in California, over the period 2001-2008.

METHODS

Residential greenness around maternal homes was characterized using the Normalized Difference Vegetation Index (NDVI). Complementary indicators of air pollution exposure reflected its main components. Birth weight and maternal characteristics were obtained from birth certificate records. In this case-cohort study, associations between greenness and LBW were investigated using multi-level Poisson regression with random effect at the hospital level. We investigated potential interaction of greenness and air pollutants on both additive and multiplicative scales. Mediation analyses were conducted to estimate the potential contribution of local variations in air pollutant concentrations associated with greenness on LBW risk.

RESULTS

In total 72,632 LBW cases were included. A reduction of LBW risk was associated with an increase in NDVI (adjusted risk ratio per inter-quartile range in NDVI: 0.963; 95% confidence interval: 0.947; 0.978). We observed no interaction between NDVI and air pollution on LBW risk. The estimated mediating effect of fine particulate matter in the impact of greenness on LBW was 12%.

CONCLUSION

This large study confirms that residential greenness is associated with a reduced risk of LBW and suggests that greenness might benefit to LBW partly through a local reduction in air pollution.

Intrauterine Growth Restriction: Postnatal Monitoring and Outcomes

Intrauterine growth restriction (IUGR) is an important cause of fetal, perinatal and neonatal morbidity and mortality. IUGR occurs because of multiple reasons. Neonates with IUGR experience acute problems in the perinatal and early neonatal period that can be life-threatening. The unfavorable uterine environment causing growth restriction results in programming that predisposes IUGR infants to long-term health issues such as poor physical growth, metabolic syndrome, cardiovascular disease, neurodevelopmental impairment and endocrine abnormalities, warranting careful monitoring. It is imperative to strike the balance between achieving optimal catch-up to promote normal development, while preventing the onset of cardiovascular and metabolic disorders in the long-term.

Association Between Vitamin D and Adrenal Parameters with Metabolic and Inflammatory Markers in Polycystic Ovary Syndrome

Vitamin D deficiency has been related with metabolic alterations in polycystic ovary syndrome (PCOS). As well, hyperactivation of adrenal axis can be programmed early in life and could be related later with PCOS development. Our aim was to establish the relationship between vitamin D and adrenal parameters with metabolic alterations and inflammation markers in PCOS. In 73 patients and 33 controls, 25-hydroxyvitamin D (25-OH-D), total and bioavailable testosterone (TT and bioT), androstenedione (A4), SHBG, cortisol, insulin, and C-reactive protein (hs-CRP) were determined; HOMA and lipid accumulation product (LAP) index were calculated. All parameters were higher in patients than in controls, except for SHBG and 25-OH-D which were lower. Binary regression analysis showed that differences in TT, bioT, A4, insulin and HOMA were independent of body mass index and waist circumference but SHBG, hs-CRP, LAP and 25-OH-D were related to body weight and fat distribution. Binary logistic regression analysis showed that cortisol and 25-OH-D could be associated to PCOS development. Correlations found between LAP and insulin, HOMA and hs-CRP confirm it is a good indicator of metabolic complications. Vitamin D and cortisol association to PCOS development justifies future research to understand the role of vitamin D in PCOS and analyze patient's perinatal history and its possible relationship with hyperactivation of adrenal axis in adult life.

Maternal occupational exposures to nanoscale particles and small for gestational age outcome in the French Longitudinal Study of Children

OBJECTIVES

To investigate the association between maternal occupational exposures to nanoscale particles (NPs) during pregnancy and small for gestational age (SGA).

METHODS

This study included 11,224 mothers and singleton birth pairs from the French Longitudinal Study of Children (ELFE cohort), which included infants born after 33 weeks of gestation or more in continental France in 2011. Mothers who did not work during pregnancy were excluded from the analyses. Maternal occupational exposures to NPs was estimated using a job-exposure matrix for the probability (>50%: occupationally exposed group, n = 569; 0%: occupationally non-exposed group, n = 9113; between these two thresholds: uncertain group, n = 1542) and frequency of exposure. Associations were estimated from multivariate logistic regression models for occupationally exposed vs occupationally unexposed groups in a first analysis, and with the frequency-weighted duration of work for the occupationally exposed group only in a second analysis.

RESULTS

Among working mothers, 5.1% were occupationally exposed to NPs. Maternal occupational exposures to NPs was associated with SGA (ORa = 1.63, 95% CI: 1.22, 2.18). The frequency-weighted duration of work for the occupationally exposed group (n = 569) was not associated with SGA (ORa = 1.02, 95% CI: 0.97, 1.08) in adjusted analyses.

CONCLUSIONS

These results, showing a significant association between occupational exposures to NPs and SGA, should encourage further studies to examine the adverse effect of NPs exposure on fetal development.

Effect of airborne particulate matter of 2.5 μm or less on preterm birth: A national birth cohort study in China

BACKGROUND

Most evidences regarding ambient PM_2.5 or PM₁₀ (particulate matter of median aerodynamic diameter ≤2.5 μm or ≤10 μm) and preterm birth (PTB) come from western countries which has relatively low PM pollution exposure, and the results are still inconsistent. This study aims to examine whether exposure to high concentrations of PM_2.5 or PM₁₀ was associated with PTB (<37 weeks) and near term birth (37-38 weeks).

METHOD

We established a birth cohort with 1,280,524 singleton pregnancies who delivered from Dec 1st, 2013 to Nov 30th, 2014 and matched their home address to PM_2.5 and PM₁₀ concentrations which were predicted with machine learning methods based satellite remote sensing, meteorological and land use information. Cox proportional hazard regression models were used to analyze the associations between PTB and exposure of PM_2.5 or PM₁₀, after controlling for individual level covariates.

RESULTS

Exposure to PM_2.5 or PM₁₀ during pregnancy increases the risk of PTB and near term birth [e.g., Hazard ratios: 1.09 (95% CI: 1.09, 1.10), 1.08 (95% CI: 1.07, 1.08), 1.01 (95% CI: 1.01, 1.02), and 1.09 (95% CI: 1.08, 1.10) for each 10 μg/m³ increase in PM_2.5 for the 1st, 2nd, 3rd trimester and over the entire pregnancy, respectively]. The effects appeared to be stronger among women who come from rural areas, worked as farmers, were overweight before conception, whose mate was smoking during pregnancy, and conceived in autumn.

CONCLUSION

This study provides clear evidence that exposure to PM_2.5 or PM₁₀ during pregnancy increases the risk of PTB and near term birth. Public policies regarding improvement of air quality would produce great health benefit by reducing the burden of preterm birth.

Predictive accuracy of cerebroplacental ratio for adverse perinatal and neurodevelopmental outcomes in suspected fetal growth restriction: systematic review and meta-analysis

OBJECTIVE

The cerebroplacental ratio (CPR) has been proposed for the routine surveillance of pregnancies with suspected fetal growth restriction (FGR), but the predictive performance of this test is unclear. The aim of this study was to determine the accuracy of CPR for predicting adverse perinatal and neurodevelopmental outcomes in suspected FGR.

METHODS

PubMed, EMBASE, CINAHL and Lilacs were searched from inception to 31 July 2017 for cohort or cross-sectional studies reporting on the accuracy of CPR for predicting adverse perinatal and/or neurodevelopmental outcomes in singleton pregnancies with FGR suspected antenatally based on sonographic parameters. Summary receiver-operating characteristics (ROC) curves, pooled sensitivities and specificities, and summary likelihood ratios (LRs) were generated.

RESULTS

Twenty-two studies (including 4301 women) met the inclusion criteria. Summary ROC curves showed that the best predictive accuracy of CPR was for perinatal death and the worst was for neonatal acidosis, with areas under the summary ROC curves of 0.83 and 0.57, respectively. The predictive accuracy of CPR was moderate to high for perinatal death (pooled sensitivity and specificity of 93% and 76%, respectively, and summary positive and negative LRs of 3.9 and 0.09, respectively) and low for composite of adverse perinatal outcomes, Cesarean section for non-reassuring fetal status, 5-min Apgar score < 7, admission to the neonatal intensive care unit, neonatal acidosis and neonatal morbidity, with summary positive and negative LRs ranging from 1.1 to 2.5 and 0.3 to 0.9, respectively. An abnormal CPR result had moderate accuracy for predicting small-for-gestational age at birth (summary positive LR of 7.4). CPR had a higher predictive accuracy in pregnancies with suspected early-onset FGR. No study provided data for assessing the predictive accuracy of CPR for adverse neurodevelopmental outcome.

CONCLUSION

CPR appears to be useful in predicting perinatal death in pregnancies with suspected FGR. Nevertheless, before incorporating CPR into the routine clinical management of suspected FGR, randomized controlled trials should assess whether the use of CPR reduces perinatal death or other adverse perinatal outcomes. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Effect of Dydrogesterone on the Outcome of Idiopathic Intrauterine Growth Restriction: A Double-blind Clinical Trial Study

Background:

The aim of this study was to evaluate the effect of dydrogesterone in the outcome of idiopathic intrauterine growth restriction (IUGR).

Materials and Methods:

It is a double-blind randomized control clinical trial study that was done in Shahid Beheshti hospital of Isfahan during 2015–2016. In this study, 89 pregnant women with idiopathic IUGR fetus were selected and randomly divided into two intervention and control groups. Intervention group was treated with dydrogesterone 10 mg every 12 h for 2 weeks, while the control group received conventional management and treatment of IUGR, which also has been performed in the intervention group.

Results:

After 2 weeks of intervention, fetal weight was significantly increased in dydrogesterone group as compared to control group (2053.15 vs. 1736.36 g, P = 0.001); furthermore, we observed significant differences in the term of fetal abdominal circumference between the groups (27.25 vs. 25.92 cm, P = 0.006). Middle cerebral artery resistance index (0.67 vs. 0.83, P < 0.001) and uterine artery (UA) resistance index (0.68 vs. 0.81, P < 0.001) were significantly decreased in dydrogesterone group as compared to control group.

Conclusions:

Our results showed that dydrogesterone reduces resistance index of uterine artery and middle cerebral and increased fetal weight, while no sign of toxicity was observed. Dydrogesterone supplementation would have the potentiality to become a simple and economic means to prevent IUGR.

Association of Long-term Exposure to Airborne Particulate Matter of 1 μm or Less With Preterm Birth in China

IMPORTANCE

Airborne particulate matter pollution has been associated with preterm birth (PTB) in some studies. However, most of these studies assessed only populations living near monitoring stations, and the association of airborne particulate matter having a median diameter of 1 μm or less (PM1) with PTB has not been studied.

OBJECTIVE

To evaluate whether PM1 concentrations are associated with the risk of PTB.

DESIGN, SETTING, AND PARTICIPANTS

This national cohort study used National Free Preconception Health Examination Project data collected in 324 of 344 prefecture-level cities from 30 provinces of mainland China. In total, 1 300 342 healthy singleton pregnancies were included from women who were in labor from December 1, 2013, through November 30, 2014. Data analysis was conducted between December 1, 2016, and April 1, 2017.

EXPOSURES

Predicted weekly PM1 concentration data collected using satellite remote sensing, meteorologic, and land use information matched with the home addresses of pregnant women.

MAIN OUTCOMES AND MEASURES

Preterm birth (<37 gestational weeks). Gestational age was assessed using the time since the first day of the last menstrual period. Cox proportional hazards regression analysis was used to examine the associations between trimester-specific PM1 concentrations and PTB after controlling for temperature, seasonality, spatial variation, and individual covariates.

RESULTS

Of the 1 300 342 singleton live births at the gestational age of 20 to 45 weeks included in this study, 104 585 (8.0%) were preterm. In fully adjusted models, a PM1 concentration increase of 10 μg/m3 over the entire pregnancy was significantly associated with increased risk of PTB (hazard ratio [HR], 1.09; 95% CI, 1.09-1.10), very PTB as defined as gestational age from 28 through 31 weeks (HR, 1.20; 95% CI, 1.18-1.23), and extremely PTB as defined as 20 through 27 weeks' gestation (HR, 1.29; 95% CI, 1.25-1.34). Pregnant women who were older (30-50 years) at conception (HR, 1.13; 95% CI, 1.11-1.14), were overweight before pregnancy (HR, 1.13; 95% CI, 1.11-1.15), had a rural household registration (HR, 1.09; 95% CI, 1.09-1.10), worked as farmers (HR, 1.10; 95% CI, 1.09-1.11), and conceived in autumn (HR, 1.48; 95% CI, 1.46-1.50) appeared to be more sensitive to PM1 exposure than their counterparts.

CONCLUSIONS AND RELEVANCE

Results from this national cohort study examining more than 1.3 million births indicated that exposure to PM1 air pollution was associated with an increased risk of PTB in China. These findings will provide evidence to inform future research studies, public health interventions, and environmental policies.

Maternal carriers of the ANXA5 M2 haplotype are exposed to a greater risk for placenta-mediated pregnancy complications

PURPOSE

Annexin A5 (ANXA5) is a protein abundantly expressed in normal placenta where it contributes to the healthy outcome of a pregnancy. Lower ANXA5 levels have been observed in M2/ANXA5 haplotype carrying chorion. Consequently, this study aimed to assess the potential association of M2 maternal carrier status with the risk of recurrent pregnancy loss (RPL), the timing of miscarriages, and other obstetric complications, for the first time in a population from Latin America.

METHODS

This study was designed as a prospective recruitment of RPL patients with post hoc analysis. The distribution of the M2/ANXA5 haplotype was compared between a group of 229 Argentine women with RPL and 100 parous controls, and was further analyzed in subgroups of patients stratified according to the timing of miscarriages and in relation to other obstetric complications.

RESULTS

No significant differences were found in the distribution of M2 haplotype among either RPL patients or the subgroups with embryonic, early fetal, or late fetal losses compared to parous controls. Notwithstanding, maternal M2/ANXA5 was found to be independently associated with a higher risk of suffering intrauterine growth restriction (IUGR) and/or preeclampsia (PE). Simultaneously, the presence of inherited and/or acquired thrombophilia also proved to be an independent risk factor for these.

CONCLUSIONS

The association found between the maternal carriage of the M2/ANXA5 haplotype and an elevated risk of IUGR and/or PE supports the hypothesis that carrier status of this haplotype and the consequently reduced placental ANXA5 expression might be responsible, at least partially, for the onset of these gestational vascular complications.

Maternal exposure to air pollutants during the first trimester and foetal growth in Japanese term infants

Evidence supporting an inverse association between maternal exposure to air pollutants and foetal growth has been accumulating. However, the findings from Asian populations are limited, and the question of critical windows of exposure remains unanswered. We examined whether maternal exposure to air pollutants, in particular exposure during the first trimester (an important period of placental development), was associated with foetal growth in Japanese term infants. From the Japan Perinatal Registry Network database, we received birth data for 29,177 term singleton births in western Japan (Kyushu-Okinawa Districts) between 2005 and 2010. Exposure was expressed in terms of average concentrations of air pollutants (ozone, suspended particulate matter, nitrogen dioxide, and sulphur dioxide), as measured at the nearest monitoring stations to the respective delivery hospitals of the pregnant women, during the entire pregnancy and each trimester. As proxy markers of foetal growth restriction, we used small for gestational age (SGA), and adverse birth weight (low birth weight in addition to SGA). For pollutant exposure during the entire pregnancy, we did not observe the association with SGA and adverse birth weight. In the single-trimester model for the first trimester, however, we found a positive association between ozone exposure, and SGA (odds ratio [OR] per 10 ppb increase = 1.07, 95% confidence interval [CI] = 1.01-1.12) and adverse birth weight (OR = 1.07; 95% CI = 1.01-1.14). This association persisted in the multi-trimester model, and no association for exposure during the second or third trimester was observed. Exposure to other pollutants during each trimester was not associated with these outcomes. In conclusion, maternal exposure to ozone during the first trimester was independently associated with an elevated risk of poor foetal growth.

Fetal Growth Restriction Induced by Transient Uterine Ischemia-Reperfusion: Differential Responses in Different Mouse Strains

We characterized fetal and placental growth and uterine and placental inflammation in pregnant C3H/HeOuJ and C57BL/6J mice (strains with different sensitivities to metabolic and circulatory pathologies), using different uterine ischemia/reperfusion (I/R) protocols, to establish and refine a murine model of I/R-induced fetal growth restriction (FGR). Pregnant C3H/HeOuJ mice on gestation day 15 were subjected to unilateral uterine I/R by (1) total blood flow restriction (TFR) by occlusion of the right ovarian and uterine arteries for 30 minutes, (2) partial flow restriction (PFR) by occlusion of only the right ovarian artery for 30 minutes, or (3) sham surgery. Pregnant C57BL/6J mice were treated the same, but on gestation day 14 and with TFR for only 5 minutes due to high sensitivity of C57BL/6J mice to I/R. Four days post-I/R, the animals were euthanized to determine fetal and placental weight and fetal loss and to assay placental myeloperoxidase (MPO) activity. In C3H/HeOuJ mice, TFR/30 minutes induced significantly ( P < .05) lower fetal and placental weights and higher placental MPO activity, compared to controls. The PFR/30 minutes produced the same effects except placental weights were not reduced. In contrast, in C57BL/6J mice, TFR for only 5 minutes was sufficient to induce FGR and increase fetal loss; while PFR/30 minutes lowered fetal but not placental weights and increased fetal loss but not placental MPO activity. In summary, we present the first published model of I/R-induced FGR in mice. We find that mice of different strains have differing sensitivities to uterine I/R, therefore differing I/R response mechanisms.

Ambient air pollution and low birth weight - are some women more vulnerable than others?

BACKGROUND AND OBJECTIVES

Ambient air pollution is controllable, and it is one of the greatest environmental threats to human health. Studies conducted worldwide have provided evidence that maternal exposure to ambient air pollution during pregnancy enhances the risk of low birth weight at term (TLBW, <2500g among infants born ≥37 completed weeks of gestation), a maker of intrauterine growth restriction (IUGR), and suggest that some subgroups of pregnant women who are smoking, of low or high body-mass index (BMI), low socioeconomic status (SES) or asthma are more vulnerable towards the effect of ambient air pollution. The aim of this commentary is to review the published literature on the association between ambient air pollution and TLBW regarding increased vulnerability for the above-mentioned subgroups.

RESULTS

Although more than fifty epidemiological studies have examined the associations between ambient air pollution and TLBW to date, we only identified six studies that examined the potential effect modification of the association between ambient air pollution and TLBW by the above listed maternal risk factors. Two studies assessed effect modification caused by smoking on the association between ambient air pollution and TLBW. The adjusted odds ratio (OR) for TLBW associated with exposure to ambient air pollution were in one study higher among women who smoked during pregnancy, as compared to the OR of non-smoking women, while in the other study the association was in the opposite direction. The association of ambient air pollution and TLBW were higher among women characterized by extreme BMI (two studies) and low SES compared to non-obese women or women of higher SES (four studies), respectively. Only one study reported the estimated effects among asthmatic and non-asthmatic women and no statistically significant effect modification was evident for the risk of TLBW associated with ambient air pollution.

CONCLUSION AND RECOMMENDATIONS

The current epidemiologic evidence is scarce, but suggests that pregnant women who are smoking, being underweight, overweight/obese or having lower SES are a vulnerable subpopulation when exposed to ambient air pollution, with and increased risk of having a child with TLBW. The limited evidence precludes for definitive conclusions and further studies are recommended.

Ponderal index at birth associates with later risk of gestational diabetes mellitus

PURPOSE

Low birth weight (BW) and low ponderal index (PI) are associated with increased risk of type 2 diabetes mellitus. This study has two purposes: first to investigate the influence of PI on the risk of gestational diabetes mellitus (GDM); second, to study the association between glucose metabolism and BW in women with previous GDM.

METHODS

GDM cohort: 185 women with GDM in 1978-1996, attending a follow-up study in 2000-2002. Control cohort: 1137 women from a population-based diabetes screening study (Inter99) in a neighbouring county in 1999-2001. BW and birth length were collected from the original midwifery records. BW and PI were stratified into tertiles for analysis.

RESULTS

PI in the lower tertiles was associated with an increased risk of GDM [odds ratio 1.59 (95% confidence interval 1.07-2.36, p = 0.021)]. Among women with previous GDM, the area under the curve (AUC) for plasma levels of glucose and insulin during an OGTT was highest for the lower tertiles of BW (for AUCglucose p = 0.048, for AUCinsulin p = 0.047 adjusted for age and BMI).

CONCLUSIONS

Lower PI is associated with increased risk of GDM. In women with previous GDM, lower BW is associated with a more severe impairment of glucose metabolism one to two decades after the pregnancy complicated by GDM.

Potential epigenetic biomarkers of obesity-related insulin resistance in human whole-blood

Obesity can increase the risk of complex metabolic diseases, including insulin resistance. Moreover, obesity can be caused by environmental and genetic factors. However, the epigenetic mechanisms of obesity are not well defined. Therefore, the identification of novel epigenetic biomarkers of obesity allows for a more complete understanding of the disease and its underlying insulin resistance. The aim of our study was to identify DNA methylation changes in whole-blood that were strongly associated with obesity and insulin resistance. Whole-blood was obtained from lean (n = 10; BMI = 23.6 ± 0.7 kg/m²) and obese (n = 10; BMI = 34.4 ± 1.3 kg/m²) participants in combination with euglycemic hyperinsulinemic clamps to assess insulin sensitivity. We performed reduced representation bisulfite sequencing on genomic DNA isolated from the blood. We identified 49 differentially methylated cytosines (DMCs; q < 0.05) that were altered in obese compared with lean participants. We identified 2 sites (Chr.21:46,957,981 and Chr.21:46,957,915) in the 5' untranslated region of solute carrier family 19 member 1 (SLC19A1) with decreased methylation in obese participants (lean 0.73 ± 0.11 vs. obese 0.09 ± 0.05; lean 0.68 ± 0.10 vs. obese 0.09 ± 0.05, respectively). These 2 DMCs identified by obesity were also significantly predicted by insulin sensitivity (r = 0.68, P = 0.003; r = 0.66; P = 0.004). In addition, we performed a differentially methylated region (DMR) analysis and demonstrated a decrease in methylation of Chr.21:46,957,915-46,958,001 in SLC19A1 of -34.9% (70.4% lean vs. 35.5% obese). The decrease in whole-blood SLC19A1 methylation in our obese participants was similar to the change observed in skeletal muscle (Chr.21:46,957,981, lean 0.70 ± 0.09 vs. obese 0.31 ± 0.11 and Chr.21:46,957,915, lean 0.72 ± 0.11 vs. obese 0.31 ± 0.13). Pyrosequencing analysis further demonstrated a decrease in methylation at Chr.21:46,957,915 in both whole-blood (lean 0.71 ± 0.10 vs. obese 0.18 ± 0.06) and skeletal muscle (lean 0.71 ± 0.10 vs. obese 0.30 ± 0.11). Our findings demonstrate a new potential epigenetic biomarker, SLC19A1, for obesity and its underlying insulin resistance.

Low birth weight and air pollution in California: Which sources and components drive the risk?

INTRODUCTION

Intrauterine growth restriction has been associated with exposure to air pollution, but there is a need to clarify which sources and components are most likely responsible. This study investigated the associations between low birth weight (LBW, <2500g) in term born infants (≥37 gestational weeks) and air pollution by source and composition in California, over the period 2001-2008.

METHODS

Complementary exposure models were used: an empirical Bayesian kriging model for the interpolation of ambient pollutant measurements, a source-oriented chemical transport model (using California emission inventories) that estimated fine and ultrafine particulate matter (PM2.5 and PM0.1, respectively) mass concentrations (4km×4km) by source and composition, a line-source roadway dispersion model at fine resolution, and traffic index estimates. Birth weight was obtained from California birth certificate records. A case-cohort design was used. Five controls per term LBW case were randomly selected (without covariate matching or stratification) from among term births. The resulting datasets were analyzed by logistic regression with a random effect by hospital, using generalized additive mixed models adjusted for race/ethnicity, education, maternal age and household income.

RESULTS

In total 72,632 singleton term LBW cases were included. Term LBW was positively and significantly associated with interpolated measurements of ozone but not total fine PM or nitrogen dioxide. No significant association was observed between term LBW and primary PM from all sources grouped together. A positive significant association was observed for secondary organic aerosols. Exposure to elemental carbon (EC), nitrates and ammonium were also positively and significantly associated with term LBW, but only for exposure during the third trimester of pregnancy. Significant positive associations were observed between term LBW risk and primary PM emitted by on-road gasoline and diesel or by commercial meat cooking sources. Primary PM from wood burning was inversely associated with term LBW. Significant positive associations were also observed between term LBW and ultrafine particle numbers modeled with the line-source roadway dispersion model, traffic density and proximity to roadways.

DISCUSSION

This large study based on complementary exposure metrics suggests that not only primary pollution sources (traffic and commercial meat cooking) but also EC and secondary pollutants are risk factors for term LBW.

Ambient air pollution and adverse birth outcomes: Differences by maternal comorbidities

BACKGROUND

Prenatal exposure to ambient air pollution has been associated with adverse birth outcomes, but the potential modifying effect of maternal comorbidities remains understudied. Our objective was to investigate whether associations between prenatal air pollution exposures and birth outcomes differ by maternal comorbidities.

METHODS

A total of 818,400 singleton live births were identified in the province of Ontario, Canada from 2005 to 2012. We assigned exposures to fine particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone (O3) to maternal residences during pregnancy. We evaluated potential effect modification by maternal comorbidities (i.e. asthma, hypertension, pre-existing diabetes mellitus, heart disease, gestational diabetes and preeclampsia) on the associations between prenatal air pollution and preterm birth, term low birth weight and small for gestational age.

RESULTS

Interquartile range (IQR) increases in PM2.5 (2μg/m(3)), NO2 (9ppb) and O3 (5ppb) over the entire pregnancy were associated with a 4% (95% CI: 2.4-5.6%), 8.4% (95% CI: 5.5-10.3%) and 2% (95% CI: 0.5-4.1%) increase in the odds of preterm birth, respectively. Increases of 10.6% (95% CI: 0.2-2.1%) and 23.8% (95% CI: 5.5-44.8%) in the odds of preterm birth were observed among women with pre-existing diabetes while the increases were of 3.8% (95% CI: 2.2-5.4%) and 6.5% (95% CI: 3.7-8.4%) among women without this condition for pregnancy exposure to PM2.5 and NO2, respectively (Pint<0.01). The increase in the odds of preterm birth for exposure to PM2.5 during pregnancy was higher among women with preeclampsia (8.3%, 95% CI: 0.8-16.4%) than among women without (3.6%, 95% CI: 1.8-5.3%) (Pint=0.04). A stronger increase in the odds of preterm birth was found for exposure to O3 during pregnancy among asthmatic women (12.0%, 95% CI: 3.5-21.1%) compared to non-asthmatic women (2.0%, 95% CI: 0.1-3.5%) (Pint<0.01). We did not find statistically significant effect modification for the other outcomes investigated.

CONCLUSIONS

Findings of this study suggest that associations of ambient air pollution with preterm birth are stronger among women with pre-existing diabetes, asthma, and preeclampsia.

The promoter methylomes of monochorionic twin placentas reveal intrauterine growth restriction-specific variations in the methylation patterns

Intrauterine growth restriction (IUGR) affects the foetus and has a number of pathological consequences throughout life. Recent work has indicated that variations in DNA methylation might cause placental dysfunction, which may be associated with adverse pregnancy complications. Here, we investigated the promoter methylomes of placental shares from seven monochorionic (MC) twins with selective intrauterine growth restriction (sIUGR) using the healthy twin as an ideal control. Our work demonstrated that the IUGR placental shares harboured a distinct DNA hypomethylation pattern and that the methylation variations preferentially occurred in CpG island shores or non-CpG island promoters. The differentially methylated promoters could significantly separate the IUGR placental shares from the healthy ones. Ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC‐MS/MS) further confirmed the genome‐wide DNA hypomethylation and the lower level of hydroxymethylation statuses in the IUGR placental shares. The methylation variations of the LRAT and SLC19A1 promoters, which are involved in vitamin A metabolism and folate transportation, respectively, and the EFS promoter were further validated in an additional 12 pairs of MC twins with sIUGR. Although the expressions of LRAT, SLC19A1 and EFS were not affected, we still speculated that DNA methylation and hydroxymethylation might serve a functional role during in utero foetal development.

Endothelin Receptor A Antagonism and Fetal Growth in Endothelial Nitric Oxide Synthase Gene Knockout Maternal and Fetal Mice

Fetal growth restriction (FGR) is commonly associated with perinatal morbidity and mortality. Nitric oxide (NO) deficiency increases endothelin-1 (ET-1) production, and this increased ET-1 may contribute to the pathophysiology of NO deficiency-induced FGR. Using an endothelial NO synthase knockout mouse model of FGR, we sought to determine (a) the relative importance of maternal versus conceptus (fetal and placental) NO deficiency and (b) the contribution of ET-1 to the pathogenesis of FGR in this model. Fetal growth restriction occurred both with NO-deficient conceptuses in the setting of maternal NO production and with maternal NO deficiency in the setting of NO-producing conceptuses. Placental ET-1 expression was increased in NO-deficient dams, ET receptor A (ETA) production increased in endothelial nitric oxide synthase(+/-) placentas, and antagonism of ETA prevented FGR. These results demonstrate that both maternal and conceptus NO deficiency can contribute to FGR and suggest a role for ETA antagonists as therapeutic agents in FGR.

Adverse Reproductive Health Outcomes and Exposure to Gaseous and Particulate-Matter Air Pollution in Pregnant Women

Introduction

There is growing epidemiologic evidence of associations between maternal exposure to ambient air pollution and adverse birth outcomes, such as preterm birth (PTB). Recently, a few studies have also reported that exposure to ambient air pollution may also increase the risk of some common pregnancy complications, such as preeclampsia and gestational diabetes mellitus (GDM). Research findings, however, have been mixed. These inconsistent results could reflect genuine differences in the study populations, the study locations, the specific pollutants considered, the designs of the study, its methods of analysis, or random variation. Dr. Jun Wu of the University of California– Irvine, a recipient of HEI’s Walter A. Rosenblith New Investigator Award, and colleagues have examined the association between air pollution and adverse birth and pregnancy outcomes in California women. In addition, they examined the effect modification by socioeconomic status (SES) and other factors.

Approach

A retrospective nested case–control study was conducted using birth certificate data from about 4.4 million birth records in California from 2001 to 2008. Wu and colleagues analyzed data on low birth weight (LBW) at term (infants born between 37 and 43 weeks of gestation and weighing less than 2500 g), PTB (infants born before 37 weeks of gestation), and preeclampsia (including eclampsia) of the mother during the pregnancy. In addition, they obtained data on GDM for the years 2006– 2008. In the analyses, all outcomes were included as binary variables. Maternal residential addresses at the time of delivery were geocoded, and a large suite of air pollution exposure metrics was considered, such as (1) regulatory monitoring data on concentrations of criteria pollutants NO2, PM2.5 (particulate matter ≤ 2.5 μm in aerodynamic diameter), and ozone (O3) estimated by empirical Bayesian kriging; (2) concentrations of primary and secondary PM2.5 and PM0.1 components and sources estimated by the University of California–Davis Chemical Transport Model; (3) traffic-related ultrafine particles and concentrations of carbon monoxide (CO) and nitrogen oxides (NOx) estimated by a modified CALINE4 air pollution dispersion model; and (4) proximity to busy roads, road length, and traffic density calculated for different buffer sizes using geographic information system tools. In total, 50 different exposure metrics were available for the analyses. The exposure of primary interest was the mean of the entire pregnancy period for each mother. For the health analyses, controls were randomly selected from the source population. PTB controls were matched on conception year. Term LBW, preeclampsia, and GDM were analyzed using generalized additive mixed models with inclusion of a random effect per hospital. PTB analyses were conducted using conditional logistic regression, with no adjustment for hospital. The main results— adjusted for race and education as categorical variables and adjusted for maternal age and median household income at the census-block level—were derived from single-pollutant models.

Main results and interpretation

In its independent review of the study, the HEI Health Review Committee concluded that Wu and colleagues had conducted a comprehensive nested case–control study of air pollution and adverse birth and pregnancy outcomes. The very large data set and the extensive exposure assessment were strengths of the study. The study documented associations between increases in various air pollution metrics and increased risks of PTB, whereas the evidence was weaker overall for term LBW; in addition, decreases in many air pollution metrics were associated with an increased risk of preeclampsia and GDM, an unexpected result. The investigators suggested that underreporting in the registry data, especially in lower-SES groups, might have caused the many negative associations found for preeclampsia and GDM. In addition, poor geocoding was listed as a potential explanation, affecting in particular the results that were based on measures of proximity to busy roads and traffic density in the smallest buffer size (50 m). However, those issues were not fully explored. In general, the Committee thought that the analysis of road traffic indicators in the 50 m buffer was hampered by the lack of contrast and that the results are therefore difficult to interpret. Some other issues with the analytical approaches should be considered when interpreting the results. Only a subset of controls was used, to reduce computational demands. Hence, some models did not converge, especially in the subgroup analyses. Most of the results in the report were based on analyses using single-pollutant models, which is a reasonable approach but ignores that people are exposed to complex mixtures of pollutants. The Committee believed that the few two-pollutant models that were run provided important insights: these models showed the strongest association for PM2.5 mass, whereas components and source-specific positive associations largely disappeared after adjusting for PM2.5 mass. This study adds to the ongoing debate about whether some particle components and sources are of greater public health concern than others.

Ambient air pollution and preterm birth: A prospective birth cohort study in Wuhan, China

IMPORTANCE

Although studies in western countries suggest that ambient air pollution is positively associated with adverse pregnancy outcomes, the upper levels of pollutant exposures have been relatively low, thus eroding confidence in the conclusions. Meanwhile, in Asia, where upper levels of exposure have been greater, there have been limited studies of the association between air pollution and adverse pregnancy outcomes.

OBJECTIVE

The primary objective was to evaluate whether high levels of pollution, including particulate matter pollution with a mass median aerodynamic diameter of less than 2.5 μm (PM2.5) and 10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO) are related to increased occurrence of preterm birth (PTB).

METHODS

We conducted a population-based study in Wuhan, China in a cohort of 95,911 live births during a two-year period from 2011 to 2013. The exposure was estimated based on daily mean concentrations of pollutants estimated using the pollutants' measurements from the nine closest monitors. Logistic regressions were performed to determine the relationships between exposure to each of the pollutants during different pregnancy periods and PTB while controlling for key covariates.

RESULTS

We found 3% (OR=1.03; 95% CI: 1.02, 1.05), 2% (OR=1.02; 95% CI: 1.02, 1.03), 15% (OR=1.15; 95% CI: 1.11, 1.19), and 5% (OR=1.05; 95% CI: 1.02, 1.07) increases in risk of PTB with each 5-μg/m(3) increase in PM2.5 and PM10 concentrations, 100-μg/m(3) increase in CO concentrations, and 10-μg/m(3) increase in O3 concentrations, respectively. There was negligible evidence for associations for SO2 and NO2. The effects from two-pollutant models were similar to the estimated effects from single pollutant models. No critical exposure windows were identified consistently: the strongest effect for PTB was found in the second trimester for PM2.5, PM10, and CO, but for SO2 it was in the first trimester, second month, and third month. For NO2 it was in the first trimester and second month, and for O3, the third trimester.

CONCLUSION

Findings reveal an association between air pollutants and PTB. However, more toxicological studies and prospective cohort studies with improved exposure assessments are needed to establish causality related to specific pollutants.

Variants in Vitamin D Binding Protein Gene Are Associated With Gestational Diabetes Mellitus

To investigate whether single nucleotide polymorphisms (SNPs) within 4 representative genes (VDR, GC, CYP2R1, and CYP24A1) encoding the core proteins involved in vitamin D production, degradation, and ligand-dependent signaling pathway are associated with gestational diabetes mellitus (GDM) in a Chinese population. A total of 1494 pregnant Han Chinese women (692 women with GDM and 802 women with normal glucose served as controls) were recruited through a 2-step approach. Participants were further divided into 2 groups according to body mass index before gestation (pre-BMI) (25 kg/m2). Nine SNPs (rs3733359, rs2282679, and rs16847024 in GC, rs2060793 and rs10741657 in CYP2R1, rs2248359 and rs6013897 in CYP24A1, rs11574143 and rs739837 in VDR) were genotyped using TaqMan allelic discrimination assays. The relationships between genotypes/alleles of a single locus as well as haplotypes of each gene and GDM were analyzed. We did not observe a significant difference in genotype frequency of each SNP between cases and controls. However, in the obese subgroup (pre-BMI ≥ 25 kg/m2), the risk allele-A of rs3733359 showed an association with increased risk of GDM (OR = 1.739, 95% CI = 1.066-2.837, P = 0.027). The GG-haplotype frequency of rs3733359 and rs2282679 in GC was modestly lower in the GDM group (OR = 0.848, 95% CI = 0.719-0.999, P = 0.048). Rs2060793 and rs10741657 were associated with insulin area under the curve (P = 0.028, P = 0.042, respectively), while rs739837 and rs6013897 demonstrated a correlation with fasting glucose (P = 0.019, P = 0.049, respectively). Additionally, rs2248359 displayed an association with leukocyte counts (B = 0.063 P = 0.033) and rs16847024 was related to high-sensitivity C-reactive protein levels (B = 0.086, P = 0.005). Our results indicate an association between GC variants and GDM, as well as a relation between a subset of loci in CYP2R1, CYP24A1, and VDR and clinical parameters related to GDM. Our findings may provide information for identifying biomarkers for early risk prediction of GDM and the pathways involved in disease progression.

The ProVIDe study: the impact of protein intravenous nutrition on development in extremely low birthweight babies

BACKGROUND

Preterm birth and very small size at birth have long-term effects on neurodevelopment and growth. A relatively small percentage of extremely low birthweight babies suffer from severe neurological disability; however, up to 50% experience some neurodevelopmental or learning disability in childhood. Current international consensus is that increased protein intake in the neonatal period improves both neurodevelopment and growth, but the quantum of protein required is not known. This trial aims to assess whether providing an extra 1 to 2 g.kg(-1).d(-1) protein in the first 5 days after birth will improve neurodevelopmental outcomes and growth in extremely low birthweight babies.

METHODS/DESIGN

The ProVIDe study is a multicentre, two-arm, double-blind, parallel, randomised, controlled trial. In addition to standard intravenous nutrition, 430 babies with a birthweight of less than 1000 g who have an umbilical arterial line in situ will be randomised in 1:1 ratio to receive either an amino acid solution (TrophAmine®) or placebo (saline) administered through the umbilical arterial catheter for the first 5 days. Exclusion criteria are admission to neonatal intensive care more than 24 h after birth; multiple births of more than 2 babies; known chromosomal or genetic abnormality, or congenital disorder affecting growth; inborn error of metabolism, and in danger of imminent death.

PRIMARY OUTCOME

Survival free from neurodevelopmental disability at 2 years' corrected age, where neurodevelopmental disability is defined as cerebral palsy, blindness, deafness, developmental delay (standardised score more than 1 SD below the mean on the cognitive, language or motor subscales of the Bayley Scales of Infant Development Edition 3), or Gross Motor Function Classification System score ≥ 1.

SECONDARY OUTCOMES

Growth, from birth to 36 weeks' corrected gestational age, at neonatal intensive care discharge and at 2 years' corrected age; body composition at 36 to 42 weeks' corrected postmenstrual age and at 2 years' corrected age; neonatal morbidity, including length of stay; nutritional intake.

DISCUSSION

This trial will provide the first direct evidence of the effects of giving preterm babies a higher intake of intravenous protein in the first week after birth on neurodevelopmental outcomes at 2 years corrected age.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12612001084875.

Height at Late Adolescence and Incident Diabetes among Young Men

BACKGROUND

Short stature was suggested as a risk factor for diabetes onset among middle age individuals, but whether this is the case among young adults is unclear. Our goal was to assess the association between height and incident diabetes among young men.

METHODS AND FINDINGS

Incident diabetes was assessed among 32,055 men with no history of diabetes, from the prospectively followed young adults of the MELANY cohort. Height was measured at two time points; at adolescence (mean age 17.4±0.3 years) and grouped according to the US-CDC percentiles and at young adulthood (mean age 31.0±5.6 years). Cox proportional hazards models were applied. There were 702 new cases of diabetes during a mean follow-up of 6.3±4.3 years. There was a significant increase in the crude diabetes incidence rate with decreasing adolescent height percentile, from 4.23 cases/104 person-years in the <10th percentile group to 2.44 cases/104 person-years in the 75th≤ percentile group. These results persisted when clinical and biochemical diabetes risk factors were included in multivariable models. Compared to the 75th≤ percentile group, height below the 10th percentile was associated with a hazard ratio (HR) of 1.64 (95%CI 1.09-2.46, p = 0.017) for incident diabetes after adjustment for age, body mass index (BMI), fasting plasma glucose, HDL-cholesterol and triglyceride levels, white blood cells count, socioeconomic status, country of origin, family history of diabetes, sleep quality and physical activity. At age 30 years, each 1-cm decrement in adult height was associated with a 2.5% increase in diabetes adjusted risk (HR 1.025, 95%CI 1.01-1.04, p = 0.001).

CONCLUSIONS

Shorter height at late adolescence or young adulthood was associated with an increased risk of incident diabetes among young men, independent of BMI and other diabetes risk factors.