Association of prenatal multiple metal exposures with child neurodevelopment at 3 years of age: A prospective birth cohort study.

Prenatal exposures to toxic metals and trace elements have been linked to childhood neurodevelopment. However, existing evidence remains inconclusive, and further research is needed to investigate the mixture effects of multiple metal exposures on childhood neurodevelopment. We aimed to examine the associations between prenatal exposure to specific metals and metal mixtures and neurodevelopment in children. In this prospective cohort study, we used the multivariable linear regressions and the robust modified Poisson regressions to explore the associations of prenatal exposure to 25 specific metals with neurodevelopment among children at 3 years of age in 854 mother-child pairs from the Jiangsu Birth Cohort (JBC) Study. The Bayesian kernel machine regression (BKMR) was employed to assess the joint effects of multiple metals on neurodevelopment. Prenatal manganese (Mn) exposure was negatively associated with the risk of non-optimal cognition development of children, while vanadium (V), copper (Cu), zinc (Zn), antimony (Sb), cerium (Ce) and uranium (U) exposures were positively associated with the risk of non-optimal gross motor development. BKMR identified an interaction effect between Sb and Ce on non-optimal gross motor development. Additionally, an element risk score (ERS), representing the mixture effect of multiple metal exposures including V, Cu, Zn, Sb, Ce and U was constructed based on weights from a Poisson regression model. Children with ERS in the highest tertile had higher probability of non-optimal gross motor development (RR = 2.37, 95 % CI: 1.15, 4.86) versus those at the lowest tertile. Notably, Sb [conditional-posterior inclusion probabilities (cPIP) = 0.511] and U (cPIP = 0.386) mainly contributed to the increased risk of non-optimal gross motor development. The findings highlight the importance of paying attention to the joint effects of multiple metals on children's neurodevelopment. The ERS score may serve as an indicator of comprehensive metal exposure risk for children's neurodevelopment.

Assisted reproductive technology and neurodevelopment in children at 1 year of age: a longitudinal birth cohort study.

BACKGROUND: With remarkable advancements in assisted reproductive technology (ART), the number of ART-conceived children continues to increase. Despite increased research investigating the outcomes of ART children, evidence on neurodevelopment remains controversial. OBJECTIVE: The aim of this study was to investigate the association between ART use and neurodevelopment in children at 1 year of age and to determine whether the characteristics of parental infertility and specific ART procedures affect neurodevelopment in children. STUDY DESIGN: The Jiangsu Birth Cohort enrolled couples who received ART treatment and who conceived spontaneously (2014-2020) in Jiangsu Province, China. In this study, we included 3531 pregnancies with 3840 cohort children who completed neurodevelopment assessment at 1 year of age, including 1906 infants conceived by ART (including 621 twins). Poisson regressions were fitted to estimate unadjusted and adjusted risk ratios (RRs) and 95% confidence intervals (CIs) for ART use with neurodevelopmental outcomes (cognition, receptive communication, expressive communication, fine motor, and gross motor) in children. RESULTS: Among singletons, ART use was associated with a 24% to 34% decrease in the risk for noncompetent development in 3 domains (cognition, adjusted RR, 0.66; 95% CI, 0.53-0.82; receptive communication, 0.76; 0.64-0.91; expressive communication, 0.69; 0.51-0.93) after adjustment for conventional covariates. However, an inverse association was observed in the gross motor domain, with ART singletons having a greater risk of being noncompetent in gross motor development than their non-ART counterparts (adjusted RR, 1.41; 95% CI, 1.11-1.79). Compared with singletons, twins resulting from ART treatment demonstrated compromised neurodevelopment in several domains. Furthermore, we continued to observe that the transfer of 'poor' quality embryos was associated with greater risks for noncompetent development in receptive communication (adjusted RR, 1.50; 95% CI, 1.05-2.14) and gross motor domains (1.55; 1.02-2.36) among ART singletons. CONCLUSION: These results generally provide reassuring evidence among singletons born after ART in the cognition, communication, and fine motor domains, but drawn attention to their gross motor development. The quality of transferred embryos in ART treatment might be associated with offspring neurodevelopment; however, the potential associations warrant further validation in independent studies, and the clinical significance needs careful interpretation.

Maternal Dietary Cholesterol and Egg Intake during Pregnancy and Large-for-Gestational-Age Infants: A Prospective Cohort Study.

BACKGROUND: Cholesterol plays a vital role in fetal growth and development during pregnancy. There remains controversy over whether pregnant females should limit their cholesterol intake. OBJECTIVES: The objective of this study was to investigate the association between maternal dietary cholesterol intake during pregnancy and infant birth weight in a Chinese prospective cohort study. METHODS: A total of 4146 mother-child pairs were included based on the Jiangsu Birth Cohort study. Maternal dietary information was assessed with a semiquantitative food-frequency questionnaire. Birth weight z-scores and large-for-gestational-age (LGA) infants were converted by the INTERGROWTH-21st neonatal weight-for-gestational-age standard. Poisson regression and generalized estimating equations were employed to examine the relationships between LGA and maternal dietary cholesterol across the entire pregnancy and trimester-specific cholesterol intake, respectively. RESULTS: The median intake of maternal total dietary cholesterol during the entire pregnancy was 671.06 mg/d, with eggs being the main source. Maternal total dietary cholesterol and egg-sourced cholesterol were associated with an increase in birth weight z-score, with per standard deviation increase in maternal total and egg-sourced dietary cholesterol being associated with an increase of 0.16 [95% confidence interval (CI): 0.07, 0.25] and 0.06 (95% CI: 0.03, 0.09) in birth weight z-score, respectively. Egg-derived cholesterol intake in the first and third trimesters was positively linked to LGA, with an adjusted relative risk of 1.11 (95% CI: 1.04, 1.18) and 1.09 (95% CI: 1.00, 1.18). Compared with mothers consuming ≤7 eggs/wk in the third trimester, the adjusted relative risk for having an LGA newborn was 1.37 (95% CI: 1.09, 1.72) for consuming 8-10 eggs/wk and 1.45 (95% CI: 1.12, 1.86) for consuming >10 eggs/wk (P-trend = 0.015). CONCLUSIONS: Maternal total dietary cholesterol intake, as well as consuming over 7 eggs/wk during pregnancy, displayed significant positive relationships with the incidence of LGA, suggesting that mothers should avoid excessive cholesterol intake during pregnancy to prevent adverse birth outcomes.

Phthalate and DINCH exposure and ovarian reserve markers among women seeking infertility care.

Phthalate exposure can adversely impact ovarian reserve, yet investigation on the influence of its alternative substance, the non-phthalate plasticizer diisononyl-cyclohexane-1,2-dicarboxylate (DINCH), on ovarian reserve is very sparce. We aimed to investigate the associations of phthalate and DINCH exposure as well as their combined mixture with ovarian reserve. This present study included 657 women seeking infertility care in Jiangsu, China (2015-2018). Urine samples during enrollment prior to infertility treatment were analyzed using high-performance liquid chromatography-isotope dilution tandem mass spectrometry (UPLC-MS/MS) to quantify 17 phthalate metabolites and 3 DINCH metabolites. Multivariate linear regression models, Poisson regression models and weighted quantile sum (WQS) regression were performed to access the associations of 17 urinary phthalate metabolites and 3 DINCH metabolites with ovarian reserve markers, including antral follicle count (AFC), anti-Mullerian hormone (AMH), and follicle-stimulating hormone (FSH). We found that the most conventional phthalates metabolites (DMP, DnBP, DiBP, DBP and DEHP) were inversely associated with AFC, and the DINCH metabolites were positively associated with serum FSH levels. The WQS index of phthalate and DINCH mixtures was inversely associated with AFC (% change = -8.56, 95 % CI: -12.63, -4.31) and positively associated with FSH levels (% change =7.71, 95 % CI: 0.21, 15.78). Our findings suggest that exposure to environmental levels of phthalate and DINCH mixtures is inversely associated with ovarian reserve.

Effect of thyroid function on offspring neurodevelopment in people receiving ART therapy: a prospective cohort study.

CONTEXT: Adequate maternal thyroid hormone is vital for fetal neurodevelopment. Abnormal thyroid function can cause developmental defects in offspring from spontaneous pregnancies; however, research in assisted reproduction is lacking. OBJECTIVES: To investigate the association between thyroid disorders and offspring neurodevelopment from assisted reproduction. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: In this prospective and longitudinal birth cohort study (Jiangsu, China), we included 729 women who had their thyroid function tested before ART cycle and delivered liveborn babies between November 2015 and June 2020. MAIN OUTCOME MEASURES: Maternal thyroid function was assessed by measuring thyroid antibodies, free thyroxine, and serum thyroid-stimulating hormone. The third edition Bayley Scales of Infant and Toddler Development screening test (Bayley-III screening test) is used to assess the infant's neurodevelopment. RESULTS: In multivariate corrected linear regression analysis, infants of women with subclinical hypothyroidism demonstrated a significantly lower receptive communication score (ß = -0.63, 95% CI [-1.12, -0.14], P = 0.013), with stratified analysis showing a significant association among female offspring (ß = -0.87, 95% CI [-1.59, -0.15], P = 0.018) but null association among male offspring (ß = -0.44, 95% CI [-1.03, 0.15], P = 0.145). No significant differences were found in assisted pregnancy population with normal thyroid function and positive antibodies according to the diagnostic cut-offs applied to normal pregnant women. CONCLUSIONS: Subclinical hypothyroidism in assisted pregnancies correlates with lower communication scores in 1-year-olds, especially in girls. Recommending medication for subclinical hypothyroidism throughout, regardless of thyroid autoantibody status.

Association of Breastfeeding and Neonatal Jaundice With Infant Neurodevelopment.

INTRODUCTION: Exclusive breastfeeding is advantageous for infant neurodevelopment. Nevertheless, insufficient human milk supply in exclusively breastfed infants may elevate the risk of neonatal jaundice, which can potentially result in neurological harm. Whether mothers should adhere to exclusive breastfeeding in infants with neonatal jaundice remains unclear. METHODS: Data comes from the Jiangsu Birth Cohort (JBC), a prospective and longitudinal birth cohort study in China. A total of 2,577 infants born from November 2017 to March 2021 were included in the analysis. Multivariate linear regression models were used to analyze the associations between breastfeeding status, neonatal jaundice, and their interaction with infant neurodevelopment. Analysis was performed in 2022. RESULTS: Compared with "exclusive breastfeeding," fine motor scores of infants were lower for "mixed feeding" (ßadj, -0.16; 95% CI, -0.29 to -0.03; p=0.016) and "no breastfeeding" (ßadj, -0.41; 95% CI, -0.79 to -0.03; p=0.034). Compared with "no neonatal jaundice," infants with "severe neonatal jaundice" had lower scores for cognition (ßadj, -0.44; 95% CI, -0.66 to -0.23; p<0.001) and fine motor (ßadj, -0.19; 95% CI, -0.35 to -0.03; p=0.024). In infants with severe neonatal jaundice, the termination of exclusive breastfeeding before 6 months was associated with worse cognition (ßadj, -0.28; 95% CI, -0.57 to 0.01), while this association was not observed in those without neonatal jaundice (ßadj, 0.09; 95% CI, -0.26 to 0.43). CONCLUSIONS: Exclusive breastfeeding for the first 6 months is beneficial to the neurodevelopment of infants, especially in those with severe neonatal jaundice.

Association of maternal hypertensive disorders in pregnancy with infant neurodevelopment.

Inconsistent findings have been reported regarding the associations between hypertensive disorders in pregnancy (HDP) and infant neurodevelopment. Leveraging data from the Jiangsu Birth Cohort, in the present study, we re-visited such associations in one-year-old infants from 2576 singleton pregnancies and 261 twin pregnancies. We first assessed infant neurodevelopment by the Bayley Scales of Infant and Toddler Development Screening Test (the Third Edition), and then estimated its association with maternal HDP using general linear regression models and Poisson regression models. In singleton pregnancies, compared with mothers unexposed to HDP, infants born to mothers with chronic hypertension exhibited a lower score ( ß, -0.67; 95% confidence interval [CI], -1.19--0.15) and a higher risk of "non-optimal" gross motor development (risk ratio [RR], 2.21; 95% CI, 1.02-4.79); in twin pregnancies, infants born to mothers with HDP exhibited lower scores in cognition ( ß, -0.49; 95% CI, -0.96--0.01), receptive communication ( ß, -0.55; 95% CI, -1.03--0.06), and gross motor ( ß, -0.44; 95% CI, -0.86--0.03), and at a higher risk of "non-optimal" gross motor development (RR, 2.12; 95% CI, 1.16-3.88). These findings indicate that infants born to mothers with HDP may have inferior neurodevelopment outcomes at the age of one year.

Association between prenatal exposure to trace elements mixture and visual acuity in infants: A prospective birth cohort study.

BACKGROUND: Prenatal environmental factors may affect the development of the offspring and can bring long lasting consequences to the offspring's health. To date, only few studies have reported inconclusive association between prenatal single trace element exposure and visual acuity, and no studies have investigated the association between prenatal exposure to trace elements mixture and visual acuity in infants. METHODS: In the prospective cohort study, grating acuity in infants (12 ± 1 months) was measured by Teller Acuity Cards II. Concentrations of 20 trace elements in maternal urine samples collected in early-trimester were measured by Inductively Coupled Plasma Mass Spectrometry. Elastic net regression (ENET) was applied to select important trace elements. Nonlinear associations of the trace elements levels with abnormal grating were explored using the restricted cubic spline (RCS) method. The associations between selected individual elements and abnormal grating acuity were further appraised using the logistic regression model. Then Bayesian Kernel Machine Regression (BKMR) was used to estimate the joint effects of mixture and interactions between trace elements combining with NLinteraction. RESULTS: Of 932 mother-infant pairs, 70 infants had abnormal grating acuity. The ENET model produced 8 trace elements with non-zero coefficients, including cadmium, manganese, molybdenum, nickel, rubidium, antimony, tin and titanium. RCS analyses identified no nonlinear associations of the 8 elements with abnormal grating acuity. The single-exposure analyses using logistic regression revealed that prenatal molybdenum exposure possessed a significantly positive association with abnormal grating acuity (odds ratio [OR]: 1.44 per IQR increase, 95% confidence interval [CI]: 1.05, 1.96; P = 0.023), while prenatal nickel exposure presented with a significantly inverse association with abnormal grating acuity (OR: 0.64 per IQR increase, 95% CI: 0.45, 0.89; P = 0.009). Similar effects were also observed in BKMR models. Moreover, the BKMR models and NLinteraction method identified potential interaction between molybdenum and nickel. CONCLUSIONS: We established that prenatal exposure to high concentration of molybdenum and low concentration of nickel was associated with the increased risk of abnormal visual acuity. Potential interaction may exist between molybdenum and nickel on abnormal visual acuity.

Association between PM2.5 exposure and the outcomes of ART treatment: A prospective birth cohort study.

Exposure to fine particulate matter (PM2.5) has been reported to be adversely associated with reproductive health. However, current evidence on PM2.5 exposure adversely influencing pregnancy outcomes remains inconclusive. Women receiving assisted reproductive technology (ART) treatment are under close monitoring with regards to their treatment process, which make them great study population to assess the impact of PM2.5 in the post-implantation period. Therefore, within a prospective cohort study in Jiangsu, China, we assessed the associations between exposure to ambient PM2.5 and the outcomes of ART treatment, including implantation failure, biochemical pregnancy loss, clinical pregnancy and live birth, in 2431 women who underwent the first fresh embryo transfer or frozen embryo transfer cycle. High-performance machine-learning model was performed to estimate daily PM2.5 exposure concentrations at 1 km spatial revolution. Exposure windows were divided into seven periods according to the process of follicular and embryonic development in ART. Generalized estimation equations (GEE) was used to assess the association between PM2.5 and ART outcomes. Higher PM2.5 exposure was associated with decreased probability of clinical pregnancy (RR: 0.98, 95 % CI: 0.96-1.00). Each 10 µg/m3 increase in PM2.5 exposure in the duration from hCG test to 30 days after embryo transfer (Period 7) was positively associated with the risk of biochemical pregnancy loss (RR: 1.06, 95 % CI: 1.00-1.13), and more prominent effects were observed in women undergoing fresh embryo transfer. Null associations were observed between PM2.5 exposure and implantation failure or live birth at any exposure window. Collectively, our study suggested that exposure to PM2.5 increased the risk of adverse treatment outcomes in the ART population. Thus, for women opting for ART treatment, particularly those who select fresh embryo transfer cycles, additional evaluation of PM2.5 exposure before treatment might be of value in decreasing the risk of adverse pregnancy outcomes.

Prenatal titanium exposure and child neurodevelopment at 1 year of age: A longitudinal prospective birth cohort study.

Previous animal studies provided the evidence that prenatal titanium exposure can cause neurotoxicity in their offspring, while human data is vacant. Our aim was to identify the associations of prenatal titanium exposure with the child neurodevelopment. Participants in present study were recruited during early pregnancy between 2014 and 2017. Urinary concentrations of titanium at first trimester were determined. We assessed child neurodevelopment using the Chinese version of Gesell Developmental Schedules at first year follow-up. The multivariable linear regressions and the robust modified Poisson regressions were used to estimate the associations of specific gravity corrected urinary titanium concentrations with the child neurodevelopment. In adjusted models, children's developmental quotient scores in the language domain were 2.03 points (95% CI: -3.66, -0.40) lower in the highest tertile of prenatal urinary titanium than in the lowest tertile. Also, children with prenatal urinary titanium in the highest tertile had 1.42 times (95% CI: 1.17, 1.72) increased risk of language development delay compared to those in the lowest tertile. No statistically significant associations were observed between titanium exposure and child development delay in motor, adaptive and social areas. The findings indicated that prenatal higher titanium exposure was associated with impaired language development, suggesting that titanium might act as developmental neurotoxicants.

Leukocyte telomere length in children born following blastocyst-stage embryo transfer.

Perinatal and childhood adverse outcomes associated with assisted reproductive technology (ART) has been reported, but it remains unknown whether the initial leukocyte telomere length (LTL), which is an indicator of age-related phenotypes in later life, is affected. Here, we estimated the LTLs of 1,137 individuals from 365 families, including 202 children conceived by ART and 205 children conceived spontaneously from two centers of the China National Birth Cohort, using whole-genome sequencing (WGS) data. One-year-old children conceived by ART had shorter LTLs than those conceived spontaneously (beta, -0.36; P = 1.29 × 10-3) after adjusting for plurality, sex and other potential confounding factors. In particular, blastocyst-stage embryo transfer was associated with shorter LTL (beta, -0.54, P = 2.69 × 10-3) in children conceived by ART. The association was validated in 586 children conceived by ART from five centers using different LTL quantification methods (that is, WGS or qPCR). Blastocyst-stage embryo transfer resulted in shorter telomere lengths in mice at postnatal day 1 (P = 2.10 × 10-4) and mice at 6 months (P = 0.042). In vitro culturing of mice embryos did not result in shorter telomere lengths in the late cleavage stage, but it did suppress telomerase activity in the early blastocyst stage. Our findings demonstrate the need to evaluate the long-term consequences of ART, particularly for aging-related phenotypes, in children conceived by ART.

Associations of maternal dietary patterns during pregnancy and fetal intrauterine development.

Dietary pattern is excellent in reflecting an individual's eating conditions. Longitudinal data on fetal growth can reflect the process of intrauterine growth. We aimed to evaluate the associations between maternal dietary patterns and intrauterine parameters in middle and late pregnancy. The present study was conducted within Jiangsu Birth Cohort (JBC) study. Dietary information was assessed with a food frequency questionnaire (FFQ) in the second and third trimester of gestation. B-ultrasound scans were performed to obtain fetal intrauterine parameters, including head circumference (HC), femur length (FL), abdominal circumference (AC), and estimated fetal weight (EFW). Exploratory factor analysis was used to extract dietary patterns. Multiple linear regression and linear mixed-effects model (LMM) were used to investigate the association between maternal dietary patterns and fetal growth. A total of 1,936 pregnant women were eligible for the study. We observed inverse associations of maternal "Vegetables and fish" and "Snack and less eggs" patterns during mid-pregnancy with fetal HC Z-score, respectively ("Vegetables and fish": ß = -0.09, 95% CI -0.12, -0.06; "Snack and less eggs": ß = -0.05, 95% CI -0.08, -0.02). On the contrary, "Animal internal organs, thallophyte and shellfish" pattern in the second trimester was associated with increased HC Z-scores (ß = 0.04, 95% CI 0.02, 0.06). Consistently, score increase in "Vegetables and fish" pattern in the third trimester was inversely associated with the Z-scores of HC (ß = -0.05, 95% CI -0.09, -0.02), while "Meat and less nuts" pattern was positively correlated with the Z-scores of HC (ß = 0.04, 95% CI 0.02, 0.07). As compared to the fetus whose mothers at the lowest tertile of "Snack and less eggs" pattern in both trimesters, those whose mothers at the highest tertile demonstrated 1.08 fold (RR = 2.10, 95% CI 1.34-3.28) increased risk of small HC for gestational age (GA). No correlation was observed between maternal dietary patterns and other intrauterine parameters. Our results suggested the effects of maternal dietary patterns on fetal growth, particularly HC. These findings highlighted the adverse impact of unhealthy dietary pattern on fetal growth, might provide evidence for strategies to prevent intrauterine dysplasia and dietary guidelines during pregnancy.

Maternal exposure to metal mixtures during early pregnancy and fetal growth in the Jiangsu Birth Cohort, China.

Previous epidemiological studies have reported that prenatal exposure to metals might have influence on fetal growth. Most studies assessed the effect of individual metals, while the investigation on the relationship between multiple metal exposure and fetal growth is sparse. The objective of the present study is to assess the joint impact of metal mixtures on fetal growth during pregnancy. A total of 1275 maternal-infant pairs from the Jiangsu Birth Cohort (JBC) Study were included to investigate the effect of maternal metal exposure on fetal biometry measures at 22-24, 30-32, and 34-36 weeks of gestation. Lead (Pb), arsenic (As), cadmium (Cd), mercury (Hg), chromium (Cr), vanadium(V), thallium (Tl) and barium (Ba) were measured by inductively coupled plasma mass spectrometry (ICP-MS) in maternal urine samples collected in the first trimester. We used general linear models and restricted cubic splines to test dose-response relationships between single metals and fetal growth. The weighted quantile sum (WQS) models were then applied to evaluate the overall effect of all these metals. We observed inverse associations of exposure to Pb, V and Cr with estimated fetal weight (EFW) at 34-36 weeks of gestation. Notably, maternal exposure to metal mixtures was significantly associated with reduced EFW at 34-36 weeks of gestation after adjusting for some covariates and confounders (aß -0.05 [95% CI: 0.09, -0.01], P = 0.023), and this association was mainly driven by Cr (30.41%), Pb (23.92%), and Tl (15.60%). These findings indicated that prenatal exposure to metal mixtures might impose adverse effects on fetal growth.

Association of Maternal Mild Hypothyroidism With Offspring Neurodevelopment in TPOAb-Negative Women: A Prospective Cohort Study.

Objectives: Adequate maternal thyroid hormone availability is crucial for fetal neurodevelopment, but the role of maternal mild hypothyroidism is not clear. We aim to investigate the association of maternal mild hypothyroidism with neurodevelopment in infants at 1 year of age among TPOAb-negative women. Methods: The present study was conducted within the Jiangsu Birth Cohort. A total of 793 mother-infant pairs were eligible for the present study. Maternal thyroid function was assessed by measuring serum thyroid-stimulating hormone, free thyroxine, and thyroid peroxidase antibodies. Neurodevelopment of infants was assessed by using the Bayley Scales of Infant and Toddler Development third edition screening test (Bayley-III screening test). Results: In the multivariate adjusted linear regression analyses, infants of women with subclinical hypothyroidism and isolated hypothyroxinemia were associated with decreased receptive communication scores (ß = -0.68, p = 0.034) and decreased gross motor scores (ß = -0.83, p = 0.008), respectively. Moreover, infants of women with high-normal TSH concentrations (3.0-4.0 mIU/L) and low FT4 concentrations were significantly associated with lower gross motor scores (ß = -1.19, p = 0.032), while no differences were observed in infants when the mothers had a high-normal TSH concentration and normal FT4 levels. Conclusions: Maternal subclinical hypothyroidism is associated with decreased receptive communication scores in infants at 1 year of age. In addition, maternal TSH concentration greater than 4.0 mIU/L and maternal isolated hypothyroxinemia are associated with impaired gross motor ability of infants, especially in infants of women with high-normal TSH concentrations (3.0-4.0 mIU/L).

The continuing evolution of birth cohort studies: achievements and challenges†.

Well-designed birth cohorts are able to estimate prevalence/distribution of various health events/outcomes, and to link early-life origins with adult health and function. The past two decades have seen a surge in the establishment of new birth cohorts and their accompanying research. We discussed distinct designs of current birth cohort studies, reviewed their achievements, and highlighted insights obtained from birth cohort studies, as well as challenges we are facing. Birth cohort studies are providing increasing opportunities to identify determining factors for short- and long-term health, yielding substantial evidence to uncover biological mechanisms of diseases and phenotypes, and providing further insights for public health. Dynamic monitoring, accurate measurements, long-term follow-ups, and collaborative efforts are warranted in new birth cohorts to elucidate the nature of life course relationships in contemporary generation.

Associations between antenatal corticosteroid exposure and neurodevelopment in infants.

BACKGROUND: It has been well recognized that antenatal administration of dexamethasone to pregnant women at risk of preterm delivery may markedly accelerate fetal maturation and reduce the risk of adverse perinatal outcomes in their preterm infants, particularly for births before 34 weeks of gestation. Since 2015, antenatal corticosteroid administration has been extended beyond 34 weeks of gestation by clinical guidelines, as it might have beneficial effects on fetal maturation and perinatal outcomes. However, concerns regarding the potential influence of antenatal corticosteroid treatment on offspring neurodevelopment have been raised. OBJECTIVE: This study aimed to investigate whether maternal antenatal corticosteroid administration was associated with neurodevelopment in infants at 1 year of age. STUDY DESIGN: In this prospective and longitudinal birth cohort study, women were followed up throughout gestation, and their infants underwent a Bayley Scales of Infant and Toddler Development, Third Edition, screening test at 1 year of age between December 2018 and September 2020. Finally, 1609 pregnant women and 1759 infants were included in the current study. Using a generalized linear mixed model, we examined the association between antenatal corticosteroid exposure and infant neurodevelopment in cognitive, receptive communication, expressive communication, fine motor, and gross motor functions. RESULTS: Of the 1759 infants eligible for this study, 1453 (82.6%) were singletons. A total of 710 infants were exposed to antenatal corticosteroids, among whom 415 were dexamethasone exposed and 483 were prednisone exposed. Dexamethasone was prescribed most often in late pregnancy, whereas prednisone was often used before 8 weeks of gestation among women who conceived through assisted reproductive technology. Compared with those who had no exposure, antenatal corticosteroid exposure was associated with an increased risk of infants being noncompetent in the cognitive development domain after adjusting for conventional risk factors (adjusted risk ratio, 1.53; 95% confidence interval, 1.08-2.18; P=.017). For medication-specific exposure, those exposed vs not exposed to antenatal dexamethasone were 1.62-fold (95% confidence interval, 1.10-2.38; P=.014) more likely to be noncompetent in the cognitive development domain at 1 year. The association did not vary markedly between preterm and term infants, singletons and twins, or assisted reproductive technology-conceived and spontaneously conceived infants (all P>.05 for heterogeneity). In contrast, a null association was observed for the risk of being noncompetent in any domain of neurodevelopment with antenatal prednisone exposure at early pregnancy. CONCLUSION: Here, antenatal corticosteroid, particularly dexamethasone exposure, was markedly associated with an increased risk of infants being noncompetent in the cognitive development domain at 1 year of age. These findings may provide new information when weighing the benefits and potential risks of maternal antenatal corticosteroid administration.

Maternal PM2.5 exposure during gestation and offspring neurodevelopment: Findings from a prospective birth cohort study.

Emerging data have suggested the potential role of prenatal PM2.5 exposure as a neurotoxin for offspring. However, the existing results are equivocal, and no study has examined the effects of complex chemical constituents of the particular matter on offspring neurodevelopment. Therefore, in a prospective birth cohort study conducted in Jiangsu, China, we aimed to investigate the association between prenatal exposure to PM2.5 and the neurodevelopment in infants, and further assess the effects of specific chemical constituents of PM2.5. A total of 1531 children who had available data on daily prenatal PM2.5 exposure and completed assessment on neurodevelopment at 1 year old were enrolled. We used the high-performance machine-learning model to estimate daily PM2.5 exposure concentrations at 1 km × 1 km spatial resolution. The combined geospatial-statistical model was applied to evaluate average concentrations of six chemical constituents [organic matter (OM), black carbon (BC), sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and soil dust (Dust)]. The neurodevelopment of children was assessed using Bayley-III Screening Test. After adjusting for confounding factors, the risk of non-optimal gross motor development increased by 31 % for every 10 µg/m3 increase in average PM2.5 exposure during gestation (aRR: 1.31; 95 % CI: 1.04, 1.64). Further analysis of PM2.5 constituents showed that prenatally exposed to high SO42- was associated with the risk of non-optimal gross motor development (aRR: 1.40; 95 % CI: 1.08, 1.81). Null associations were observed for the rest four neurodevelopment domains. Collectively, our study suggested that prenatal exposure to PM2.5, particularly with high SO42- concentration, was associated with children's non-optimal gross motor development at 1 year old. The short- and long-term influences of perinatal PM2.5 exposure on children's neurodevelopment warrant further investigation.

Association of Maternal Dietary Patterns during Gestation and Offspring Neurodevelopment.

The health effects of diet are long term and persistent. Few cohort studies have investigated the influence of maternal dietary patterns during different gestational periods on offspring's health outcomes. This study investigated the associations between maternal dietary patterns in the mid- and late-gestation and infant's neurodevelopment at 1 year of age in the Jiangsu Birth Cohort (JBC) Study. A total of 1178 mother-child pairs were available for analysis. A semiquantitative food frequency questionnaire (FFQ) was used to investigate dietary intake at 22-26 and 30-34 gestational weeks (GWs). Neurodevelopment of children aged 1 year old was assessed using Bayley-Ⅲ Screening Test. Principal component analysis (PCA) and Poisson regression were used to extract dietary patterns and to investigate the association between dietary patterns and infant neurodevelopment. After adjusting for potential confounders, the maternal 'Aquatic products, Fresh vegetables and Homonemeae' pattern in the second trimester was associated with a lower risk of being non-competent in cognitive and gross motor development, respectively (cognition: aRR = 0.84; 95% CI 0.74-0.94; gross motor: aRR = 0.80; 95% CI 0.71-0.91), and the similar pattern, 'Aquatic products and Homonemeae', in the third trimester also showed significant association with decreased risk of failing age-appreciate cognitive and receptive communication development (cognition: aRR = 0.89; 95% CI 0.80-0.98; receptive communication: aRR = 0.91; 95% CI 0.84-0.99). Notably, adherence to the dietary pattern with relatively high aquatic and homonemeae products in both trimesters demonstrated remarkable protective effects on child neurodevelopment with the risk of being non-competent in cognitive and gross motor development decreasing by 59% (95% CI 0.21-0.79) and 63% (95% CI 0.18-0.77), respectively. Our findings suggested that adherence to the 'Aquatic products and Homonemeae' dietary pattern during pregnancy may have optimal effects on offspring's neurodevelopment.

Stress, anxiety, and depression in infertile couples are not associated with a first IVF or ICSI treatment outcome.

BACKGROUND: Psychological distress may exert a negative influence on reproductive function of couples at reproductive age. Couples seeking assisted reproductive technology (ART) treatment may have a higher prevalence of psychological distress than fertile couples. However, whether psychological distress is associated with the outcome of ART treatment remains unknown. We aimed to investigate the association of pre-treatment psychological distress and clinical pregnancy rate among infertility couples undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) treatment. METHODS: This nested case-control study was conducted based on women who underwent their first fresh IVF or ICSI cycle in the Jiangsu Birth Cohort Study (JBC) between November 2015 and January 2019. A total of 150 women who did not obtain clinical pregnancy after first IVF or ICSI fresh embryo transfer were identified as cases, and a total of 300 age matched women who obtained clinical pregnancy were identified as controls. Conditional logistic regression analyses were used to investigate the association between psychological distress and the outcome of first IVF or ICSI treatment, adjusting for multiple potential confounders. RESULTS: No statistically significant association was observed between score of maternal symptoms of psychological distress and clinical pregnancy. Adjusted ORs of logistic regression were 1.00 (95% CI 0.97-1.03) for anxiety, 0.98 (95% CI 0.95-1.02) for depression, and 0.98 (95% CI 0.95-1.01) for perceived stress, respectively. When treat depression and anxiety as categorical variables, 62 (13.8%) were classified as clinical depression, 11 (2.4%) were classified as clinical anxiety, among 450 women in the present study. Psychological distress symptoms were also not associated with clinical pregnancy rate. Adjusted ORs of logistic regression were 0.27 (95% CI 0.03-2.33) for anxiety, 0.88 (95% CI 0.46-1.68) for depression, respectively. CONCLUSIONS: Our findings firstly indicated that psychological distress experienced prior to IVF/ICSI treatment was not associated with clinical pregnancy.