Placental inflammatory cytokines mRNA expression and preschool children's cognitive performance: a birth cohort study in China.

BACKGROUND: The immunologic milieu at the maternal-fetal interface has profound effects on propelling the development of the fetal brain. However, accessible epidemiological studies concerning the association between placental inflammatory cytokines and the intellectual development of offspring in humans are limited. Therefore, we explored the possible link between mRNA expression of inflammatory cytokines in placenta and preschoolers' cognitive performance. METHODS: Study subjects were obtained from the Ma'anshan birth cohort (MABC). Placental samples were collected after delivery, and real-time quantitative polymerase chain reaction (RT-qPCR) was utilized to measure the mRNA expression levels of IL-8, IL-1ß, IL-6, TNF-α, CRP, IFN-γ, IL-10, and IL-4. Children's intellectual development was assessed at preschool age by using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). Multiple linear regression and restricted cubic spline models were used for statistical analysis. RESULTS: A total of 1665 pairs of mother and child were included in the analysis. After adjusting for confounders and after correction for multiple comparisons, we observed that mRNA expression of IL-8 (ß = - 0.53; 95% CI, - 0.92 to - 0.15), IL-6 (ß = - 0.58; 95% CI, - 0.97 to - 0.19), TNF-α (ß = - 0.37; 95% CI, - 0.71 to - 0.02), and IFN-γ (ß = - 0.31; 95% CI, - 0.61 to - 0.03) in the placenta was negatively associated with preschoolers' full scale intelligence quotient (FSIQ). Both higher IL-8 and IL-6 were associated with lower children's low fluid reasoning index (FRI), and higher IFN-γ was associated with lower children's working memory index (WMI). After further adjusting for confounders and children's age at cognitive testing, the integrated index of six pro-inflammatory cytokines (index 2) was found to be significantly and negatively correlated with both the FSIQ and each sub-dimension (verbal comprehension index (VCI), visual spatial index (VSI), FRI, WMI, processing speed index (PSI)). Sex-stratified analyses showed that the association of IL-8, IFN-γ, and index 2 with children's cognitive development was mainly concentrated in boys. CONCLUSIONS: Evidence of an association between low cognitive performance and high expression of placental inflammatory cytokines (IL-8, IL-6, TNF-α, and IFN-γ) was found, highlighting the potential importance of intrauterine placental immune status in dissecting offspring cognitive development.

Early sleep duration trajectories and children's cognitive development: a prospective cohort study.

We aimed to investigate the association between sleep duration trajectories and cognitive performance in preschool-aged Chinese children. We included 2131 children from the Ma'anshan birth cohort (MABC) study. Sleep duration trajectories from 6 to 48 months of age were determined using the group-based trajectory modeling (GBTM). Children's intellectual development was assessed using the Wechsler Preschool and Primary Scale of Intelligence. Compared to those with a medium total sleep duration trajectory, children with a short total sleep duration trajectory had poorer cognitive performance on the Visual Spatial Index (VSI) (ß = -3.65; 95% CI = -6.77 to -0.53), which was associated with an increased risk of a low full-scale intelligence quotient (FSIQ) (OR = 1.60; 95% CI = 1.02 to 2.51). The short total sleep duration trajectory was associated with a low VSI compared with both the medium total sleep duration trajectory and the long total sleep duration trajectory. Compared to children with normal nighttime sleep duration and normal daytime sleep duration trajectories, children with short nighttime sleep and long daytime sleep duration trajectories, normal nighttime sleep and long daytime sleep duration trajectories, and short nighttime sleep and normal daytime sleep duration trajectories all had lower cognitive performance. The restricted cubic spline (RCS) also showed that children with and appropriate total sleep duration, an adequate nighttime sleep duration, and a moderate daytime sleep duration had higher FSIQ. CONCLUSIONS: The results of this study emphasize that a medium total sleep duration, adequate sleep at nighttime, and appropriate sleep in the daytime appear to be more beneficial for children's cognitive development. WHAT IS KNOWN: • Sleep duration in infancy is strongly associated with neurocognitive development. WHAT IS NEW: • Medium and long total sleep duration trajectories are beneficial for children's cognitive performance compared to the short total sleep duration trajectory. • A medium total sleep duration, adequate sleep at nighttime and appropriate sleep in the daytime appear to be more beneficial for children's cognitive development.

Maternal pregnancy-related anxiety and children's physical growth: the Ma'anshan birth cohort study.

BACKGROUND: Epidemiological studies have identified maternal antenatal anxiety and several adverse birth outcomes, but limited studies have focused on the relationship with the long-term physical growth of children. The study aimed to assess the influence of maternal pregnancy-related anxiety on physical growth in children at different exposure periods during pregnancy. METHODS: 3,154 mother-child pairs were included based on the Ma'anshan birth cohort study. Maternal prenatal anxiety was obtained by administering a questionnaire using the pregnancy-related anxiety questionnaire (PRAQ) scale during the 1st, 2nd and 3rd trimesters of pregnancy. Body fat (BF) (48 to 72 months) and Body Mass Index (BMI) (birth to 72 months) were collected repeatedly for children. Group-based trajectory models were applied to fit the different trajectories of BMI and BF. RESULTS: Maternal anxiety in the 2nd (OR = 0.81; 95% CI: 0.68 to 0.98; P < 0.025) and 3rd (OR = 0.80; 95% CI: 0.67 to 0.97; P = 0.020) trimesters was associated with a decreased risk of rapid weight gain (RWG) in the first year of life. Children aged 48 to 72 months of mothers with anxiety in the 3rd trimester had lower BMI (ß = -0.161; 95% CI, -0.293 to -0.029; P = 0.017) and BF (ß = -0.190; 95% CI, -0.334 to -0.046; P = 0.010), and these children were less likely to develop a very high BMI trajectory (OR = 0.54; 95% CI: 0.34 to 0.84; P = 0.006), and a high BF trajectory (OR = 0.72; 95% CI: 0.53 to 0.99; P = 0.043). Similar associations were found between maternal anxiety in both 2nd and 3rd trimesters and children's physical growth. CONCLUSIONS: Offspring of mothers with prenatal anxiety in the 2nd and 3rd trimesters predicts poorer growth in infancy and preschool age. Early improvement and treatment of prenatal anxiety could benefit physical health and development in early childhood.

Birth outcomes and early growth patterns associated with age at adiposity rebound: the Ma'anshan birth cohort (MABC) study.

OBJECTIVE: Early onset of adiposity rebound (AR) is considered an early indicator of obesity risk. Our objective was to investigate the association of birth outcomes and early physical growth patterns with early AR in children. METHODS: Study subjects (n = 2705) were enrolled from the Ma'anshan birth cohort (MABC). The body mass index (BMI), head circumference, waist circumference, and body fat were collected. Rapid weight gain (RWG) was defined by the change in weight standard-deviation score in the first two years of life. Group-based trajectory modeling (GBTM) was used to determine children's physical growth trajectories. The age of AR was fitted using fractional polynomial function models. RESULTS: Children with very high BMI trajectories (RR = 2.83; 95% CI 2.33 to 1.40), rising BMI trajectories (RR = 3.15; 95% CI 2.66 to 3.72), high waist circumference trajectories (RR = 4.17; 95% CI 3.43 to 5.06), and high body fat trajectories (RR = 3.01; 95% CI 2.62 to 3.46) before 72 months of age were at a greater risk of experiencing early AR. Low birth weight (LBW) (RR = 1.86; 95% CI 1.28 to 2.51), preterm birth (PTB) (RR = 1.50; 95% CI 1.17 to 1.93), and small for gestational age (SGA) (RR = 1.37; 95% CI 1.14 to 1.64) associated with increased risk of early AR. Moreover, infants experiencing RWG (RR = 1.59; 95% CI 1.40 to 1.83), low BMI trajectories (RR = 1.27; 95% CI 1.06 to 1.53) and rising BMI trajectories (RR = 1.50; 95% CI 1.22 to 1.84) in the first two years were at higher risk of developing early AR subsequently. Compared to the group with non-early AR, the BMI of children with early AR tended to be lower first (from birth to 6 months of age) and then higher (from 18 to 72 months of age). CONCLUSIONS: Children with overall high BMI, high waist circumference, and high body fat before 72 months of age are more likely to experience early AR, but infants with low BMI trajectories, rising BMI trajectories and infants experiencing RWG in the first two years of life similarly increase the risk of early AR. These results can help to understand the early factors and processes that lead to metabolic risks.

Age at adiposity rebound and the relevance for obesity: a systematic review and meta-analysis.

OBJECTIVES: To understand the sex difference in age at adiposity rebound (AR), integrate the prevalence of early AR (EAR), and provide a quantitative association between early age at AR and overweight/obesity. METHODS: Literature review was conducted in different databases, including the Web of Science, PubMed, EMBASE, Wiley, Chinese National Knowledge Infrastructure, and ScienceDirect databases up to August 2021. Studies that reported data related to AR were considered for inclusion. Pooled effect sizes and their respective 95% confidence intervals (CIs) were calculated using random effects models, depending on the size of heterogeneity. Heterogeneity was tested by using the I2 statistics. RESULTS: 28 studies with a combined sample size of 106,397 people were included in the final meta-analysis. Girls had a significantly earlier age of AR than boys (mean difference = 3.38 months; 95% CI 2.14-4.63). The overall prevalence of EAR was 40% (95% CI 31% to 50%), and the prevalence in girls was 5% higher than that in boys based on the definition of age at AR < 5.0-5.1 years. The overall pooled prevalence of EAR showed an increasing trend by child's birth year [1934-1973]: 29% (95% CI 22% to 37%), 1991-2001: 35% (95% CI 26% to 44%), and 2002-2009: 52% (95% CI 40-63%). Early age at AR (age at AR < 5.0-5.1 years) was associated with a significantly increased risk of overweight/obesity (OR = 5.07; 95% CI 3.60-7.12), overweight (OR = 3.10; 95% CI 1.69-5.70), and obesity (OR = 6.97; 95% CI 4.32-11.26) from the preschool period to adulthood. CONCLUSIONS: The overall prevalence of EAR is increasing, and girls experience AR earlier than boys. The early age at AR in children may be an early and effective marker of obesity.

Sex-specific association between placental inflammatory cytokine mRNA expression and preschoolers' behavioral development: The Ma'anshan birth cohort study.

BACKGROUND: Placental inflammation may contribute to brain abnormalities and childhood neuropsychiatric disorders, but limited knowledge is available on the association of placental inflammatory cytokine levels and offspring's behavioral development. This study aimed to examine the sex-specific association between placental inflammatory cytokine mRNA expression and preschoolers' behavioral development. METHODS: 3474 pregnant women were recruited as the initial study population in the Ma'anshan birth cohort (MABC) study. Placentas (n = 2519) were collected during childbirth, and the mRNA expression of IL-8, IL-1ß, CRP, TNF-α, IL-6, IL-10, and IL-4 was assessed. The Child Behavior Checklist 1.5-5 (CBCL 1.5-5) was used to assess children's behavioral development at 4 years old. A T-score ≥ 60 on summary scales or a score ≥ 65 on syndrome scales was regarded as the borderline clinical range. Multiple linear regression models and binary logistic regression models were applied to explore the sex-specific associations between placental inflammatory cytokines mRNA transcript levels and preschoolers' behavioral development. RESULTS: Sex-specific associations between placental inflammatory cytokines mRNA expression and preschoolers' behavioral development were observed. There was a positive association between IL-8 and CBCL scores for boys on anxious/depressed problems, aggressive behaviors, externalizing problems and total problems. Logistic regression models showed that high levels of IL-8 were associated with a higher risk of girls' emotionally reactive problems and sleep problems compared to low/medium levels. High TNF-α was correlated with increased sleep problem scores in boys, and medium TNF-α (vs. low levels) was associated with an increased risk of girls' externalizing problems. Medium levels of CRP, IL-1ß, and IL-6 were found to be associated with a decreased risk of girls' behavioral problems compared to low/high levels. For anti-inflammatory cytokines, medium IL-10 and IL-4 (vs. low levels) were observed to be associated with a lower risk of internalizing problems in boys and externalizing problems in girls, respectively. High IL-10 was correlated with decreased attention problem scores in boys. CONCLUSION: This study indicates that placental inflammatory cytokine mRNA expression of IL-8, CRP, TNF-α, IL-1ß, IL-4 and IL-10 may be associated with preschoolers' behavioral development in a sex-specific manner.

Association between maternal fasting glucose levels throughout pregnancy and preschoolers' refractive errors.

PURPOSE: We aimed to investigate the association between maternal fasting plasma glucose (FPG) trajectories during pregnancy and children's refractive errors at 6 years old. DESIGN: Based on the Ma'anshan Birth Cohort (MABC) in China, a total of 1987 mother-child pairs were included in this study. METHODS: Using the group-based trajectory model, trajectory fitting was performed on fasting blood glucose levels during the first, second, and third trimesters of pregnancy. Children's vision was measured at 6 years of age using the standard logarithmic visual acuity E-chart and cycloplegic refraction examination. Logistic regression models and multi-informant generalized estimating equations were used to analyze the association between maternal blood glucose level and 6-year-old children's visual acuity. RESULTS: Children born of mothers with high level FPG trajectory had a higher risk of developing refractive error [OR=1.46 (95% CI 1.08 1.97)], hypermetropia [OR=1.64 (95% CI 1.09, 2.46)] and astigmatism [OR=1.60 (95% CI 1.06, 2.41)] at age six compared to those with low level trajectory. Maternal blood glucose level in the first [ß=-0.012 (95% CI -0.024, -0.001)] and the second [ß=-0.016 (95% CI -0.025, -0.006)] trimesters was associated with 6 year children's distance vision value. CONCLUSIONS: High level of fasting plasma glucose trajectories during pregnancy has been observed to be associated with 6-year-old children's refractive error, hypermetropia and astigmatism. The first and the second trimesters may be critical periods for the effects of maternal blood glucose on children's vision. The long-term effect of maternal glucose metabolism on children's visual development deserves further study.

The impact of maternal anxiety during pregnancy on children's eczema and allergic rhinitis: The Ma'anshan birth cohort study.

OBJECTIVE: The objective of this study was to investigate the associations between maternal exposure to anxiety during pregnancy and the susceptibility of offspring to eczema and allergic rhinitis and the possibility of sensitivity periods and cumulative effects. METHODS: The study's sample consisted of 3160 mother-child pairs from the Ma'anshan Birth Cohort Study. Maternal anxiety was repeatedly measured in the 1st, 2nd, and 3rd trimesters of pregnancy using the Chinese version of the Pregnancy-Related Anxiety Scale. Information regarding children's eczema and allergic rhinitis diagnoses was collected through parental reports at 12, 24, 36 and 48 months of age. Binary logistic regression models were used for statistical analysis and corrected for multiple comparisons using the false discovery rate (FDR) method. RESULTS: Children whose mothers experienced anxiety throughout pregnancy had the highest odds of developing total eczema (aOR 1.45, 95% CI 1.02-2.07) and total allergic rhinitis (aOR 1.67, 95% CI 1.17-2.37) between the ages of 6 and 48 months. The higher the trajectory of the maternal anxiety scores throughout pregnancy, the higher the odds of total eczema (aOR 1.65, 95% CI 1.14-2.40) and allergic rhinitis (aOR 1.84, 95% CI 1.28-2.66) in their offspring. The association between maternal anxiety and children's eczema was mainly concentrated in the first 24 months, whereas the association with allergic rhinitis was mainly concentrated in the 36-48 months. CONCLUSION: Maternal anxiety during any trimester of pregnancy, especially with a consistently high trajectory of anxiety scores, was associated with higher odds of children's eczema and allergic rhinitis.

Sex-Specific Associations between Maternal Thyroid Peroxidase Antibodies and Cognitive Development in Preschool Children: A Prospective Cohort Study.

Background: An association between maternal thyroid dysfunction throughout pregnancy and the subsequent risk of neurodevelopmental abnormalities in offspring has been demonstrated. However, the potential effects of maternal thyroid autoimmunity on neurodevelopment in the absence of maternal hypothyroidism remain unclear. Therefore, in this study, we explored the association between maternal thyroid peroxidase antibody (TPOAb) positivity and cognitive development in preschool children. Methods: A total of 1849 mother-child pairs were recruited from the Ma'anshan Birth Cohort (MABC) Study. During the follow-up period, an electrochemiluminescence immunoassay was used to retrospectively measure serum TPOAb levels in pregnant women. The cognitive development of preschool children was evaluated by using the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition (WPPSI-IV). A growth mixture model was used to fit the trajectory of TPOAb. Multiple linear regression and logistic regression models were used to explore the associations between the developmental trajectory of TPOAb-positivity at different gestational periods and the cognitive development of preschool children by sex. Results: A total of 1849 mother-child pairs (mean [SD] age: 26.7 [3.6] years) were enrolled in the final study. Maternal TPOAb positivity in the first trimester was associated with a risk of below-average processing speed index in girls (OR: 2.07; 95% CI 1.06 to 4.01) and below-average full-scale intelligence quotient (FSIQ) in boys (OR: 2.36; 95% CI: 1.10 to 5.05). Maternal TPOAb positivity in the third trimester (T3) was associated with below-average working memory index (WMI) (OR: 2.51; 95% CI: 1.02 to 6.20) in girls. In girls, the WMI (ß = -3.17, 95% CI: -5.82 to -0.52), fluid reasoning index (FRI) (ß = -4.49, 95% CI: -7.18 to -1.80), and FSIQ score (ß = -2.43, 95% CI: -4.77 to -0.08) decreased, whereas in mothers, the level of log-transformed thyroid peroxidase antibody (lgTPOAb) increased during pregnancy. Conclusions: Positive maternal TPOAb levels during pregnancy may be associated with poorer cognitive development in preschool children. These findings require independent confirmation in other populations.

Impact of pregnancy-related anxiety on preschoolers' emotional and behavioral development: Gender specificity, critical time windows and cumulative effect.

BACKGROUND: Studies on the gender-specific effect of PrA on children's emotional and behavioral development are limited. Lack of PrA data on the entire pregnancy had caused difficulties in identifying the key time window and cumulative effects. METHODS: Based on Ma'anshan Birth Cohort in China, mothers at pregnancy and children followed up to 4 years of age were tested using the PrA questionnaire and the Achenbach Child Behavior Checklist (CBCL) 1.5-5. Finally, 1699 mother-child pairs were included in the study and regression models were developed for analysis. RESULTS: Children of mothers with PrA are at significantly elevated risk for abnormal mood/behavior at preschool age. Girls seemed to be more sensitive to maternal PrA than boys, mainly manifested in internalizing problems; The third trimester of pregnancy might be a critical time window when maternal PrA affected children's internalizing problems; Longer the duration women had PrA during pregnancy, more possibilities their children would have to develop internalizing and externalizing problems. LIMITATIONS: The PrA questionnaire may be different from PrA questionnaires in other countries such as due to different cultural contexts. Findings need to be interpreted with more caution. Factors such as maternal postpartum depression and care practices of nursing staff were not considered. No data were collected on disease as well as caregiver emotional status, which also impacts the reporting and identification of emotional/behavioral problems in children. CONCLUSIONS: Gender-specific and cumulative effect of PrA on preschoolers' emotional/behavioral development is observed. The third trimester of pregnancy might be the critical time window.

Peri-Conceptional Folic Acid Supplementation and Children's Physical Development: A Birth Cohort Study.

BACKGROUND: Maternal lack of folic acid supplementation during pregnancy may increase the risk of low birth weight and preterm delivery. However, little is known about the relationship between folic acid supplementation during pregnancy and the physical development of offspring in the later stage. OBJECTIVE: This study aimed to explore the association between maternal folic acid supplementation status during pregnancy and the physical development of preschool children. METHODS: A total of 3064 mother-child pairs with data on maternal folic acid supplementation status during pregnancy and children's anthropometric measurements were recruited from the Ma'anshan-Anhui Birth Cohort (MABC) in China. Maternal folic acid supplementation status during pregnancy was the main exposure, and the primary outcomes were children's growth development trajectories. Children's growth development trajectories were fitted using group-based trajectory models. The association between maternal folic acid supplementation status during pregnancy and children's growth trajectories was performed using multiple logistic regression models. RESULTS: After adjusting for potential confounders, we found that the absence of maternal folic acid supplementation before pregnancy and in the first trimester was significantly associated with a "high level" trajectory (trajectory 3) and a "high rising level" trajectory (trajectory 4) of BMI-Z scores in children 0 to 6 years of age (OR = 1.423, 95%CI:1.022-1.982; OR = 1.654, 95%CI: 1.024-2.671). In children aged 4 to 6 years old, a "high level" trajectory (trajectory 3) of body fat ratio was substantially related to maternal no folic acid supplementation before pregnancy and in the first trimester (OR = 1.833, 95%CI:1.037-3.240). No significant additional benefits associated with physical developmental indicators in preschool children have been observed with continued folic acid supplementation after the first trimester of gestation. CONCLUSIONS: Maternal non-supplementation with folic acid during pregnancy is associated with a "high level" BMI trajectory and a "high level" body fat ratio trajectory in preschool-aged children.

Maternal anxiety during pregnancy and children's asthma in preschool age: The Ma'anshan birth cohort study.

BACKGROUND: The fetal immune system and consequent elevated risk of asthma in childhood may be impacted by maternal anxiety during pregnancy. Limited studies have evaluated whether there was a sensitive period and cumulative effect of the relationship between prenatal anxiety and children's asthma. METHODS: 3131 mother-child pairs made up the study's sample from the Ma'anshan Birth Cohort Study in China. Maternal anxiety status was repeated three times using the pregnancy-related anxiety questionnaire in the 1st, 2nd and 3rd trimesters of pregnancy. Diagnostic information on asthma was collected three times at 24, 36, and 48 months of age. RESULTS: After adjusting for confounders, children born to mothers with anxiety in the 1st, 2nd and 3rd trimesters of pregnancy all had an elevated risk of total asthma from 12 to 48 months of age. After further adjusting prenatal anxiety in the other trimesters, no association was observed between prenatal anxiety in any trimester and preschoolers' asthma. Children of mothers with persistently high anxiety score trajectory during pregnancy had an elevated risk of total asthma and high prevalence trajectory of asthma. Cumulative effects analysis showed that the more frequent the mother's anxiety, the higher the risk of her offspring developing a high prevalence trajectory of asthma from 12 to 48 months of age. The results of the subgroup analysis by age showed similar associations overall. CONCLUSIONS: Maternal antenatal anxiety was associated with an elevated risk of preschool children's asthma, and a possible cumulative effect was observed. Maternal mental health conditions during pregnancy should receive constant attention throughout pregnancy, not just during one period.

Modeling of Polycrystalline Material Microstructure with 3D Grain Boundary Based on Laguerre-Voronoi Tessellation.

Voronoi tessellations are shown to be statistically representative of polycrystalline microstructures, which have been widely accepted for the modeling of microstructures of metallurgic and ceramic materials. In this paper, a new implementation of the Voronoi diagram in Laguerre geometry is presented for the generation of numerical models of polycrystalline microstructures, where the size and shape of the grains can be controlled, and the 3D grain boundaries can be modeled with a specified thickness. The distribution of grain sizes in the models is fitted to a lognormal distribution, compared with the normal distribution in the Voronoi tessellation methods. Finally, statistical analyses of grain face and grain size distribution are performed with the models, and the macroscopic elastic properties of polycrystalline ceramic materials are simulated to verify the capability of the presented method.

Maternal pre-pregnancy body mass index, gestational weight gain, and pubertal timing in daughters: A systematic review and meta-analysis of cohort studies.

The timing of daughter's puberty onset is constantly earlier. It is still unclear about the maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) as important prenatal factors that may affect offspring's onset of puberty. Thus, we evaluated the association among maternal pre-pregnancy BMI, GWG, and daughters' early pubertal development based on the existing literature. Literature review was conducted in different databases, including Web of Science, Pubmed, Wiley, ScienceDirect, Web of Science, and Chinese National Knowledge Infrastructure databases up to June 2021. We selected random effects model or fixed effects model for meta-analysis according to the I2 statistics value to obtain the summary measurement. A total of 12 cohort studies were included. Compared to maternal pre-pregnancy normal weight, maternal pre-pregnancy overall overweight/obesity (RR = 1.24; 95% CI 1.17 to 1.32), obesity (RR = 1.35; 95% CI 1.23 to 1.48), and overweight (RR = 1.17; 95% CI 1.09 to 1.26) were significantly associated with the increased risk of earlier timing of pubertal onset in daughters. Daughters born of mothers with pre-pregnancy overall overweight/obesity, obesity, and overweight had earlier pubertal onset compared to those born of mothers with normal weight ([mean difference = -3.03, 95% CI: -3.97 to -2.10], [mean difference = -3.50, 95% CI: -5.38 to -1.62], and [mean difference = -2.89, 95% CI: -4.07 to -1.71], respectively). The effects were also significant in the assessed three milestones (menarche, breast development, and pubic hair development). Maternal excessive GWG increased the risk of early pubertal timing in daughters (RR = 1.19; 95% CI 1.09 to 1.30).

Sex-specific association between elective cesarean section and growth trajectories in preschool children: A prospective birth cohort study.

Background: Elective cesarean section (ECS) primarily contributes to the rising cesarean section (CS) rate, and much attention has been attracted to its health consequences. The association between ECS and overweight and obesity in children has been controversial, and few studies distinguished ECS with medical indications from those without indications. Based on a large sample birth cohort, we aim to examine the association of ECS with or without medical indications on children's physical development by using repeated anthropometric data from birth to 6 years of age. Methods: A total of 2304 mother-child pairs with complete data on delivery mode and children's anthropometric measurements were recruited from the Ma'anshan-Anhui Birth Cohort (MABC) in China. ECS was the main exposure in this study, and the primary outcomes were children's growth trajectories and early adiposity rebound (AR). Children's BMI trajectories were fitted by using group-based trajectory models and fractional polynomial mixed-effects models. The association between ECS and children's growth trajectories and early AR was performed using multiple logistic regression models. Results: Among 2,304 mother-child pairs (1199 boys and 1105 girls), 1088 (47.2%) children were born by CS, including 61 (5.6%) emergency CS, 441 (40.5%) ECS with medical indications, and 586 (53.9%) ECS without medical indications. After adjusting for potential confounders, it was found that ECS with medical indications was associated with a "high level" of BMI trajectory (OR = 1.776; 95% CI: 1.010-3.123), and ECS without medical indications was associated with early AR (OR = 1.517; 95% CI: 1.123-2.050) in girls. In boys, we found that ECS without medical indications was unlikely to experience an accelerated growth trajectory (OR = 0.484; 95%CI: 0.244-0.959). Conclusions: ECS may be related to girls' "high level" BMI trajectories and early AR. If causal, the findings will provide an evidence-based reference for early life interventions for childhood obesity.