Birth weight and risk of type 2 diabetes: a systematic review

Evaluating the Concept of Brain Sparing in a High Income Setting, Using Historical Records of Maternal Influenza or Syphilis Infection

INTRODUCTION

In the context of adverse in utero environments, the fetal brain might be preserved at the expense of other tissues. This trade-off, brain sparing, has not been studied in the context of maternal infection. We investigated cases of maternal syphilis in the early 20th century and influenza during the 1918-1920 pandemic, in the Swiss city of Lausanne, a relatively high-income setting. We tested the brain sparing hypothesis, that head circumference is protected at the expense of birth weight.

METHODS

A total of 8530 individual birth records from 1911 to 1922 from the University Maternity Hospital of Lausanne were used. We fitted generalized linear and additive linear models to explain how neonatal size varies under disease exposure.

RESULTS

Influenza reduced head circumference and birth weight among livebirths similarly, by -0.11 and -0.14 standard deviation (SD) units respectively. Conversely, for syphilis-exposed infants, head circumference was affected more than birth weight (-0.61 SD vs. -0.46 SD). Stillborn infants exposed to syphilis experienced a much greater reduction in head circumference (-1.92 SD) than liveborn infants. After adjustment for gestational age, these findings persisted in the case of influenza, but the effects of syphilis were reduced. Furthermore, half of syphilis-exposed infants were born before term, suggesting that lower infant size was partly mediated by shorter gestation. Nevertheless, head circumference among stillbirths exposed to syphilis was still substantially reduced, even after adjustment for gestational age (-1.26 SD).

CONCLUSION

Our findings do not support the brain sparing hypothesis. Moreover, the substantial reduction in head circumference among syphilis-exposed fetuses might help explain why a quarter of them were stillborn.

Longitudinal study of birthweight, blood pressure, and markers of arterial stiffness in children age six among the TIDES cohort

OBJECTIVE

Although some studies have observed an association between birthweight and cardiovascular disease in adulthood, fewer have investigated whether birthweight is linked to cardiovascular health in early childhood. This study assesses the association between birthweight and cardiovascular outcomes in children 6 years of age.

STUDY DESIGN

Birthweight, blood pressure (BP), and markers of arterial stiffness in children, including brachial artery distensibility and carotid-femoral pulse wave velocity (cfPWV), were obtained from 324 participants in The Infant Development and the Environment Study, a prospective multisite pregnancy cohort. Birthweight was converted into sex-specific birthweight-for-gestational-age (bw/ga) z -scores based on the INTERGROWTH-21st standard. Following 2017 American Academy of Pediatrics guidelines, SBP and DBP were transformed into sex, age, and height-specific z -scores. Associations between birthweight and cardiovascular outcomes were assessed using nested multivariable linear regression models among the overall and sex-stratified samples.

RESULTS

Among the overall sample, bw/ga z -score was positively associated with cfPWV [b = 0.11 m/s, 95% confidence interval (CI): 0.01 m/s, 0.21 m/s] in crude and adjusted models. No associations between birthweight and cardiovascular outcomes were detected among the sex-stratified analyses.

CONCLUSION

Overall, birthweight was not related to cardiovascular outcomes in children 6 years old. However, infants born with a higher birthweight may be at risk for higher cfPWV in childhood. Early intervention in pregnant people at risk of delivering high birthweight infants may be warranted if results are replicated.

Association between birth weight/joint exposure to ambient air pollutants and type 2 diabetes: a cohort study in the UK Biobank

Early life events and environmental factors are associated with type 2 diabetes (T2D) development. We assessed the combined effect of birth weight andambient air pollutants, and effect of their interaction on T2D risk. Totally, 6,474 T2D incidents were recorded over an 8.7-year follow-up period. The adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) were 1.31 (1.26, 1.36) for each kilogram decrease in birth weight, and 1.08 (1.05, 1.11) for each standard deviation increase in air pollution score (APS). Birth weight<3000 g amplified the T2D risk associated with high APS. A combination of the lowest birth weight (<2500 g) and the highest quintile of APS led to over two-fold increase in T2D risk (aHR: 2.17; 95% CI: 1.79-2.64). There was a significant additive interaction between them. In conclusion, ambient air pollutants increase the risk for T2D, particularly in populations with low birth weight.

Comprehensive Analysis of Placental DNA Methylation Changes and Fetal Birth Weight in Pigs

Birth weight is a complex multifactorial trait relevant to health states and disease risks in later life. The placenta is essential for proper fetal growth and facilitates gas, nutrient, and waste exchange between the mother and developing fetus. How changes in placental DNA methylation affect fetal birth weight remains to be fully elucidated. In this study, we used whole-genome bisulfite sequencing and RNA sequencing to reveal a global map of DNA methylation and gene expression changes between the placentas of highest birth weight and lowest birth weight piglets in the same litters. The transcriptome analysis identified 1682 differential expressed genes and revealed key transcriptional properties in distinct placentas. We also identified key transcription factors that may drive the differences in DNA methylome patterns between placentas. The decrease in DNA methylation level in the promoter was associated with the transcriptional activation of genes associated with angiogenesis, extracellular matrix remodeling, and transmembrane transport. Our results revealed the regulatory role of DNA methylation in gene transcription activity leading to the differences in placental morphological structures and birth weights of piglets. These results could provide novel clues to clarify the underlying regulatory mechanisms of placental development and fetal growth.

Prenatal exposure to multiple environmental chemicals and birth size

BACKGROUND

Epidemiological studies addressing the combined effects of exposure to chemical mixtures at different stages of pregnancy on birth size are scarce.

OBJECTIVE

To evaluate the association between prenatal exposure to chemical mixtures and birth size.

METHODS

Our previous study repeatedly measured the urinary concentrations of 34 chemical substances among 743 pregnant women and identified three distinct clusters of exposed population and six dominant principal components of exposed chemicals in each trimester. In this study, we assessed the associations of these exposure profiles with birth weight, birth length, and ponderal index using multivariable linear regression.

RESULTS

We found that compared with women in cluster 1 (lower urinary chemical concentrations), women in cluster 2 (higher urinary concentrations of metals, benzothiazole, benzotriazole, and some phenols), and women in cluster 3 (higher urinary concentrations of phthalates) were more likely to give birth to children with higher birth length [0.23 cm (95% CI: -0.03, 0.49); 0.29 cm (95%CI: 0.03, 0.54), respectively]. This association was observed only in 1st trimester. In addition, prenatal exposure to PC3 (higher benzophenones loading) was associated with reduced birth length across pregnancy [-0.07 cm (95% CI: -0.18, 0.03) in 1st and 2nd trimester; -0.13 cm (95% CI: -0.24, -0.03) in 3rd trimester]. Exposure to PC6 (higher thallium and BPA loading in 2nd trimester) was associated with increased birth length [0.15 cm (95% CI: 0.05, 0.26)]. Compared with other outcomes, associations of both clusters and PCs with birth length were stronger, and these associations were more pronounced in boys.

IMPACT STATEMENT

Exposure to multiple chemicals simultaneously, the actual exposure situation of pregnant women, was associated with birth size, indicating that chemical mixtures should be taken more seriously when studying the health effects of pollutants.

Association of cord plasma metabolites with birth weight: results from metabolomic and lipidomic studies of discovery and validation cohorts

OBJECTIVE

Birth weight is a good predictor of fetal intrauterine growth and long-term health, and several studies have evaluated the relationship between metabolites and birth weight. The aim of this study was to investigate the association of cord blood metabolomics and lipidomics with birth weight, using a two-stage discovery and validation approach.

METHODS

Firstly, a pseudotargeted metabolomics approach was applied to detect metabolites in 504 cord blood samples in the discovery set enrolled from the Wuhan Healthy Baby Cohort, China. Metabolome-wide association scan analysis and pathway enrichment were applied to identify metabolites and metabolic pathways that were significantly associated with birth weight adjusted for gestational age Z-score (BW Z-score). Logistic regression models were used to analyze the association of metabolites in the most significantly associated pathways with small-for-gestational age (SGA) at delivery and low birth weight (LBW). Subsequently, 350 cord blood samples in a validation cohort were subjected to targeted analysis to validate the metabolites identified by screening in the discovery cohort.

RESULTS

In the discovery set, of 2566 metabolites detected, 2418 metabolites were retained for subsequent analysis after data preprocessing. Of these, 513 metabolites were significantly associated with BW Z-score (P-value adjusted for false discovery rate (PFDR) < 0.05), of which 298 Kyoto Encyclopedia of Genes and Genomes (KEGG)-annotated metabolites were included in the pathway analysis. The primary bile acid biosynthesis pathway was the most relevant metabolic pathway associated with BW Z-score. Elevated cord plasma primary bile acids were associated with lower BW Z-score and higher risk of SGA or LBW in the discovery and validation cohorts. In the validation set, a 2-fold increase in taurochenodeoxycholic acid (TCDCA) and in taurocholic acid (TCA) was associated with a decrease in BW Z-score (estimated β coefficient, -0.10 (95% CI, -0.20 to 0.00) and -0.18 (95% CI, -0.31 to -0.04), respectively), after adjusting for covariates. In addition, a 2-fold increase in cord plasma TCDCA and of cord plasma TCA was associated with an increased risk of SGA (adjusted odds ratio (OR), 1.52 (95% CI, 1.00-2.30) and 1.77 (95% CI, 1.05-2.98), respectively). The adjusted OR for LBW, for a 2-fold increase in TCDCA and TCA concentration, were 2.39 (95% CI, 1.00-5.71) and 3.21 (95% CI, 0.96-10.74), respectively.

CONCLUSIONS

These results indicate a significant association of elevated primary bile acids, particularly TCDCA and TCA, in cord blood with lower BW Z-score, as well as increased risk of SGA and LBW. Abnormalities of primary bile acid metabolism may play an important role in restricted fetal development. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Association between infant birth weight and gestational weight gain in Japanese women with diabetes mellitus

AIMS/INTRODUCTION

In 2021, the guidelines on gestational weight gain (GWG) were revised and increased by 2-3 kg in Japan. This study aimed to investigate whether the revised guidelines would increase the incidence of babies with excessive birth weight in mothers with diabetes.

MATERIALS AND METHODS

This retrospective study included 369 deliveries of women with diabetes whose pre-pregnancy body mass index was below 30 kg/m2 between 1982 and 2021. The primary outcome measure was large for gestational age (LGA). We compared the incidence of LGA between women who gained weight within the previous guidelines and women who gained weight within the revised guidelines. We also compared the incidence of macrosomia, preeclampsia, small for gestational age (SGA), and low birth weight.

RESULTS

The incidence of LGA was not significantly different between women who gained weight within the revised guidelines and those within the previous guidelines (34.6% [95% confidence interval 25.6-44.6%] for the revised guidelines vs 28.9% [21.6-37.1%] for the previous guidelines; P = 0.246). Neither was the incidence of macrosomia or preeclampsia significantly different (8.7% [4.0-15.8%] vs 5.6% [2.5-10.8%] and 5.8% [2.1-12.1%] vs 6.3% [2.9-11.7%]; P = 0.264 and 0.824, respectively), while women who gained weight within the revised guidelines had a lower incidence of SGA (1.9% [0.2-6.8%] vs 10.6% [6.0-16.8%]; P = 0.001) and low birth weight (1.0% [0.02-5.2%] vs 7.0% [3.4-12.6%]; P = 0.023).

CONCLUSIONS

The revised GWG guidelines could be beneficial in women with diabetes in terms of delivering babies with appropriate birth weight.

Reproductive chemical database: a curated database of chemicals that modulate protein targets regulating important reproductive biological processes

Recent studies have shifted the spotlight from adult disease to gametogenesis and embryo developmental events, and these are greatly affected by various environmental chemicals, such as drugs, metabolites, pollutants, and others. Growing research has highlighted the critical importance of identifying and understanding the roles of chemicals in reproductive biology. However, the functions and mechanisms of chemicals in reproductive processes remain incomplete. We developed a comprehensive database called the Reproductive Chemical Database (RCDB) ( https://yu.life.sjtu.edu.cn/ChenLab/RCDB ) to facilitate research on chemicals in reproductive biology. This resource is founded on rigorous manual literature extraction and precise protein target prediction methodologies. This database focuses on the delineation of chemicals associated with phenotypes, diseases, or endpoints intricately associated with four important reproductive processes: female and male gamete generation, fertilization, and embryo development in human and mouse. The RCDB encompasses 93 sub-GO processes, and it revealed 1447 intricate chemical-biological process interactions. To date, the RCDB has meticulously cataloged and annotated 830 distinct chemicals, while also predicting 614 target proteins from a selection of 3800 potential candidates. Additionally, the RCDB offers an online predictive tool that empowers researchers to ascertain whether specific chemicals play discernible functional roles in these reproductive processes. The RCDB is an exhaustive, cross-platform, manually curated database, which provides a user-friendly interface to search, browse, and use reproductive processes modulators and their comprehensive related information. The RCDB will help researchers to understand the whole reproductive process and related diseases and it has the potential to promote reproduction research in the pharmacological and pathophysiological areas.

Interaction effect between low birthweight and resistin gene rs1862513 variant on insulin resistance and type 2 diabetes mellitus in adulthood: Toon Genome Study

AIMS/INTRODUCTION

Gene-environment interactions are considered to critically influence type 2 diabetes mellitus development; however, the underlying mechanisms and specific interactions remain unclear. Given the increasing prevalence of low birthweight (LBW) influenced by the intrauterine environment, we sought to investigate genetic factors related to type 2 diabetes development in individuals with LBW.

MATERIALS AND METHODS

The interaction between 20 reported type 2 diabetes susceptibility genes and the development of type 2 diabetes in LBW (<2,500 g) individuals in a population-based Japanese cohort (n = 1,021) was examined by logistic regression and stratified analyses.

RESULTS

Logistic regression analyses showed that only the G/G genotype at the rs1862513 locus of the resistin gene (RETN), an established initiator of insulin resistance, was closely related to the prevalence of type 2 diabetes in individuals with LBW. Age, sex and current body mass index-adjusted stratified analyses showed a significant interaction effect of LBW and the RETN G/G genotype on fasting insulin, homeostatic model assessment 2-insulin resistance, Matsuda index and the prevalence of type 2 diabetes (all P-values for interaction <0.05). The adjusted odds ratio for type 2 diabetes in the LBW + G/G genotype group was 7.33 (95% confidence interval 2.43-22.11; P = 0.002) compared with the non-LBW + non-G/G genotype group. Similar results were obtained after excluding the influence of malnutrition due to World War II.

CONCLUSIONS

Simultaneous assessment of LBW and the RETN G/G genotype can more accurately predict the risk of future type 2 diabetes than assessing each of these factors alone, and provide management strategies, including early lifestyle intervention in LBW population.

Maternal birth weight is an indicator of preterm delivery: the Japan environment and children's study

This study aimed to investigate the association between maternal birth weight (MBW) with preterm delivery (PTD) in the Japanese population. To this end, a total of 78,972 Japanese pregnant women were included in a prospective birth cohort study. Multiple logistic regression and multinominal logistic regression models were applied to investigate the associations of MBW with PTD (delivery from 22 to < 37 weeks of gestation), early PTD (delivery from 22 to < 34 weeks), and late PTD (delivery from 34 to < 37 weeks). The results showed that MBW was inversely associated with PTD, early PTD, and late PTD (p-for-trend < 0.0001, 0.0014, and < 0.0001, respectively). The adjusted odds ratios per each 500 g of MBW decrease were 1.167 (95% confidence interval [CI]: 1.118-1.218) for PTD, 1.174 (95% CI: 1.070-1.287) for early PTD and 1.151 (95% CI: 1.098-1.206) for late PTD. The effect size of the association of MBW with early PTD was similar to that with late PTD. This study demonstrated for the first time an association of a low MBW with PTD, early PTD, and late PTD in a Japanese nationwide cohort.

Associations of birth weight, plasma metabolome in adulthood and risk of type 2 diabetes

AIMS

We aimed to examine the longitudinal associations of birth weight with plasma metabolites in adulthood, and further quantify the proportions of the links between birth weight and incident adult type 2 diabetes (T2D) that were mediated by plasma metabolites.

MATERIALS AND METHODS

A total of 62,033 participants with complete nuclear magnetic resonance metabolomics and birth weight data from the UK Biobank were included in this study. Linear regression was used to assess the associations between birth weight and metabolites. Cox regression was used to estimate hazard ratios for T2D associated with metabolites. We further performed mediation analyses to estimate the extent to which metabolites might mediate the association between birth weight and T2D risk.

RESULTS

Low birth weight was associated with the adverse metabolic responses across multiple metabolic pathways, including lipoprotein subclasses, amino acids, fatty acids (FA), and inflammation. Metabolites associated with higher birth weight tended to be associated with a lower risk of T2D (Pearson correlation coefficient: -0.85). A total of 62 metabolites showed statistically significant mediation effects in the protective association of higher birth weight and T2D risk, including large-sized very low-density lipoprotein particles and triglyceride concentrations as well as saturated, and monounsaturated FA and glycoprotein acetyls.

CONCLUSIONS

We identified a range of metabolites that reflect the adult metabolic response to birth weight, some of which might lie on the pathway between birth weight and adult T2D risk.

Low birthweight and overweight during childhood and young adulthood and the risk of type 2 diabetes in men: a population-based cohort study

AIMS/HYPOTHESIS

This study aimed to determine the relative contributions of low birthweight and overweight during childhood and young adulthood to the risk of type 2 diabetes in men.

METHODS

We included 34,231 men born between1945 and 1961 from the population-based BMI Epidemiology Study (BEST) Gothenburg with data on birthweight and overweight status in childhood (8 years, BMI >17.9 kg/m2) and young adulthood (20 years, BMI >25 kg/m2). Participants were followed from age 30 years until 31 December 2019. Information on type 2 diabetes diagnoses was retrieved from Swedish national registers. HRs and 95% CIs for the risk of early (≤59.4 years) and late (>59.4 years) type 2 diabetes were estimated using Cox proportional hazards regression.

RESULTS

During follow-up, a total of 2733 cases of type 2 diabetes were diagnosed. Birthweight below the median (<3.6 kg) and overweight at age 20 (BMI >25 kg/m2), but not overweight at age 8 (BMI >17.9 kg/m2), were associated with an increased risk of early and late type 2 diabetes. Of note, a birthweight below the median followed by overweight at age 20 years was associated with a substantially increased risk of early type 2 diabetes (HR 6.07, 95% CI 5.08, 7.27), and a low birthweight (≤2.5 kg) combined with overweight at age 20 years was associated with a massive risk of early type 2 diabetes (HR 9.94, 95% CI 6.57, 15.05).

CONCLUSIONS/INTERPRETATION

Low birthweight and overweight in young adulthood are the major developmental determinants of adult type 2 diabetes risk in men. They contribute in an additive manner to the risk of type 2 diabetes. To reduce the risk of type 2 diabetes, young adult overweight should be avoided, especially in boys with a low birthweight.

DATA AVAILABILITY

The SPSS analysis code, the R analysis code and a data dictionary have been made available in an online repository ( https://osf.io/bx2as/ ).

Association between birth weight and insulin resistance in US adolescents: A retrospective cohort study exploring the role of concurrent body mass index

BACKGROUND AND AIMS

This study aimed to investigate the association between birth weight (BW) and abnormal HOMA-IR in US adolescents aged 12-15 years. The role of concurrent body mass index (BMI) in adolescence was also examined.

METHODS AND RESULTS

This retrospective cohort study included 3429 participants from NHANES with data in 1999-2020. HOMA-IR ≥2.3 was considered abnormal. Participants were classified as low (LBW; <2.5 kg), normal (NBW; 2.5-4.0 kg), or high (HBW; >4.0 kg) BW. Logistic regression was used to explore the association between BW and HOMA-IR. Mediation analysis was used to examine whether BMI z-score in adolescence mediated the association between BW and HOMA-IR. Compared with those in NBW, the odds ratios (95 % CI) of abnormal HOMA-IR in LBW and HBW groups were 1.26 (0.99-1.60), and 0.62 (0.47-0.83) respectively. The association between BW and abnormal HOMA-IR was consistent in all subgroups with no significant interactions. Mediation analysis showed that BW is associated with lower risk of HOMA-IR directly, but with higher risk indirectly via BMI in adolescence.

CONCLUSION

There was a negative linear relationship between BW and the prevalence of abnormal HOMA-IR in adolescents aged 12-15 independent of concurrent BMI. Children who were born with LBW but had high BMI in adolescence were of particularly higher risk of insulin resistance.

Appropriate glycemic management protects the germline but not the uterine environment in hyperglycemia

Emerging evidence indicates that parental diseases can impact the health of subsequent generations through epigenetic inheritance. Recently, it was shown that maternal diabetes alters the metaphase II oocyte transcriptome, causing metabolic dysfunction in offspring. However, type 1 diabetes (T1D) mouse models frequently utilized in previous studies may be subject to several confounding factors due to severe hyperglycemia. This limits clinical translatability given improvements in glycemic control for T1D subjects. Here, we optimize a T1D mouse model to investigate the effects of appropriately managed maternal glycemic levels on oocytes and intrauterine development. We show that diabetic mice with appropriate glycemic control exhibit better long-term health, including maintenance of the oocyte transcriptome and chromatin accessibility. We further show that human oocytes undergoing in vitro maturation challenged with mildly increased levels of glucose, reflecting appropriate glycemic management, also retain their transcriptome. However, fetal growth and placental function are affected in mice despite appropriate glycemic control, suggesting the uterine environment rather than the germline as a pathological factor in developmental programming in appropriately managed diabetes.

Family cash transfers in childhood and birthing persons and birth outcomes later in life

Much literature in the US documents an intergenerational transmission of birthing person and perinatal morbidity in socioeconomically disadvantaged groups. A separate line of work indicates that family cash transfers may improve life chances of low-income families well into adulthood. By exploiting a quasi-random natural experiment of a large family cash transfer among a southeastern American Indian (AI) tribe in rural North Carolina, we examine whether a "perturbation" in socioeconomic status during childhood improves birthing person/perinatal outcomes when they become parents themselves. We acquired birth records on 6805 AI and non-AI infants born from 1995 to 2018. Regression methods to examine effect modification tested whether the birthing person's American Indian (AI) status and exposure to the family cash transfer during their childhood years corresponds with improvements in birthing person and perinatal outcomes. Findings show an increase in age at childbearing (coef: 0.15 years, 95% confidence interval [CI]: 0.05, 0.25) and a decrease in pre-pregnancy body mass index (BMI; coef: -0.42, 95% CI: -0.76, -0.09) with increased duration of cash transfer exposure during childhood. The odds of large-for-gestational age at delivery, as well as mean infant birthweight, is also reduced among AI births whose birthing person had relatively longer duration of exposure to the cash transfer. We, however, observe no relation with other birthing person/perinatal outcomes (e.g., tobacco use during pregnancy, preterm birth). In this rural AI population, cash transfers in one generation correspond with improved birthing person and infant health in the next generation.

Maternal plasma cortisol's effect on offspring birth weight: a Mendelian Randomisation study

BACKGROUND

Observational studies and randomized controlled trials have found evidence that higher maternal circulating cortisol levels in pregnancy are associated with lower offspring birth weight. However, it is possible that the observational associations are due to residual confounding.

METHODS

We performed two-sample Mendelian Randomisation (MR) using a single genetic variant (rs9989237) associated with morning plasma cortisol (GWAS; sample 1; N = 25,314). The association between this maternal genetic variant and offspring birth weight, adjusted for fetal genotype, was obtained from the published EGG Consortium and UK Biobank meta-analysis (GWAS; sample 2; N = up to 406,063) and a Wald ratio was used to estimate the causal effect. We also performed an alternative analysis using all GWAS reported cortisol variants that takes account of linkage disequilibrium. We also tested the genetic variant's effect on pregnancy cortisol and performed PheWas to search for potential pleiotropic effects.

RESULTS

The estimated effect of maternal circulating cortisol on birth weight was a 50 gram (95% CI, -109 to 10) lower birth weight per 1 SD higher log-transformed maternal circulating cortisol levels, using a single variant. The alternative analysis gave similar results (-33 grams (95% CI, -77 to 11)). The effect of the cortisol variant on pregnancy cortisol was 2-fold weaker than in the original GWAS, and evidence was found of pleiotropy.

CONCLUSIONS

Our findings provide some evidence that higher maternal morning plasma cortisol causes lower birth weight. Identification of more independent genetic instruments for morning plasma cortisol are necessary to explore the potential bias identified.

Methylation Status of IGF-Axis Genes in the Placenta of South Indian Neonates with Appropriate and Small for Gestational Age

OBJECTIVE

Altered methylation patterns of insulin-like growth factor (IGF)-axis genes in small for gestational age (SGA) have been reported in different populations. In the present study, we analyzed the methylation status of IGF-axis genes in the placenta of appropriate for gestational age (AGA) and SGA neonates of South Indian women.

METHODS

Placental samples were collected from AGA (n = 40) and SAG (n = 40) neonates. The methylation of IGF-axis genes promoter was analyzed using MS-PCR.

RESULTS

IGF2, H19, IGF1, and IGFR1 genes promoter methylation was 2.5, 1.5, 5, and 7.5% lower in SGA compared to AGA, respectively. Co-methylation of IGF-axis genes promoter was 40% and 20% in AGA and SGA, respectively. IGF-axis gene promoter methylation significantly (p < 0.05) influenced the levels of IGFBP3 protein, birth weight, mitotic index, gestational weeks, and IGFR1 and IGFR2 gene expression.

CONCLUSION

IGF-axis genes methylation was lower in SGA than in AGA, and the methylation significantly influenced the IGF-axis components.

Birthweight, genetic risk, and gastrointestinal cancer incidence: a prospective cohort study

BACKGROUND

The epidemiologic studies investigating the association of birthweight and genetic factors with gastrointestinal cancer remain scarce. The study aimed to prospectively assess the interactions and joint effects of birthweight and genetic risk levels on gastrointestinal cancer incidence in adulthood.

METHODS

A total of 254,997 participants were included in the UK Biobank study. We used multivariate restricted cubic splines and Cox regression models to estimate the hazard ratios (HRs) and 95% confidential intervals (CI) for the association between birthweight and gastrointestinal cancer risk, then constructed a polygenic risk score (PRS) to assess its interaction and joint effect with birthweight on the development of gastrointestinal cancer.

RESULTS

We documented 2512 incident cases during a median follow-up of 8.88 years. Compare with participants reporting a normal birthweight (2.5-4.5 kg), multivariable-adjusted HR of gastrointestinal cancer incidence for participants with high birthweight (≥4.5 kg) was 1.17 (95%CI: 1.01-1.36). Such association was remarkably observed in pancreatic cancer, with an HR of 1.82 (95%CI: 1.26-2.64). No statistically significant association was observed between low birth weight and gastrointestinal cancers. Participants with high birthweight and high PRS had the highest risk of gastrointestinal cancer (HR: 2.95, 95%CI: 2.19-3.96).

CONCLUSION

Our findings highlight that high birthweight is associated with a higher incidence of gastrointestinal cancer, especially for pancreatic cancer. Benefits would be obtained from birthweight control, particularly for individuals with a high genetic risk.KEY MESSAGESThe epidemiologic studies investigating the association of birthweight and genetic factors with gastrointestinal cancer remain scarce.This cohort study of 254,997 adults in the United Kingdom found an association of high birthweight with the incidence of gastrointestinal cancer, especially for pancreatic cancer, and also found that participants with high birthweight and high polygenic risk score had the highest risk of gastrointestinal cancer.Our data suggests a possible effect of in utero or early life exposures on adulthood gastrointestinal cancer, especially for those with a high genetic risk.

Cardiovascular Risk in Pediatrics: A Dynamic Process during the First 1000 Days of Life

The early childhood period, encompassing prenatal and early stages, assumes a pivotal role in shaping cardiovascular risk factors. We conducted a narrative review, presenting a non-systematic summation and analysis of the available literature, focusing on cardiovascular risk from prenatal development to the first 1000 days of life. Elements such as maternal health, genetic predisposition, inadequate fetal nutrition, and rapid postnatal growth contribute to this risk. Specifically, maternal obesity and antibiotic use during pregnancy can influence transgenerational risk factors. Conditions at birth, such as fetal growth restriction and low birth weight, set the stage for potential cardiovascular challenges. To consider cardiovascular risk in early childhood as a dynamic process is useful when adopting a personalized prevention for future healthcare and providing recommendations for management throughout their journey from infancy to early adulthood. A comprehensive approach is paramount in addressing early childhood cardiovascular risks. By targeting critical periods and implementing preventive strategies, healthcare professionals and policymakers can pave the way for improved cardiovascular outcomes. Investing in children's health during their early years holds the key to alleviating the burden of cardiovascular diseases for future generations.

Hormonal Determinants of Growth and Weight Gain in the Human Fetus and Preterm Infant

The factors controlling linear growth and weight gain in the human fetus and newborn infant are poorly understood. We review here the changes in linear growth, weight gain, lean body mass, and fat mass during mid- and late gestation and the early postnatal period in the context of changes in the secretion and action of maternal, placental, fetal, and neonatal hormones, growth factors, and adipocytokines. We assess the effects of hormonal determinants on placental nutrient delivery and the impact of preterm delivery on hormone expression and postnatal growth and metabolic function. We then discuss the effects of various maternal disorders and nutritional and pharmacologic interventions on fetal and perinatal hormone and growth factor production, growth, and fat deposition and consider important unresolved questions in the field.

Low birthweight is associated with a higher incidence of type 2 diabetes over two decades independent of adult BMI and genetic predisposition

AIMS/HYPOTHESIS

Low birthweight is a risk factor for type 2 diabetes. Most previous studies are based on cross-sectional prevalence data, not designed to study the timing of onset of type 2 diabetes in relation to birthweight. We aimed to examine associations of birthweight with age-specific incidence rate of type 2 diabetes in middle-aged to older adults over two decades.

METHODS

Adults aged 30-60 years enrolled in the Danish Inter99 cohort in 1999-2001 (baseline examination), with information on birthweight from original birth records from 1939-1971 and without diabetes at baseline, were eligible. Birth records were linked with individual-level data on age at diabetes diagnosis and key covariates. Incidence rates of type 2 diabetes as a function of age, sex and birthweight were modelled using Poisson regression, adjusting for prematurity status at birth, parity, polygenic scores for birthweight and type 2 diabetes, maternal and paternal diabetes history, socioeconomic status and adult BMI.

RESULTS

In 4590 participants there were 492 incident type 2 diabetes cases during a mean follow-up of 19 years. Type 2 diabetes incidence rate increased with age, was higher in male participants, and decreased with increasing birthweight (incidence rate ratio [95% CI per 1 kg increase in birthweight] 0.60 [0.48, 0.75]). The inverse association of birthweight with type 2 diabetes incidence was statistically significant across all models and in sensitivity analysis.

CONCLUSIONS/INTERPRETATION

A lower birthweight was associated with increased risk of developing type 2 diabetes independent of adult BMI and genetic risk of type 2 diabetes and birthweight.

Fitness of INTERGROWTH-21st birth weight standards for Chinese-ethnicity babies

OBJECTIVE

To determine the fitness of the INTERGROWTH-21st birth weight standards (INTERGROWTH21) for ethnic Chinese babies compared with a local reference (FOK2003).

DESIGN

Population-based analysis of territory-wide birth data.

SETTING

All public hospitals in Hong Kong.

PARTICIPANTS

Live births between 24 and 42 complete weeks' gestation during 2006-2017.

MAIN OUTCOME MEASURES

Babies' birth weight Z-scores were calculated using published methods. The two references were compared in three aspects: (1) the proportions of large-for-gestational-age (LGA) or small-for-gestational-age (SGA) infants, (2) the gestation-specific and sex-specific mean birth weight Z-scores and (3) the predictive power for SGA-related complications.

RESULTS

488 896 infants were included. Using INTERGROWTH21, among neonates born <33 weeks' gestation, the mean birth weight Z-scores per week were closer to zero (-0.2 to 0.05), while most of them were further from zero (0.06 to 0.34) after excluding infants with a high risk of abnormal intrauterine growth. Compared with FOK2003, INTERGROWTH21 classified smaller proportions of infants as SGA (8.3% vs 9.6%) and LGA (6.6% vs 7.9%), especially SGA among preterm infants (13.1% vs 17.0%). The area under the receiver operating characteristic curve for predicting SGA-related complications was greater with FOK2003 (0.674, 95% CI 0.670 to 0.677) than INTERGROWTH21 (0.658, 95% CI 0.655 to 0.661) (p<0.001).

CONCLUSIONS

INTERGROWTH21 performed less well than FOK2003, a local reference for ethnic Chinese babies, especially in infants born <33 weeks' gestation. Although the differences are clinically small, both these references performed poorly for extremely preterm infants, and thus a more robust chart based on a larger sample of appropriately selected infants is needed.

Birthweight is associated with clinical characteristics in people with recently diagnosed type 2 diabetes

AIMS/HYPOTHESIS

Low birthweight is a risk factor for type 2 diabetes but it is unknown whether low birthweight is associated with distinct clinical characteristics at disease onset. We examined whether a lower or higher birthweight in type 2 diabetes is associated with clinically relevant characteristics at disease onset.

METHODS

Midwife records were traced for 6866 individuals with type 2 diabetes in the Danish Centre for Strategic Research in Type 2 Diabetes (DD2) cohort. Using a cross-sectional design, we assessed age at diagnosis, anthropomorphic measures, comorbidities, medications, metabolic variables and family history of type 2 diabetes in individuals with the lowest 25% of birthweight (<3000 g) and highest 25% of birthweight (>3700 g), compared with a birthweight of 3000-3700 g as reference, using log-binomial and Poisson regression. Continuous relationships across the entire birthweight spectrum were assessed with linear and restricted cubic spline regression. Weighted polygenic scores (PS) for type 2 diabetes and birthweight were calculated to assess the impact of genetic predispositions.

RESULTS

Each 1000 g decrease in birthweight was associated with a 3.3 year (95% CI 2.9, 3.8) younger age of diabetes onset, 1.5 kg/m2 (95% CI 1.2, 1.7) lower BMI and 3.9 cm (95% CI 3.3, 4.5) smaller waist circumference. Compared with the reference birthweight, a birthweight of <3000 g was associated with more overall comorbidity (prevalence ratio [PR] for Charlson Comorbidity Index Score ≥3 was 1.36 [95% CI 1.07, 1.73]), having a systolic BP ≥155 mmHg (PR 1.26 [95% CI 0.99, 1.59]), lower prevalence of diabetes-associated neurological disease, less likelihood of family history of type 2 diabetes, use of three or more glucose-lowering drugs (PR 1.33 [95% CI 1.06, 1.65]) and use of three or more antihypertensive drugs (PR 1.09 [95% CI 0.99, 1.20]). Clinically defined low birthweight (<2500 g) yielded stronger associations. Most associations between birthweight and clinical characteristics appeared linear, and a higher birthweight was associated with characteristics mirroring lower birthweight in opposite directions. Results were robust to adjustments for PS representing weighted genetic predisposition for type 2 diabetes and birthweight.

CONCLUSION/INTERPRETATION

Despite younger age at diagnosis, and fewer individuals with obesity and family history of type 2 diabetes, a birthweight <3000 g was associated with more comorbidities, including a higher systolic BP, as well as with greater use of glucose-lowering and antihypertensive medications, in individuals with recently diagnosed type 2 diabetes.

Ethnic differences in kidney function in childhood: the Born in Bradford Cohort Renal Study

Background: Endstage kidney failure rates are higher in South Asians than in White Europeans. Low birth weight is associated with adult chronic kidney disease and is more common in South Asians. Foetal kidney size was smaller in South Asians in the Born in Bradford (BiB) birth cohort. As part of BiB follow up, we aimed to investigate if there were ethnic differences in kidney function and blood pressure in early childhood and whether this was different by foetal kidney size. Methods: Serum creatinine, cystatin C, urea, and urinary albumin to creatinine ratio (ACR), protein to creatinine ratio (PCR) and retinol binding protein (RBP) were analysed in blood and urine samples from those who participated in the BiB follow-up at 7-11 years. Ethnicity was categorised by parental self-report as White European and South Asian. Estimated glomerular filtration rate (eGFR) was calculated using Schwartz, and cystatin C Zappitelli and Filler equations. Linear regression was used to examine the association between ethnicity and eGFR, PCR and blood pressure. Results: 1591 children provided blood (n=1403) or urine (n=625) samples. Mean eGFR was 92 ml/min/1.73m 2 (standard deviation (SD) 9) using Schwartz (n=1156) and 94 (SD 11) using Zappitelli (n=1257). CKD prevalence was rare (1 with eGFR <60 ml/min/1.73m 2, 14 (2.4%) had raised ACR (>2.5 mg/mmol in boys/3.5 mg/mmol in girls). Diastolic blood pressure was higher in South Asian children (difference 2.04 mmHg, 95% CI 0.99 to 3.10) but was not significant in adjusted analysis. There was no evidence of association in adjusted models between ethnicity and any eGFR or urinary measure at this age. Conclusions: There was no evidence of significant ethnic differences in kidney function at pre-pubertal age despite differences in kidney volume at birth. Longitudinal follow-up is required to track ethnic patterns in kidney function and blood pressure as children develop through puberty.

Interventions to address global inequity in diabetes: international progress

Diabetes is a serious chronic disease with high associated burden and disproportionate costs to communities based on socioeconomic, gender, racial, and ethnic status. Addressing the complex challenges of global inequity in diabetes will require intentional efforts to focus on broader social contexts and systems that supersede individual-level interventions. We codify and highlight best practice approaches to achieve equity in diabetes care and outcomes on a global scale. We outline action plans to target diabetes equity on the basis of the recommendations established by The Lancet Commission on Diabetes, organising interventions by their effect on changing the ecosystem, building capacity, or improving the clinical practice environment. We present international examples of how to address diabetes inequity in the real world to show that approaches addressing the individual within a larger social context, in addition to addressing structural inequity, hold the greatest promise for creating sustainable and equitable change that curbs the global diabetes crisis.

Intersectional inequities in the birthweight gap between twin and singleton births: A random effects MAIHDA analysis of 2012-2018 New York City birth data

Birthweight is a widely-used biomarker of infant health, with inequities patterned intersectionally by maternal age, race/ethnicity, nativity/immigration status, and socioeconomic status in the United States. However, studies of birthweight inequities almost exclusively focus on singleton births, neglecting high-risk twin births. We address this gap using a large sample (N = 753,180) of birth records, obtained from the 2012-2018 New York City (NYC) Department of Health and Mental Hygiene, Bureau of Vital Statistics, representing 99% of all births registered in NYC, and a novel random coefficients intersectional MAIHDA (Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy) model. Our results show evidence of intersectional inequities in birthweight outcomes for both twin and singleton births by maternal age, race/ethnicity, education, and nativity status. Twins have considerably lower predicted birthweights than singletons overall (-930 g on average), and this is especially true for babies born to mothers who are younger (11-19 years), older (40+), racial/ethnic minoritized, foreign-born, and have lower education. However, the magnitude of this birthweight 'gap' between twins and singletons varies considerably across social identity strata, ranging between 830.8 g (observed among 40+ year old Black foreign-born mothers with high school degrees) and 1013.7 g (observed among 30-39 year old Hispanic/Latina foreign-born mothers with less than high school degrees). This study underscored the needs of a high-risk population and the need for aggressive social policies to address health inequities and dismantle intersectional systems of marginalization, oppression, and socioeconomic inequality. In addition to our substantive contributions, we add to the growing methods literature on intersectional quantitative analysis by demonstrating how to apply intersectional MAIHDA with random coefficients and random slopes. We conclude with a discussion of the significant potential for this methodological extension in future research on inequities.

Birth size, growth trajectory and later cardio-metabolic risk

There is increasing evidence of a strong association between intrauterine growth and subsequent development of chronic disease in adult life. Birth size and growth trajectory have been demonstrated to have an impact on cardio-metabolic health, both in childhood and adult life. Hence, careful observation of the children's growth pattern, starting from the intrauterine period and the first years of life, should be emphasized to detect the possible onset of cardio-metabolic sequelae. This allows to intervene on them as soon as they are detected, first of all through lifestyle interventions, whose efficacy seems to be higher when they are started early. Recent papers suggest that prematurity may constitute an independent risk factor for the development of cardiovascular disease and metabolic syndrome, regardless of birth weight. The purpose of the present review is to examine and summarize the available knowledge about the dynamic association between intrauterine and postnatal growth and cardio-metabolic risk, from childhood to adulthood.

Beta Cell Dysfunction in Youth- and Adult-Onset Type 2 Diabetes: An Extensive Narrative Review with a Special Focus on the Role of Nutrients

Traditionally a disease of adults, type 2 diabetes (T2D) has been increasingly diagnosed in youth, particularly among adolescents and young adults of minority ethnic groups. Especially, during the recent COVID-19 pandemic, obesity and prediabetes have surged not only in minority ethnic groups but also in the general population, further raising T2D risk. Regarding its pathogenesis, a gradually increasing insulin resistance due to central adiposity combined with a progressively defective β-cell function are the main culprits. Especially in youth-onset T2D, a rapid β-cell activity decline has been observed, leading to higher treatment failure rates, and early complications. In addition, it is well established that both the quantity and quality of food ingested by individuals play a key role in T2D pathogenesis. A chronic imbalance between caloric intake and expenditure together with impaired micronutrient intake can lead to obesity and insulin resistance on one hand, and β-cell failure and defective insulin production on the other. This review summarizes our evolving understanding of the pathophysiological mechanisms involved in defective insulin secretion by the pancreatic islets in youth- and adult-onset T2D and, further, of the role various micronutrients play in these pathomechanisms. This knowledge is essential if we are to curtail the serious long-term complications of T2D both in pediatric and adult populations.

The application of intersectional multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) to examine birthweight inequities in New York City

Exploring the intersection of dimensions of social identity is critical for understanding drivers of health inequities. We used multilevel analysis of individual heterogeneity and discriminatory accuracy (MAIHDA) to examine the intersection of age, race/ethnicity, education, and nativity status on infant birthweight among singleton births in New York City from 2012 to 2018 (N = 725,875). We found evidence of intersectional effects of various systems of oppression on birthweight inequities and identified U.S.-born Black women as having infants of lower-than-expected birthweights. The MAIHDA approach should be used to identify intersectional causes of health inequities and individuals affected most to develop policies and interventions redressing inequities.

Preterm Birth, Small for Gestational Age, and Large for Gestational Age and the Risk of Atrial Fibrillation Up to Middle Age

Importance

Adverse birth outcomes, including preterm birth, small for gestational age (SGA), and large for gestational age (LGA) are associated with increased risks of hypertension, ischemic heart disease, stroke, and heart failure, but knowledge regarding their associations with atrial fibrillation (AF) is limited and inconsistent.

Objective

To investigate whether preterm birth, SGA, or LGA are associated with increased risks of AF later in life.

Design, Setting, and Participants

This multinational cohort study included Danish, Swedish, and Finnish national health registries. Live singleton births in Denmark from 1978 through 2016, in Sweden from 1973 through 2014, and in Finland from 1987 through 2014, who were followed up until December 31, 2016, in Denmark, December 31, 2021, in Sweden, and December 31, 2014, in Finland were included. Data analyses were performed between January 2021 and August 2022.

Exposures

Preterm birth (less than 37 gestational weeks), SGA (less than 10th percentile birth weight for gestational age), and LGA (more than 90th percentile birth weight for gestational age) identified from medical birth registers.

Main Outcomes and Measures

Diagnosis of AF obtained from nationwide inpatient and outpatient registers. The study team ran multivariable Cox proportional hazard models and flexible parametric survival models to estimate hazard ratios (HRs) and 95% CIs for AF according to preterm birth, SGA, and LGA. Sibling analyses were conducted to control for unmeasured familial factors.

Results

The cohort included 8 012 433 study participants (maximum age, 49 years; median age, 21 years; male, 51.3%). In 174.4 million person-years of follow-up, 11 464 participants had a diagnosis of AF (0.14%; median age, 29.3 years). Preterm birth and LGA were associated with increased AF risk in both the full population cohort and in the sibling analyses; the multivariate HRs from the cohort analyses were 1.30 (95% CI, 1.18-1.42) and 1.55 (95% CI, 1.46-1.63), respectively. Preterm birth was more strongly associated with AF in childhood than in adulthood. Children born SGA had an increased risk of AF in the first 18 years of life but not afterwards.

Conclusions and Relevance

Preterm births and LGA births were associated with increased risks of AF up to middle age independently of familial confounding factors. Individuals born SGA had an increased AF risk only during childhood.

Do prenatal factors shape the risk for dementia?: A systematic review of the epidemiological evidence for the prenatal origins of dementia

PURPOSE

Prenatal factors such as maternal stress, infection and nutrition affect fetal brain development and may also influence later risk for dementia. The purpose of this systematic review was to provide an overview of all studies which investigated the association between prenatal factors and later risk for dementia.

METHODS

We systematically searched MEDLINE and Embase for original human studies reporting on associations between prenatal factors and dementia from inception to 23 November 2022. Prenatal factors could be any factor assessed during pregnancy, at birth or postnatally, provided they were indicative of a prenatal exposure. Risk of bias was assessed using the Newcastle Ottawa Scale. We followed PRISMA guidelines for reporting.

RESULTS

A total of 68 studies met eligibility criteria (including millions of individuals), assessing maternal age (N = 30), paternal age (N = 22), birth order (N = 15), season of birth (N = 16), place of birth (N = 13), prenatal influenza pandemic (N = 1) or Chinese famine exposure (N = 1), birth characteristics (N = 3) and prenatal hormone exposure (N = 4). We observed consistent results for birth in a generally less optimal environment (e.g. high infant mortality area) being associated with higher dementia risk. Lower and higher birth weight and prenatal famine exposure were associated with higher dementia risk. The studies on season of birth, digit ratio, prenatal influenza pandemic exposure, parental age and birth order showed inconsistent results and were hampered by relatively high risk of bias.

CONCLUSION

Our findings suggest that some prenatal factors, especially those related to a suboptimal prenatal environment, are associated with an increased dementia risk. As these associations may be confounded by factors such as parental socioeconomic status, more research is needed to examine the potential causal role of the prenatal environment in dementia.

Birth weight, childhood body mass index, and risk of diverticular disease in adulthood

OBJECTIVE

Adult overweight is associated with increased risk of diverticular disease (DD). We investigated associations between birthweight and childhood body mass index (BMI) and DD.

METHODS

Cohort study of 346,586 persons born during 1930-1996 with records in the Copenhagen School Health Records Register. Data included birthweight, and height and weight from ages 7 through 13. We used Cox proportional hazard regression to examine associations between birthweight and BMI z-scores and DD registered in the Danish National Patient Registry. Due to non-proportionality, we followed participants from age 18-49 and from age 50.

RESULTS

During follow-up, 5459 (3.2%) women and 4429 (2.5%) men had DD. For low and high BMI in childhood, we observed a higher risk of DD before age 50. Among women with z-scores <0 at age 13, the hazard ratio (HR) was 1.16 [95% confidence interval (CI): 0.98-1.39] per one-point lower z-score. For z-scores ≥0 at age 13, the HR was 1.30 (95% CI: 1.11-1.51) per one-point higher z-score. Among men with z-scores <0 at age 13, the HR was 1.02 (95% CI: 0.85-1.22). For z-scores ≥0 at age 13, the HR was 1.54 (95% CI: 1.34-1.78). Z-scores ≥0 were not associated with DD after age 50. Among women only, birthweight was inversely associated with DD before age 50 [HR = 0.90 (95% CI: 0.83-0.99) per 500 g higher birthweight].

CONCLUSION

BMI z-scores below and above zero in childhood were associated with higher risk of DD before age 50. In addition, we observed lower risk of DD among women, the higher their birthweight.

Role of foetal kidney size on kidney function in childhood: the born in bradford cohort renal study

BACKGROUND

Foetal and early childhood development contributes to the risk of adult non-communicable diseases such as hypertension and cardiovascular disease. We aimed to investigate whether kidney size at birth is associated with markers of kidney function at 7-11 years.

METHODS

Foetal kidney dimensions were measured using ultrasound scans at 34 weeks gestation and used to derive kidney volume (cm3) in 1802 participants in the Born in Bradford (BiB) birth cohort. Blood and urine samples were taken from those who participated in the BiB follow-up at 7-11 years (n = 630) and analysed for serum creatinine, cystatin C, urea, and urinary albumin to creatinine ratio (ACR), protein to creatinine ratio (PCR) and retinol binding protein (RBP). Estimated glomerular filtration rate (eGFR) was calculated using Schwartz creatinine only and combined with cystatin C, and cystatin C only Zappitelli and Filler equations. Linear regression was used to examine the association between foetal kidney volume and eGFR, ACR, PCR and blood pressure, unadjusted and adjusted for confounders.

RESULTS

Kidney volume was positively associated in adjusted models with eGFR calculated using Schwartz combined (0.64 ml/min diff per unit increase in volume, 95% CI 0.25 to 1.02), Zappitelli (0.79, 95% CI 0.38 to 1.20) and Filler (2.84, 95% CI 1.40 to 4.28). There was an association with the presence of albuminuria but not with its level, or with other urinary markers or with blood pressure.

CONCLUSION

Foetal kidney volume was associated with small increases in eGFR in mid-childhood. Longitudinal follow-up to investigate the relationship between kidney volume and markers of kidney function as children go through puberty is required.

Causal effects of maternal circulating amino acids on offspring birthweight: a Mendelian randomisation study

BACKGROUND

Amino acids are key to protein synthesis, energy metabolism, cell signaling and gene expression; however, the contribution of specific maternal amino acids to fetal growth is unclear.

METHODS

We explored the effect of maternal circulating amino acids on fetal growth, proxied by birthweight, using two-sample Mendelian randomisation (MR) and summary data from a genome-wide association study (GWAS) of serum amino acids levels (sample 1, n = 86,507) and a maternal GWAS of offspring birthweight in UK Biobank and Early Growth Genetics Consortium, adjusting for fetal genotype effects (sample 2, n = 406,063 with maternal and/or fetal genotype effect estimates). A total of 106 independent single nucleotide polymorphisms robustly associated with 19 amino acids (p < 4.9 × 10-10) were used as genetic instrumental variables (IV). Wald ratio and inverse variance weighted methods were used in MR main analysis. A series of sensitivity analyses were performed to explore IV assumption violations.

FINDINGS

Our results provide evidence that maternal circulating glutamine (59 g offspring birthweight increase per standard deviation increase in maternal amino acid level, 95% CI: 7, 110) and serine (27 g, 95% CI: 9, 46) raise, while leucine (-59 g, 95% CI: -106, -11) and phenylalanine (-25 g, 95% CI: -47, -4) lower offspring birthweight. These findings are supported by sensitivity analyses.

INTERPRETATION

Our findings strengthen evidence for key roles of maternal circulating amino acids during pregnancy in healthy fetal growth.

FUNDING

A full list of funding bodies that contributed to this study can be found under Acknowledgments.

Obesity, diabetes mellitus, and pancreatic carcinogenesis: Correlations, prevention, and diagnostic implications

The prevalence of obesity, diabetes mellitus (DM), and pancreatic cancer (PC) has been consistently increasing in the last two decades worldwide. Sharing various influential risk factors in genetics and environmental inducers in pathogenesis, the close correlations of these three diseases have been demonstrated in plenty of clinical studies using multiple parameters among different populations. On the contrary, most measures aimed to manage and treat obesity and DM effectively reduce the risk and prevent PC occurrence, yet certain drugs can inversely promote pancreatic carcinogenesis instead. Most importantly, an elevation of blood glucose with or without a reduction in body weight, along with other potential tools, may provide valuable clues for detecting PC at an early stage in patients with obesity and DM, favoring a timely intervention and prolonging survival. Herein, the epidemiological and etiological correlations among these three diseases and the supporting clinical evidence of their connections are first summarized to favor a better and more thorough understanding of obesity- and DM-related pancreatic carcinogenesis. After comparing the distinct impacts of different weight-lowering and anti-diabetic treatments on the risk of PC, the possible diagnostic implications of hyperglycemia and weight loss in PC screening are also addressed in detail.

Racism, xenophobia, and discrimination: mapping pathways to health outcomes

Despite being globally pervasive, racism, xenophobia, and discrimination are not universally recognised determinants of health. We challenge widespread beliefs related to the inevitability of increased mortality and morbidity associated with particular ethnicities and minoritised groups. In refuting that racial categories have a genetic basis and acknowledging that socioeconomic factors offer incomplete explanations in understanding these health disparities, we examine the pathways by which discrimination based on caste, ethnicity, Indigeneity, migratory status, race, religion, and skin colour affect health. Discrimination based on these categories, although having many unique historical and cultural contexts, operates in the same way, with overlapping pathways and health effects. We synthesise how such discrimination affects health systems, spatial determination, and communities, and how these processes manifest at the individual level, across the life course, and intergenerationally. We explore how individuals respond to and internalise these complex mechanisms psychologically, behaviourally, and physiologically. The evidence shows that racism, xenophobia, and discrimination affect a range of health outcomes across all ages around the world, and remain embedded within the universal challenges we face, from COVID-19 to the climate emergency.

Life Span, Cause of Death and Neoplasia in B6C3F1 Mice Exposed In Utero to Low- and Medium-Dose-Rate Gamma Rays

Previously, we reported that while low-dose-rate (LDR) gamma-ray exposure to 20 mGy/day for the entire gestation period (gestation days 0-18) did not result in any significant effect in B6C3F1 pups up to 10 weeks of age when compared to the non-irradiated controls, exposure to medium-dose-rates (MDR, 200 and 400 mGy/day) resulted in growth retardation and gonadal hypoplasia, in addition to delayed ossification (only at 400 mGy/day). In the present work, we investigated the late effects of continuous in utero exposure to gamma rays at LDRs (0.05, 1.0 and 20 mGy/day) and at an MDR of 400 mGy/day, on life span, causes of death, neoplastic and non-neoplastic disease incidences in B6C3F1 mice. Reproductive parameters such as litter size and weaning rates was not significantly different among the LDR groups, but was significantly decreased in the MDR group, when compared to the non-irradiated controls. Mean life spans were not significantly different among the LDR exposed groups compared to the non-irradiated controls, whereas the life spans of those exposed to the MDR were significantly shorter than the non-irradiated controls. There was no significant difference in tumor spectra between the non-irradiated and LDR nor MDR irradiated groups. In mice exposed to MDR in utero, the over-all incidence rates shifted with increased incidences in the number of neoplasms of liver (both sexes) and endocrine (adrenals, pituitary and ovaries in females) origin with corresponding decreases in the incidence of malignant lymphomas (both sexes) and lung neoplasms (males). Multiple primary neoplasms were significantly increased only in females exposed to MDR. Results show that B6C3F1 mice exposed to gamma-rays in utero at LDRs of 0.05, 1 and 20 mGy/day for the entire gestation period (18 days) does not significantly alter lifespan, cause of death, neoplasm incidence rates and tumor spectra.

Associations between parental type 2 diabetes risk and offspring birthweight and placental weight: a survival analysis using the Walker cohort

AIMS/HYPOTHESIS

Low birthweight (BW) is associated with the development of type 2 diabetes. Genome-wide analyses have identified a strong genetic component to this association, with many BW-associated loci also involved in glucose metabolism. We hypothesised that offspring BW and placental weight (PW) are correlated with parental type 2 diabetes risk, reflecting the inheritance of diabetes risk alleles that also influence fetal growth.

METHODS

The Walker cohort, a collection of birth records from Dundee, Scotland, from the 1950s and the 1960s was used to test this hypothesis by linking BW and PW measurements to parental health outcomes. Using data from SCI-Diabetes and the national death registry, we obtained health records for over 20,000 Walker parents. We performed Fine-Gray survival analyses of parental type 2 diabetes risk with competing risk of death, and Cox regression analyses of risk of death, independently in the maternal and paternal datasets, modelled by offspring BW and PW.

RESULTS

We found significant associations between increased paternal type 2 diabetes risk and reduced offspring BW (subdistribution hazard ratio [SHR] 0.92 [95% CI 0.87, 0.98]) and PW (SHR 0.87 [95% CI 0.81, 0.94]). The association of maternal type 2 diabetes risk with offspring BW or PW was not significant. Lower offspring BW was also associated with increased risk of death in both mothers (HR 0.91 [95% CI 0.89, 0.94]) and fathers (HR 0.95 [95% CI 0.92, 0.98]), and higher offspring PW was associated with increased maternal mortality risk (HR 1.08 [95% CI 1.04, 1.13]) when adjusted for BW.

CONCLUSIONS/INTERPRETATION

We identified associations between offspring BW and reduced paternal type 2 diabetes risk, most likely resulting from the independent effects of common type 2 diabetes susceptibility alleles on fetal growth, as described by the fetal insulin hypothesis. Moreover, we identified novel associations between offspring PW and reduced paternal type 2 diabetes risk, a relationship that might also be caused by the inheritance of diabetes predisposition variants. We found differing associations between offspring BW and PW and parental risk of death. These results provide novel epidemiological support for the use of offspring BW and PW as predictors for future risk of type 2 diabetes and death in mothers and fathers.

Parental pre-pregnancy body mass index and risk of low birth weight in offspring: A prospective cohort study in central China

Background

Low birth weight (LBW) is one of the most common adverse pregnancy outcomes. Previous studies have consistently shown that maternal body mass index (BMI) status before and during pregnancy is associated with LBW. However, previous studies lacked an association between paternal BMI and the conjunction effect of a couple's BMI and LBW in the offspring. Therefore, we established a cohort of pre-pregnancy couples to prospectively assess the relationship between maternal and paternal pre-pregnancy BMI and offspring LBW, very low birth weight (VLBW), and extremely low birth weight (ELBW).

Methods

A prospective cohort study was established in Central China. A total of 34,104 pregnant women with singleton pregnancies at 8-14 gestational weeks and their husbands were finally enrolled and followed to 3 months postpartum. The multivariate logistic regression and restrictive cubic spline model were used to explore the relationship between parental pre-pregnancy BMI and the risk of LBW, VLBW, and ELBW in offspring.

Results

Of the 34,104 participants, maternal pre-pregnancy overweight and obesity were associated with a higher risk of LBW (overweight: OR = 1.720, 95% CI = 1.533 ~ 1.930; obesity: OR = 1.710, 95% CI = 1.360 ~ 2.151), VLBW (overweight: OR = 2.283, 95% CI = 1.839 ~ 2.834; obesity: OR = 4.023, 95% CI = 2.855 ~ 5.670), and ELBW (overweight: OR = 3.292, 95% CI = 2.151 ~ 5.036; obesity: OR = 3.467, 95% CI = 1.481 ~ 8.115), while underweight was associated with a higher risk of LBW (OR = 1.438, 95% CI = 1.294 ~ 1.599) and a lower risk of ELBW (OR = 0.473, 95% CI = 0.236 ~ 0.946). Paternal pre-pregnancy overweight and obesity were associated with a higher risk of LBW (overweight: OR = 1.637, 95% CI = 1.501 ~ 1.784; obesity: OR = 1.454, 95% CI = 1.289 ~ 1.641) and VLBW (overweight: OR = 1.310, 95% CI = 1.097 ~ 1.564; obesity: OR = 1.320, 95% CI = 1.037 ~ 1.681), while underweight was associated with a lower risk of LBW (OR = 0.660, 95% CI = 0.519 ~ 0.839). Parents who were both excessive-weights in pre-pregnancy BMI, as well as overweight mothers and normal-weight fathers before pre-pregnancy, were more likely to have offspring with LBW, VLBW, and ELBW. Dose-response relationship existed between parental pre-pregnancy and LBW, VLBW, and ELBW, except for paternal BMI and ELBW.

Conclusions

Parental pre-pregnancy BMI was associated with the risk of LBW in offspring. Management of weight before pregnancy for couples might help reduce their adverse pregnancy outcomes in future intervention studies.

Low birth weight, nephron number and chronic kidney disease

Chronic kidney diseases have a significant impact on morbidity and mortality worldwide. Low birth weight, fetal growth restriction and prematurity are indicators of fetal growth and development disorders associated with a congenital reduction in nephron number, which predisposes to an increased risk for chronic kidney disease. On an individual basis, a small nephron number at birth is not always enough to determine the onset of chronic kidney disease, but it decreases the ability of the kidneys to resist any insults to renal tissue that may occur later in life, such as exposure to nephrotoxic drugs or episodes of acute kidney injury. The high incidence of low birth weight and preterm birth globally suggests that, at the population level, the impact of alterations in fetal development on the subsequent onset of chronic kidney disease could be significant. The implementation of strategies aimed at reducing the incidence of prematurity, fetal growth restriction, as well as other conditions that lead to low birth weight and a reduced nephron number at birth, provides an opportunity to prevent the development of chronic kidney disease in adulthood. For these purposes the coordinated intervention of several specialists, including obstetricians, gynecologists, neonatologists, nephrologists, and family doctors, is necessary. Such strategies can be particularly useful in resource-poor countries, which are simultaneously burdened by maternal, fetal and child malnutrition; poor health; epidemics caused by communicable diseases; and little access to screening and primary care.

Lower Insulin Sensitivity in Newborns With In Utero HIV and Antiretroviral Exposure Who Are Uninfected in Botswana

BACKGROUND

Few data exist on early-life metabolic perturbations in newborns with perinatal HIV and antiretroviral (ARV) exposure but uninfected (HEU) compared to those perinatally HIV unexposed and uninfected (HUU).

METHODS

We enrolled pregnant persons with HIV (PWH) receiving tenofovir (TDF)/emtricitabine or lamivudine (XTC) plus dolutegravir (DTG) or efavirenz (EFV), and pregnant individuals without HIV, as well as their liveborn infants. Newborns were randomized to receive either zidovudine (AZT) or nevirapine (NVP) postnatal prophylaxis. Preprandial homeostasis model assessment for insulin resistance (HOMA-IR) was assessed at birth and 1 month. Linear mixed models were fit to assess the association between in utero HIV/ARV exposure and average HOMA-IR from birth to 1 month, adjusting for confounders.

RESULTS

Of 450 newborns, 306 were HEU. HOMA-IR was higher in newborns HEU versus HUU after adjusting for confounders (mean difference of 0.068 in log HOMA-IR, P = .037). Among newborns HEU, HOMA-IR was not significantly different between TDF/XTC/DTG versus TDF/XTC/EFV in utero ARV exposure and between AZT versus NVP newborn postnatal prophylaxis arms.

CONCLUSIONS

Newborns HEU versus HUU had lower insulin sensitivity at birth and at 1 month of life, raising potential concern for obesity and other metabolic perturbations later in life for newborns HEU.

CLINICAL TRIALS REGISTRATION

NCT03088410.

Assessing the Content and Quality of Digital Tools for Managing Gestational Weight Gain: Systematic Search and Evaluation

BACKGROUND

Digital health resources have the potential to assist women in optimizing gestational weight gain (GWG) during pregnancy to improve maternal health outcomes.

OBJECTIVE

In this study, we aimed to evaluate the quality and behavior change potential of publicly available digital tools (websites and apps) that facilitate GWG tracking.

METHODS

Digital tools were identified using key search terms across website search engines and app stores and evaluated using the Mobile App Rating Scale, the App Behavior Change Scale, as well as criteria to evaluate the rigor and safety of GWG information.

RESULTS

Overall, 1085 tools were screened for inclusion (162 websites and 923 apps), and 19 were deemed eligible. The mean Mobile App Rating Scale quality score was 3.31 (SD 0.53) out of 5, ranging from 2.26 to 4.39, and the mean App Behavior Change Scale score was 6 (SD 3.4) out of 21, ranging from 19 to 0. Of the 19 items used to evaluate rigor of GWG advice, most tools (n=11, 57.9%) contained ≤3 items.

CONCLUSIONS

This review emphasizes the substantial limitations in current digital resources promoting the monitoring and optimization of GWG. Most tools were of low quality, had minimal behavior change potential, and were potentially unsafe, with minimal linkage to evidence-based information or partnership with health care.

Prevalence, awareness, treatment and control of type 2 diabetes and its determinants among Mongolians in China: a cross-sectional analysis of IMAGINS 2015-2020

OBJECTIVES

This study aims to estimate the prevalence, awareness, treatment and control rates of type 2 diabetes (T2D) and pre-diabetes as well as to identify its associated factors among Mongolians living in the Inner Mongolia Autonomous Region, China.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

This sample included 11 361 Mongolian participants from the Inner Mongolian Healthy Aging Intervention Study, a population-based screening project consisting of 141 255 adults aged above 35 years in Inner Mongolia from 2015 to 31 December 2020.

OUTCOME MEASURES

The prevalence and 95% CIs of T2D and pre-diabetes were calculated. Factors associated with the prevalence, awareness, treatment and control of T2D were explored by a binomial logistic regression.

RESULTS

A total of 17.2% (95% CI 16.5% to 17.9%) of the sample had T2D, of whom 34.0% (95% CI 31.9% to 36.1%) were aware of their diagnosis, 24.7% (95% CI 22.8% to 26.6%) were taking prescribed antidiabetic medications, 6.7% (95% CI 5.6% to 7.8%) had achieved control and 27.5% (95 % CI 26.7% to 28.3%) had pre-diabetes. The prevalence of T2D increased with increasing age, male, lower education level, smoking, obesity and a history of hypertension or dyslipidaemia (all p<0.05).

CONCLUSIONS

T2D is highly prevalent, with suboptimal awareness, treatment and control rates, and an escalating health challenge among the Mongolian population. Broad-based strategies, including diabetes prevention education, better screening and affordable treatment, should be implemented to raise awareness, treatment and control rates of T2D in Inner Mongolia.

ISPAD Clinical Practice Consensus Guidelines 2022: Type 2 diabetes in children and adolescents

Since the 2018 ISPAD guidelines on this topic, follow-up of large cohorts from around the globe have continued informing the current incidence and prevalence of co-morbidities and complications in young adults with youth-onset type 2 diabetes (T2D). This chapter focuses on the risk factors, diagnosis and presentation of youth-onset T2D, the initial and subsequent management of youth-onset T2D, and management of co-morbidities and complications. We include key updates from the observational phase of the multi-center Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) clinical trial, the SEARCH for Diabetes in Youth (SEARCH) study and new data from the Restoring Insulin Secretion (RISE) study, a head-to-head comparison of youth onset vs adult-onset T2D. We also include an expanded section on risk factors associated with T2D, algorithms and tables for treatment, management, and assessment of co-morbidities and complications, and sections on recently approved pharmacologic therapies for the treatment of youth-onset T2D, social determinants of health, and settings of care given COVID-19 pandemic.

Low and insufficient birth weights as important factors of developmental stages of type 2 diabetes: Intergenerational Limache Cohort study

BACKGROUND & AIMS

This study aimed to investigate the association of birth weight with developmental stages of Type 2 Diabetes among Chilean young adults.

METHODS

A probabilistic sample of 1947 individuals (22-28 years) that belong to two birth cohorts (cohort 1: participants born in 1974-1978, cohort 2: participants born in 1988-1992). Multivariable logistic regressions were calculated.

RESULTS

Birth weight was negatively associated with insulin resistance (IR) and dysglycaemia (prediabetes and diabetes) in adulthood (adjusted odds ratio [AOR]: 0.76 (95% confidence interval [CI]: 0.61-0.94), OR: 0.72 (95% CI: 0.60-0.89) for IR and IR plus dysglycaemia, respectively. The AOR for IR plus dysglycaemia for males was 0.72 (95% CI: 0.51-0.99) and for females was 0.77 (95% CI: 0.60-1.01). Birth weight below 3.0 kg (Cohort 2) was associated with 1.40 (95% CI: 1.01-1.95) higher likelihood of IR plus dysglycaemia.

CONCLUSIONS

Our results demonstrate how a population of young adults experienced greater probability of IR, impaired fasting glucose, and diabetes as birth weight decreases. We report a novel finding of effect of suboptimal birth weight on metabolic alterations that belongs to developmental stages of Type 2 Diabetes in young adults born in a period of epidemiological and nutrition transition and grew in post-transition.

A Clinical Update on Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) traditionally refers to abnormal glucose tolerance with onset or first recognition during pregnancy. GDM has long been associated with obstetric and neonatal complications primarily relating to higher infant birthweight and is increasingly recognized as a risk factor for future maternal and offspring cardiometabolic disease. The prevalence of GDM continues to rise internationally due to epidemiological factors including the increase in background rates of obesity in women of reproductive age and rising maternal age and the implementation of the revised International Association of the Diabetes and Pregnancy Study Groups' criteria and diagnostic procedures for GDM. The current lack of international consensus for the diagnosis of GDM reflects its complex historical evolution and pragmatic antenatal resource considerations given GDM is now 1 of the most common complications of pregnancy. Regardless, the contemporary clinical approach to GDM should be informed not only by its short-term complications but also by its longer term prognosis. Recent data demonstrate the effect of early in utero exposure to maternal hyperglycemia, with evidence for fetal overgrowth present prior to the traditional diagnosis of GDM from 24 weeks' gestation, as well as the durable adverse impact of maternal hyperglycemia on child and adolescent metabolism. The major contribution of GDM to the global epidemic of intergenerational cardiometabolic disease highlights the importance of identifying GDM as an early risk factor for type 2 diabetes and cardiovascular disease, broadening the prevailing clinical approach to address longer term maternal and offspring complications following a diagnosis of GDM.

Morbidity and psychomotor development of offspring of women with gestational diabetes: a 5-year follow-up

Background

Gestational diabetes mellitus (GDM) represents a risk factor for both mother and her offspring in a short-term (perinatal morbidity) and long-term horizon (postpartum diabetes or foetal programming). Several studies focused at peri/postnatal outcomes of GDM mother´s offspring, however relatively few (and none in Czech population) were designed as prospective. The aim of the study was to ascertain eventual anthropometric and developmental abnormalities and/or morbidity in offspring of GDM mothers compare to controls in a 5-year follow-up using a parent-reported parameters related to psychomotor development and common paediatric morbidities including a sub-study of offspring of GDM mothers experiencing adverse perinatal outcomes.

Methods

A 5 year follow up study of offspring of GDM mothers (n = 26) vs those with a normal pregnancy (n = 63). An electronic questionnaire was used to obtain the parameters (such as growth, psychomotor development, vaccination, morbidity history etc.) available to parents from the parent-held infant health record. Data on pregnancy and delivery were available from the previous study.

Results

Offspring of GDM mothers had delayed psychomotor development in early childhood, but in 5 years of age they seemed to gradually achieve results of a control group. Children with macrosomia had a higher percentile of weight-for-height and were significantly more frequently ill than those with a normal birth weight. Offspring of obese mothers had worse verbal language skills in early childhood and a higher percentile of weight-for-height.

Conclusion

Maternal gestational diabetes and obesity can be considered an important determinant of postnatal offspring development and health status, which further advocates for broader implementation of preventive strategies.

The Causal Evidence of Birth Weight and Female-Related Traits and Diseases: A Two-Sample Mendelian Randomization Analysis

Objectives: A large meta-analysis indicated a more pronounced association between lower birth weight (BW) and diseases in women but less concern about the causality between BW and female-related phenotypes and diseases.

Methods: Mendelian randomization (MR) analysis was used to estimate the causal relationship between two traits or diseases using summary datasets from genome-wide association studies. Exposure instrumental variables are variants that are strongly associated with traits and are tested using four different statistical methods, including the inverse variance weighting, MR-Egger, weighted median, and weighted mode in MR analysis. Next, sensitivity analysis and horizontal pleiotropy were assessed using leave-one-out and MR-PRESSO packages.

Results: The body mass index (BMI) in adulthood was determined by BW (corrected β = 0.071, p = 3.19E-03). Lower BW could decrease the adult sex hormone-binding globulin (SHBG) level (β = −0.081, p = 2.08E-06), but it resulted in increased levels of bioavailable testosterone (bio-T) (β = 0.105, p = 1.25E-05). A potential inverse effect was observed between BW and menarche (corrected β = −0.048, p = 4.75E-03), and no causal association was confirmed between BW and the risk of endometriosis, leiomyoma, and polycystic ovary syndrome.

Conclusion: Our results suggest that BW may play an important role and demonstrates a significant direct influence on female BMI, SHBG and bio-T levels, and menarche.

Lifestyle intervention during pregnancy in patients with gestational diabetes mellitus and the risk of neonatal hypoglycemia: A systematic review and meta-analysis

Objective

Neonatal hypoglycemia is a severe adverse consequence of infants born to mothers with gestational diabetes mellitus (GDM), which can lead to neonatal mortality, permanent neurological consequences, and epilepsy. This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to explore the effect of lifestyle intervention during pregnancy in women with GDM on the risk of neonatal hypoglycemia.

Methods

PubMed, Web of Science, Cochrane Library, CINAHL, and SPORTDiscus databases were searched by 1st April 2022. Data were pooled as the risk ratio (RR) with 95% CIs of neonatal hypoglycemia. Random-effects, subgroup analyses, meta-regression analysis, and leave-one-out analysis were conducted, involving 18 RCTs.

Results

Prenatal lifestyle intervention could significantly reduce the risk of neonatal hypoglycemia (RR: 0.73, 95% CI: 0.54-0.98, P = 0.037). Subgroup analysis further demonstrated that the reduced risk of neonatal hypoglycemia was observed only when subjects were younger than 30 years, initiated before the third trimester, and with dietary intervention. Meta-regression analysis revealed that the risk of neonatal hypoglycemia post lifestyle intervention was lower in mothers with lower fasting glucose levels at trial entry.

Conclusion

We found that prenatal lifestyle intervention in women with GDM significantly reduced the risk of neonatal hypoglycemia. Only lifestyle intervention before the third trimester of pregnancy, or dietary intervention only could effectively reduce the risk of neonatal hypoglycemia. Future studies are required to explore the best pattern of lifestyle intervention and to determine the proper diagnostic criteria of GDM in the first/second trimester of pregnancy.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#myprospero, PROSPERO, identifier: CRD42021272985.