Pathophysiology from preconception, during pregnancy, and beyond.

Gestational diabetes is the most common medical complication in pregnancy. Historically, gestational diabetes was considered a pregnancy complication involving treatment of rising glycaemia late in the second trimester. However, recent evidence challenges this view. Pre-pregnancy and pregnancy-specific factors influence gestational glycaemia, with open questions regarding roles of non-glycaemic factors in the aetiology and consequences of gestational diabetes. Varying patterns of insulin secretion and resistance in early and late pregnancy underlie a heterogeneity of gestational diabetes in the timing and pathophysiological subtypes with clinical implications: early gestational diabetes and insulin resistant gestational diabetes subtypes are associated with a higher risk of pregnancy complications. Metabolic perturbations of early gestational diabetes can affect early placental development, affecting maternal metabolism and fetal development. Fetal hyperinsulinaemia can affect the development of multiple fetal tissues, with short-term and long-term consequences. Pregnancy complications are prevented by managing glycaemia in early and late pregnancy in some, but not all women with gestational diabetes. A better understanding of the pathophysiology and heterogeneity of gestational diabetes will help to develop novel management approaches with focus on improved prevention of maternal and offspring short-term and long-term complications, from pre-conception, throughout pregnancy, and beyond.

Epidemiology and management of gestational diabetes.

Gestational diabetes is defined as hyperglycaemia first detected during pregnancy at glucose concentrations that are less than those of overt diabetes. Around 14% of pregnancies globally are affected by gestational diabetes; its prevalence varies with differences in risk factors and approaches to screening and diagnosis; and it is increasing in parallel with obesity and type 2 diabetes. Gestational diabetes direct costs are US$1·6 billion in the USA alone, largely due to complications including hypertensive disorders, preterm delivery, and neonatal metabolic and respiratory consequences. Between 30% and 70% of gestational diabetes is diagnosed in early pregnancy (ie, early gestational diabetes defined by hyperglycaemia before 20 weeks of gestation). Early gestational diabetes is associated with worse pregnancy outcomes compared with women diagnosed with late gestational diabetes (hyperglycaemia from 24 weeks to 28 weeks of gestation). Randomised controlled trials show benefits of treating gestational diabetes from 24 weeks to 28 weeks of gestation. The WHO 2013 recommendations for diagnosing gestational diabetes (one-step 75 gm 2-h oral glucose tolerance test at 24-28 weeks of gestation) are largely based on the Hyperglycemia and Adverse Pregnancy Outcomes Study, which confirmed the linear association between pregnancy complications and late-pregnancy maternal glycaemia: a phenomenon that has now also been shown in early pregnancy. Recently, the Treatment of Booking Gestational Diabetes Mellitus (TOBOGM) trial showed benefit in diagnosis and treatment of early gestational diabetes for women with risk factors. Given the diabesity epidemic, evidence for gestational diabetes heterogeneity by timing and subtype, and advances in technology, a life course precision medicine approach is urgently needed, using evidence-based prevention, diagnostic, and treatment strategies.

Metabolomic and genetic architecture of gestational diabetes subtypes.

AIMS/HYPOTHESIS: Physiological gestational diabetes mellitus (GDM) subtypes that may confer different risks for adverse pregnancy outcomes have been defined. The aim of this study was to characterise the metabolome and genetic architecture of GDM subtypes to address the hypothesis that they differ between GDM subtypes. METHODS: This was a cross-sectional study of participants in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study who underwent an OGTT at approximately 28 weeks' gestation. GDM was defined retrospectively using International Association of Diabetes and Pregnancy Study Groups/WHO criteria, and classified as insulin-deficient GDM (insulin secretion <25th percentile with preserved insulin sensitivity) or insulin-resistant GDM (insulin sensitivity <25th percentile with preserved insulin secretion). Metabolomic analyses were performed on fasting and 1 h serum samples in 3463 individuals (576 with GDM). Genome-wide genotype data were obtained for 8067 individuals (1323 with GDM). RESULTS: Regression analyses demonstrated striking differences between the metabolomes for insulin-deficient or insulin-resistant GDM compared to those with normal glucose tolerance. After adjustment for covariates, 33 fasting metabolites, including 22 medium- and long-chain acylcarnitines, were uniquely associated with insulin-deficient GDM; 23 metabolites, including the branched-chain amino acids and their metabolites, were uniquely associated with insulin-resistant GDM; two metabolites (glycerol and 2-hydroxybutyrate) were associated with the same direction of association with both subtypes. Subtype differences were also observed 1 h after a glucose load. In genome-wide association studies, variants within MTNR1B (rs10830963, p=3.43×10-18, OR 1.55) and GCKR (rs1260326, p=5.17×10-13, OR 1.43) were associated with GDM. Variants in GCKR (rs1260326, p=1.36×10-13, OR 1.60) and MTNR1B (rs10830963, p=1.22×10-9, OR 1.49) demonstrated genome-wide significant association with insulin-resistant GDM; there were no significant associations with insulin-deficient GDM. The lead SNP in GCKR, rs1260326, was associated with the levels of eight of the 25 fasting metabolites that were associated with insulin-resistant GDM and ten of 41 1 h metabolites that were associated with insulin-resistant GDM. CONCLUSIONS/INTERPRETATION: This study demonstrates that physiological GDM subtypes differ in their metabolome and genetic architecture. These findings require replication in additional cohorts, but suggest that these differences may contribute to subtype-related adverse pregnancy outcomes.

Prevalence and correlates of diagnosed and probable polycystic ovary syndrome (PCOS) in a cohort of parous women.

OBJECTIVES: To assess correlates of diagnosed and probable polycystic ovary syndrome (PCOS) among parous women. METHODS: This study includes 557 women recruited from multi-specialty clinics in eastern Massachusetts. We categorized women as "diagnosed PCOS" based on medical records and self-reported clinician-diagnoses. Next, we constructed a category of "probable PCOS" for women without a diagnosis but with ≥2 of the following: ovulatory dysfunction (cycle length<21 or ≥35 days), hyperandrogenism (free testosterone>75th percentile), or elevated anti-Müllerian hormone (>75th percentile). We classified the remaining as "no PCOS," and compared characteristics across groups. RESULTS: 9.7% had diagnosed and 9.2% had probable PCOS. The frequency of irregular cycles was similar for diagnosed and probable PCOS. Free testosterone and AMH were higher for probable than diagnosed PCOS. Frequency of irregular cycles and both hormones were higher for the two PCOS groups vs. the no PCOS group. Obesity prevalence for diagnosed PCOS was twice that of probable PCOS (43.9% vs. 19.6%), yet the two groups had similar HbA1c and adiponectin. CONCLUSIONS: Women with probable PCOS are leaner but have comparable glycemic traits to those with a formal diagnosis, highlighting the importance of assessing biochemical profiles among women with irregular cycles, even in the absence of overweight/obesity.

Integrating multiple lines of evidence to assess the effects of maternal BMI on pregnancy and perinatal outcomes.

BACKGROUND: Higher maternal pre-pregnancy body mass index (BMI) is associated with adverse pregnancy and perinatal outcomes. However, whether these associations are causal remains unclear. METHODS: We explored the relation of maternal pre-/early-pregnancy BMI with 20 pregnancy and perinatal outcomes by integrating evidence from three different approaches (i.e. multivariable regression, Mendelian randomisation, and paternal negative control analyses), including data from over 400,000 women. RESULTS: All three analytical approaches supported associations of higher maternal BMI with lower odds of maternal anaemia, delivering a small-for-gestational-age baby and initiating breastfeeding, but higher odds of hypertensive disorders of pregnancy, gestational hypertension, preeclampsia, gestational diabetes, pre-labour membrane rupture, induction of labour, caesarean section, large-for-gestational age, high birthweight, low Apgar score at 1 min, and neonatal intensive care unit admission. For example, higher maternal BMI was associated with higher risk of gestational hypertension in multivariable regression (OR = 1.67; 95% CI = 1.63, 1.70 per standard unit in BMI) and Mendelian randomisation (OR = 1.59; 95% CI = 1.38, 1.83), which was not seen for paternal BMI (OR = 1.01; 95% CI = 0.98, 1.04). Findings did not support a relation between maternal BMI and perinatal depression. For other outcomes, evidence was inconclusive due to inconsistencies across the applied approaches or substantial imprecision in effect estimates from Mendelian randomisation. CONCLUSIONS: Our findings support a causal role for maternal pre-/early-pregnancy BMI on 14 out of 20 adverse pregnancy and perinatal outcomes. Pre-conception interventions to support women maintaining a healthy BMI may reduce the burden of obstetric and neonatal complications. FUNDING: Medical Research Council, British Heart Foundation, European Research Council, National Institutes of Health, National Institute for Health Research, Research Council of Norway, Wellcome Trust.

Associations of Abnormal Maternal Glucose Regulation in Pregnancy with Offspring Adiposity, Insulin Resistance, and Adipokine Markers During Childhood and Adolescence.

OBJECTIVE: To examine the associations of abnormal maternal glucose regulation in pregnancy with offspring adiposity, insulin resistance, adipokine, and inflammatory markers during childhood and adolescence. STUDY DESIGN: Project Viva is a prospective prebirth cohort (n = 2128 live births) initiated from 1999 through 2002 in Eastern Massachusetts, US. During the second trimester of pregnancy, clinicians used 2-step oral glucose challenge testing to screen for gestational diabetes mellitus. In the offspring, we measured anthropometry, insulin resistance, adipokines, lipids, and inflammatory markers in mid-childhood (n = 1107), early adolescence (n = 1027), and mid-adolescence (n = 693). We used multivariable linear regression models and generalized estimating equations adjusted for child age and sex, and for maternal age, race/ethnicity, education, parity, and smoking during pregnancy; we further adjusted for prepregnancy body mass index (BMI). RESULTS: In mid-adolescence (17.1 [0.8] years of age), offspring of mothers with gestational diabetes mellitus (n = 27) had a higher BMI z-score (ß; 95% Cl; 0.41 SD; 0.00, 0.82), sum of skinfolds (8.15 mm; 2.48, 13.82), homeostatic model assessment for insulin resistance (0.81 units; 0.13, 1.50), leptin z-score (0.40 SD; 0.01, 0.78), and leptin/adiponectin ratio z-score (0.51 SD; CI 0.09, 0.93) compared with offspring of mothers with normoglycemia (multivariable-adjusted models). The associations with BMI, homeostatic model assessment for insulin resistance, and adiponectin seemed stronger in mid-adolescence compared with earlier time points. The associations were attenuated toward the null after adjustment for maternal prepregnancy BMI. CONCLUSION: Exposure to gestational diabetes mellitus is associated with higher adiposity, insulin resistance, and altered adipokines in mid-adolescence. Our findings suggest that the peripubertal period could be a key time for the emergence of prenatally programmed metabolic abnormalities.

Validation of Variables for Use in Pediatric Obesity Risk Score Development in Demographically and Racially Diverse US Cohorts.

OBJECTIVE: To evaluate the performance of childhood obesity prediction models in four independent cohorts in the United States, using previously validated variables obtained easily from medical records as measured in different clinical settings. STUDY DESIGN: Data from four prospective cohorts, Latinx, Eating, and Diabetes (LEAD); Stress in Pregnancy Study (SIPS); Project Viva; and Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) were used to test childhood obesity risk models and predict childhood obesity by ages 4 through 6, using five clinical variables (maternal age, maternal pre-pregnancy body mass index, birth weight Z-score, weight-for-age Z-score change, and breastfeeding), derived from a previously validated risk model and as measured in each cohort's clinical setting. Multivariable logistic regression was performed within each cohort, and performance of each model was assessed based on discrimination and predictive accuracy. RESULTS: The risk models performed well across all four cohorts, achieving excellent discrimination. The area under the receiver operator curve (AUROC) was 0.79 for CHAMACOS and Project Viva, 0.83 for SIPS, and 0.86 for LEAD. At a 50th percentile threshold, the sensitivity of the models ranged from 12 to 53%, and specificity was greater than or equal to 90%. The negative predictive values (NPV) were ≥ 80% for all cohorts, and the positive predictive values (PPV) ranged from 62-86%. CONCLUSION: All four risk models performed well in each independent and demographically diverse cohort, demonstrating the utility of these five variables for identifying children at high risk for developing early childhood obesity in the United States.

Metabolomic signatures for blood pressure from early to late adolescence: findings from a U.S. cohort.

INTRODUCTION: Metabolite signatures for blood pressure (BP) may reveal biomarkers, elucidate pathogenesis, and provide prevention targets for high BP. Knowledge regarding metabolites associated with BP in adolescence remains limited. OBJECTIVES: Investigate the associations between metabolites and adolescent BP, both cross-sectionally (in early and late adolescence) and prospectively (from early to late adolescence). METHODS: Participants are from the Project Viva prospective cohort. During the early (median: 12.8 years; N = 556) and late (median: 17.4 years; N = 501) adolescence visits, we conducted untargeted plasma metabolomic profiling and measured systolic (SBP) and diastolic BP (DBP). We used linear regression to identify metabolites cross-sectionally associated with BP at each time point, and to assess prospective associations of changes in metabolite levels from early to late adolescence with late adolescence BP. We used Weighted Gene Correlation Network Analysis and Spearman's partial correlation to identify metabolite clusters associated with BP at each time point. RESULTS: In the linear models, higher androgenic steroid levels were consistently associated with higher SBP and DBP in early and late adolescence. A cluster of 59 metabolites, mainly composed of androgenic steroids, correlated with higher SBP and DBP in early adolescence. A cluster primarily composed of fatty acid lipids was marginally associated with higher SBP in females in late adolescence. Multiple metabolites, including those in the creatine and purine metabolism sub-pathways, were associated with higher SBP and DBP both cross-sectionally and prospectively. CONCLUSION: Our results shed light on the potential metabolic processes and pathophysiology underlying high BP in adolescents.

Plasma metabolomic profile of adiposity and body composition in childhood: The Genetics of Glucose regulation in Gestation and Growth cohort.

OBJECTIVE: This study identified metabolite modules associated with adiposity and body fat distribution in childhood using gold-standard measurements. METHODS: We used cross-sectional data from 329 children at mid-childhood (age 5.3 ± 0.3 years; BMI 15.7 ± 1.5 kg/m2) from the Genetics of Glucose regulation in Gestation and Growth (Gen3G), a prospective pre-birth cohort. We quantified 1038 plasma metabolites and measured body composition using the gold-standard dual-energy x-ray absorptiometry (DXA), in addition to skinfold, waist circumference, and BMI. We applied weighted-correlation network analysis to identify a network of highly correlated metabolite modules. Spearman's partial correlations were applied to determine the associations of adiposity with metabolite modules and individual metabolites with false discovery rate (FDR) correction. RESULTS: We identified a 'green' module of 120 metabolites, primarily comprised of lipids (mostly sphingomyelins and phosphatidylcholine), that showed positive correlations (all FDR p < 0.05) with DXA estimates of total and truncal fat (ρadjusted = 0.11-0.19), skinfold measures (ρadjusted = 0.09-0.26), and BMI and waist circumference (ρadjusted = 0.15 and 0.18, respectively). These correlations were similar when stratified by sex. Within this module, sphingomyelin (d18:2/14:0, d18:1/14:1)*, a sphingomyelin sub-specie that is an important component of cell membranes, showed the strongest associations. CONCLUSIONS: A module of metabolites was associated with adiposity measures in childhood.

History of Infertility and Midlife Cardiovascular Health in Female Individuals.

Importance: Fertility status is a marker for future health, and infertility has been associated with risk for later cancer and diabetes, but associations with midlife cardiovascular health (CVH) in female individuals remain understudied. Objective: To evaluate the association of infertility history with CVH at midlife (approximately age 50 years) among parous individuals. Design, Setting, and Participants: Project Viva is a prospective cohort study of pregnant participants enrolled between 1999 and 2002 who delivered a singleton live birth in the greater Boston, Massachusetts, area. Infertility history was collected at a midlife visit between 2017 and 2021, approximately 18 years after enrollment. Data analysis was performed from January to June 2023. Exposures: The primary exposure was any lifetime history of infertility identified by self-report, medical record, diagnosis, or claims for infertility treatment. Main Outcomes and Measures: The American Heart Association's Life's Essential 8 (LE8) is a construct for ranking CVH that includes scores from 0 to 100 (higher scores denote better health status) in 4 behavioral (diet, physical activity, sleep, and smoking status) and 4 biomedical (body mass index, blood pressure, blood lipids, and glycemia) domains to form an overall assessment of CVH. Associations of a history of infertility (yes or no) with mean LE8 total, behavioral, biomedical, and blood biomarker (lipids and glycemia) scores were examined, adjusting for age at outcome (midlife visit), race and ethnicity, education, household income, age at menarche, and perceived body size at age 10 years. Results: Of 468 included participants (mean [SD] age at the midlife visit, 50.6 [5.3] years) with exposure and outcome data, 160 (34.2%) experienced any infertility. Mean (SD) LE8 scores were 76.3 (12.2) overall, 76.5 (13.4) for the behavioral domain, 76.0 (17.5) for the biomedical domain, and 78.9 (19.2) for the blood biomarkers subdomain. In adjusted models, the estimated overall LE8 score at midlife was 2.94 points lower (95% CI, -5.13 to -0.74 points), the biomedical score was 4.07 points lower (95% CI, -7.33 to -0.78 points), and the blood subdomain score was 5.98 points lower (95% CI, -9.71 to -2.26 points) among those with vs without history of infertility. The point estimate also was lower for the behavioral domain score (ß = -1.81; 95% CI, -4.28 to 0.66), although the result was not statistically significant. Conclusions and Relevance: This cohort study of parous individuals found evidence for an association between a history of infertility and lower overall and biomedical CVH scores. Future study of enhanced cardiovascular preventive strategies among those who experience infertility is warranted.

Associations of prenatal one-carbon metabolism nutrients and metals with epigenetic aging biomarkers at birth and in childhood in a US cohort.

Epigenetic gestational age acceleration (EGAA) at birth and epigenetic age acceleration (EAA) in childhood may be biomarkers of the intrauterine environment. We investigated the extent to which first-trimester folate, B12, 5 essential, and 7 non-essential metals in maternal circulation are associated with EGAA and EAA in early life. Bohlin EGAA and Horvath pan-tissue and skin and blood EAA were calculated using DNA methylation measured in cord blood (N=351) and mid-childhood blood (N=326; median age = 7.7 years) in the Project Viva pre-birth cohort. A one standard deviation increase in individual essential metals (copper, manganese, and zinc) was associated with 0.94-1.2 weeks lower Horvath EAA at birth, and patterns of exposures identified by exploratory factor analysis suggested that a common source of essential metals was associated with Horvath EAA. We also observed evidence nonlinear associations of zinc with Bohlin EGAA, magnesium and lead with Horvath EAA, and cesium with skin and blood EAA at birth. Overall, associations at birth did not persist in mid-childhood; however, arsenic was associated with greater EAA at birth and in childhood. Prenatal metals, including essential metals and arsenic, are associated with epigenetic aging in early life, which might be associated with future health.

Associations of Childhood Adiposity and Cardiometabolic Biomarkers With Adolescent PCOS.

OBJECTIVE: Polycystic Ovary Syndrome (PCOS) is common among females, with significant metabolic and reproductive comorbidities. We describe PCOS development in a pediatric population. METHODS: We assessed cardiometabolic biomarkers and adiposity at the midchildhood (mean 7.9 y), early teen (mean 13.1 y), and midteen (mean 17.8 y) visits among 417 females in the prospective Project Viva cohort. We defined PCOS via self-reported diagnosis or ovulatory dysfunction with hyperandrogenism in midlate adolescence. We used multivariable logistic regression to assess associations of metabolic and adiposity markers at each visit with PCOS. RESULTS: Adolescents with PCOS (n = 56, 13%) versus without had higher mean (SD) BMI z-score and truncal fat mass at the midchildhood (0.66 [0.99] vs 0.30 [1.04]; 3.5 kg [2.6] vs 2.7 [1.5]), early teen (0.88 [1.01] vs 0.25 [1.08]; 9.4 kg [6.7] vs 6.1 [3.4]), and midteen (0.78 [1.03] vs 0.33 [0.97]; 11.6 kg [7.2] vs 9.1 [4.9]) visits as well as lower adiponectin to leptin ratio at the early (0.65 [0.69] vs 1.04 [0.97]) and midteen (0.33 [0.26] vs 0.75 [1.21]) visits. In models adjusted for maternal PCOS, education and child race and ethnicity (social factors), we found higher odds of PCOS per 1-SD increase in truncal fat at midchildhood (odds ratio [OR] 1.42; 95% confidence interval [CI] 1.03-1.95) and early teen visits (OR 1.61; 95% CI 1.14-2.28) and lower odds per 1-SD increase in adiponectin/leptin ratio at the midteen visit (OR 0.14; 95% CI 0.03-0.58). CONCLUSIONS: Childhood excess adiposity and adipose tissue dysfunction may be a first signs of later PCOS risk.

Associations of anti-Müllerian hormone levels among women in their mid-30s with menopausal symptoms ~14 years later.

OBJECTIVE: The aim of this study was to examine associations of anti-Müllerian hormone (AMH) levels in gravid women in their mid-30s with menopausal symptoms ~14 years later and age at natural menopause. METHODS: In this prospective analysis, 474 participants in Project Viva, a longitudinal cohort, were enrolled during pregnancy between 1999 and 2002. AMH levels were determined using plasma samples collected 3 years postpartum. Participants completed the Menopause Rating Scale (MRS) and self-reported age at and reason for menopause at the 17 years postpartum visit (Mid-Life Visit). Primary outcomes were individual MRS item responses and total MRS score. To examine associations between AMH levels and menopausal outcomes, we performed linear and logistic regressions, and survival analyses, adjusting for confounding variables. RESULTS: Mean (SD) AMH level was 2.80 (2.74) ng/mL, measured at 38.2 (3.9) years. At the Mid-Life Visit, mean (SD) age was 52.3 (3.9) years and total MRS score was 8.0 (5.7). During follow-up, 50% had experienced natural menopause, and self-reported mean (SD) age at natural menopause was 50.4 (3.6) years. AMH in the lowest tertile (mean [SD]: 0.47 [0.32] ng/mL) was associated with higher odds of moderate to severe vaginal dryness (adjusted odds ratio: 2.58; 95% CI: 1.16 to 5.73), a lower MRS psychological subscale (adjusted ß: -0.71; 95% CI: -1.35 to -0.07), and earlier attainment of natural menopause (adjusted hazards ratio: 7.1; 95% CI: 4.6 to 11.0) compared with AMH in the highest tertile (mean [SD]: 6.01 [2.37] ng/mL). CONCLUSIONS: Lower AMH in the mid-30s was associated with earlier menopause and increased odds of vaginal dryness but fewer psychological symptoms ~14 years later.

Newborn adiposity is associated with cord blood DNA methylation at IGF1R and KLF7.

OBJECTIVE: This study aimed to identify whether cord blood DNA methylation at specific loci is associated with neonatal adiposity, a key risk factor for childhood obesity. METHODS: An epigenome-wide association study was conducted using the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study as a discovery sample. Linear regression models adjusted for maternal and offspring covariates and cell counts were used to analyze associations between neonatal adiposity as measured by sum of three skinfold thicknesses and cord blood DNA methylation. Assays were performed with Illumina EPIC arrays (791,359 CpG sites after quality control). Replication was performed in an independent cohort, Genetics of Glucose regulation in Gestation and Growth (Gen3G). RESULTS: In 2740 HAPO samples, significant associations were identified at 89 CpG sites after accounting for multiple testing (Bonferroni-adjusted p < 0.05). Replication analyses conducted in 139 Gen3G participants confirmed associations for seven CpG sites. These included IGF1R, which encodes a transmembrane receptor involved in cell growth and survival that binds insulin-like growth factor I and insulin, and KLF7, which encodes a regulator of cell proliferation and inhibitor of adipogenesis; both are key regulators of growth during fetal life. CONCLUSIONS: These findings support epigenetic mechanisms in the developmental origins of neonatal adiposity and as potential biomarkers of metabolic disease risk.

Hair cortisol concentrations are associated with greater adiposity in late adolescence amongst non-Hispanic White individuals.

INTRODUCTION: Hair cortisol concentration (HCC) is a biomarker of long-term stress. Higher HCC is associated with higher adiposity in adults; however, associations are not well characterized in adolescents. OBJECTIVE: To examine cross-sectional associations of HCC with adiposity in late adolescence. METHODS: Amongst 336 non-Hispanic White participants (48.5% female, mean 17.7 years) in Project Viva, we used multivariable linear regression models, overall and sex-stratified, to estimate associations of HCC with body mass index (BMI), bioelectric impedance (BIA) percent body fat, waist circumference (WC) and dual X-ray absorptiometry-measured percent and total fat or trunk fat mass. We adjusted models for age and known predictors of adiposity. RESULTS: Median (interquartile range) HCC was 2.1 pm/mg (1.0-4.5) and mean (SD) BMI was 23.1 kg/m2 (3.9), BIA %body fat 20.2% (9.9) and WC 80.6 cm (10.9). In adjusted models, higher HCC (per doubling) was associated with higher BMI (ß = 0.19 kg/m2; 95%CI 0.00, 0.37) and BIA percent body fat (ß = 0.41%; 95%CI 0.04, 0.77). We observed no evidence of effect modification by sex. CONCLUSIONS: Higher HCC was associated with greater adiposity in late adolescence. Further research is needed to disentangle the relationship between HCC and adolescent adiposity, including the temporal direction of the relationship and sex-specific associations.

Maternal obesity and offspring neurodevelopment are associated with hypoxic gene expression in term human placenta.

One third of women in the United States are affected by obesity during pregnancy. Maternal obesity (MO) is associated with an increased risk of neurodevelopmental and metabolic disorders in the offspring. The placenta, located at the maternal-fetal interface, is a key organ determining fetal development and likely contributes to programming of long-term offspring health. We profiled the term placental transcriptome in humans (pre-pregnancy BMI 35+ [MO condition] or 18.5-25 [lean condition]) using single-nucleus RNA-seq to compare expression profiles in MO versus lean conditions, and to reveal potential mechanisms underlying offspring disease risk. We recovered 62,864 nuclei of high quality from 10 samples each from the maternal-facing and fetal-facing sides of the placenta. On both sides in several cell types, MO was associated with upregulation of hypoxia response genes. On the maternal-facing side only, hypoxia gene expression was associated with offspring neurodevelopmental measures, in Gen3G, an independent pregnancy cohort with bulk placental tissue RNA-seq. We leveraged Gen3G to determine genes that correlated with impaired neurodevelopment and found these genes to be most highly expressed in extravillous trophoblasts (EVTs). EVTs further showed the strongest correlation between neurodevelopment impairment gene scores (NDIGSs) and the hypoxia gene score. We reanalyzed gene expression of cultured EVTs, and found increased NDIGSs associated with exposure to hypoxia. Among EVTs, accounting for the hypoxia gene score attenuated 44% of the association between BMI and NDIGSs. These data suggest that hypoxia in EVTs may be a key process in the neurodevelopmental programming of fetal exposure to MO.

First trimester plasma PER- AND Polyfluoroalkyl Substances (PFAS) and blood pressure trajectories across the second and third trimesters of pregnancy

BACKGROUND: Evidence suggests that exposure to per- and polyfluoroalkyl substances (PFAS) increases risk of high blood pressure (BP) during pregnancy. Prior studies did not examine associations with BP trajectory parameters (i.e., overall magnitude and velocity) during pregnancy, which is linked to adverse pregnancy outcomes. OBJECTIVES: To estimate associations of multiple plasma PFAS in early pregnancy with BP trajectory parameters across the second and third trimesters. To assess potential effect modification by maternal age and parity. METHODS: In 1297 individuals, we quantified six PFAS in plasma collected during early pregnancy (median gestational age: 9.4 weeks). We abstracted from medical records systolic BP (SBP) and diastolic BP (DBP) measurements, recorded from 12 weeks gestation until delivery. BP trajectory parameters were estimated via Super Imposition by Translation and Rotation modeling. Subsequently, Bayesian Kernel Machine Regression (BKMR) was employed to estimate individual and joint associations of PFAS concentrations with trajectory parameters - adjusting for maternal age, race/ethnicity, pre-pregnancy body mass index, income, parity, smoking status, and seafood intake. We evaluated effect modification by age at enrollment and parity. RESULTS: We collected a median of 13 BP measurements per participant. In BKMR, higher concentration of perfluorooctane sulfonate (PFOS) was independently associated with higher magnitude of overall SBP and DBP trajectories (i.e., upward shift of trajectories) and faster SBP trajectory velocity, holding all other PFAS at their medians. In stratified BKMR analyses, participants with ≥ 1 live birth had more pronounced positive associations between PFOS and SBP velocity, DBP magnitude, and DBP velocity - compared to nulliparous participants. We did not observe significant associations between concentrations of the overall PFAS mixture and either magnitude or velocity of the BP trajectories. CONCLUSION: Early pregnancy plasma PFOS concentrations were associated with altered BP trajectory in pregnancy, which may impact future cardiovascular health of the mother.

Placental IGFBP1 levels during early pregnancy and the risk of insulin resistance and gestational diabetes.

Reduced insulin sensitivity (insulin resistance) is a hallmark of normal physiology in late pregnancy and also underlies gestational diabetes mellitus (GDM). We conducted transcriptomic profiling of 434 human placentas and identified a positive association between insulin-like growth factor binding protein 1 gene (IGFBP1) expression in the placenta and insulin sensitivity at ~26 weeks gestation. Circulating IGFBP1 protein levels rose over the course of pregnancy and declined postpartum, which, together with high gene expression levels in our placenta samples, suggests a placental or decidual source. Higher circulating IGFBP1 levels were associated with greater insulin sensitivity (lesser insulin resistance) at ~26 weeks gestation in the same cohort and in two additional pregnancy cohorts. In addition, low circulating IGFBP1 levels in early pregnancy predicted subsequent GDM diagnosis in two cohorts of pregnant women. These results implicate IGFBP1 in the glycemic physiology of pregnancy and suggest a role for placental IGFBP1 deficiency in GDM pathogenesis.

First-Trimester Plasmatic microRNAs Are Associated with Fasting Glucose Levels in Late Second Trimester of Pregnancy.

Maternal blood glucose regulation adaptation to pregnancy aims to support fetal growth but may also lead to the development of gestational diabetes mellitus, the most common pregnancy complication. MiRNAs are small RNA molecules secreted and stable in the blood, where they could have paracrine hormone-like functions (ribo-hormone) and regulate metabolic processes including fetal growth and glucose metabolism. The objective of this study was to identify plasmatic microRNA (miRNAs) measured during the first trimester of pregnancy that were associated with glucose levels during a 75 g oral glucose tolerance test (OGTT) at ~26 weeks of pregnancy. miRNAs were quantified using next-generation sequencing in 444 pregnant women and replicated in an independent cohort of 106 pregnant women. MiRNAs associated with glucose levels were identified with the DESeq2 package. We identified 24 miRNAs associated with fasting glycemia, of which 18 were common to both cohorts (q-value < 0.1). However, no association was found between miRNAs and 1 h or 2 h post OGTT glycemia. To conclude, we identified 18 miRNAs early in pregnancy that were associated with fasting blood glucose measured 3 months later. Our findings offer new insights into the mechanisms involved in fasting glucose homeostasis regulation in pregnancy, which is critical to understanding how gestational diabetes develops.

First trimester prenatal metal mixtures, vitamins, and hypertensive disorders of pregnancy in the project viva cohort.

BACKGROUND: Hypertensive disorders of pregnancy (HDP) such as preeclampsia and gestational hypertension are major contributors to maternal and child morbidity and mortality. Previous studies have reported associations with selected metals and vitamins but are limited in sample size and non-prospective study designs. We evaluated prospective associations of metal mixtures with HDP and tested interactions by vitamins. STUDY DESIGN: We measured first trimester (median = 10.1 weeks) concentrations of essential (copper, magnesium, manganese, selenium, zinc) and nonessential (arsenic, barium, cadmium, cesium, mercury, lead) metals in red blood cells (n = 1,386) and vitamins (B12 and folate) in plasma (n = 924) in Project Viva, a pre-birth US cohort. We collected diagnosis of HDP by reviewing medical records. We used multinomial logistic regression and Bayesian Kernel Machine Regression to estimate individual and joint associations of metals with HDP and interactions by vitamins, after adjusting for key covariates. RESULTS: The majority of participants were non-Hispanic white (72.5 %), never smokers (68.5 %) with a mean (SD) age of 32.3 (4.6) years. Fifty-two (3.8 %) developed preeclampsia and 94 (6.8 %) gestational hypertension. A doubling in first trimester erythrocyte copper was associated with 78 % lower odds of preeclampsia (OR=0.22, 95 % confidence interval: 0.08, 0.60). We also observed significant associations between higher erythrocyte total arsenic and lower odds of preeclampsia (OR=0.80, 95 % CI: 0.66, 0.97) and higher vitamin B12 and increased odds of gestational hypertension (OR=1.79, 95 % CI: 1.09, 2.96), but associations were attenuated after adjustment for dietary factors. Lower levels of the overall metal mixture and essential metal mixture were associated with higher odds of preeclampsia. We found no evidence of interactions by prenatal vitamins or between metals. CONCLUSION: Lower levels of a first-trimester essential metal mixture were associated with an increased risk of preeclampsia, primarily driven by copper. No associations were observed between other metals and HDP after adjustment for confounders and diet.