Search Results (288)

The adrenal medulla and organs of Zuckerkandl consist of chromaffin cells that produce, store, and secrete catecholamines. In humans, the adrenal medulla is known to function throughout postnatal life, while the organs of Zuckerkandl degenerate by 2–3 years of postnatal life. Although the history of investigation of chromaffin cells goes back more than a century, little is known about the reciprocal organogenesis of the adrenal glands and organs of Zuckerkandl during human fetal development. In the current study, we compared these two organs using serial sectioning, routine histological staining, and immunohistochemical reactions in human embryos, prefetuses, and fetuses from 8 to 26 gestational weeks. In our study, we used antibodies for tyrosine hydroxylase, dopamine beta-hydroxylase, and phenylethanolamine N-methyltransferase, which are enzymes of catecholamine synthesis, β-III tubulin, and S100. We found two morphological cell types (large and small) in the developing ganglia, organs of Zuckerkandl, and adrenal medulla, and two migration patterns of large cells and small cells. The immunohistochemical characteristics of these cells were determined. We revealed that the number of small cells increased significantly at the ages from 16 to 21–22 gestational weeks, followed by a decrease at 22.5–26 gestational weeks. The presence of two large cell subpopulations was suggested—those that migrate primarily from organs of the Zuckerkandl region and those that differentiate later from the small cells. We also determined that 12 gestational weeks was the age of the first appearance of phenylethanolamine N-methyltransferase reactivity in developing chromaffin cells, temporally correlating with synaptogenesis events. This is important data in the light of the controversial glucocorticoid theory of phenylethanolamine N-methyltransferase induction in humans. Full article

Background/Objectives: The development of normal fetal cardiac function, a dynamic process that has not yet been precisely documented throughout the literature, is difficult to quantify by classic echocardiography. Our aim was to analyze the function of the fetal myocardium through speckle tracking and establish reference values for global and segmental longitudinal strain for both ventricles in fetuses with a gestational age (GA) between 22 and 39 weeks. Methods: We conducted a prospective study in which 170 fetuses underwent echocardiographic evaluation and those 150 that were eligible for the study underwent offline speckle tracking analysis. Results: A mixed-design ANOVA model with Greenhouse–Geisser correction showed no significant differences in regional strain measurements among GA groups (F [2, 147] = 1.25, p = 0.289) but showed significant differences in regional strain measurements among the right ventricle (RV), left ventricle (LV), and interventricular free wall (Greenhouse–Geisser F [1.3, 195.2] = 45.70, p < 0.001, GG ε = 0.66, original df = 2, 294). The wall-by-segment interaction term of the model was statistically significant for regional strain (Greenhouse–Geisser F [2.7, 394.2] = 27.00, p < 0.001, GG ε = 0.67, original df = 4, 588), while the segment-by-gestational age group term had a tendency toward statistical significance (Greenhouse–Geisser F [3.0, 221.4] = 2.21, p = 0.088, GG ε = 0.75, original df = 4, 294). The results of Welch’s ANOVA model showed no significant difference in right-ventricle peak global longitudinal strain (pGLS) between GA groups (F [2.0, 92.2] = 0.52, p = 0.5972) and global longitudinal strain measurements (F [2.0, 89.6] = 27.00, p = 0.3733). Conclusions: The reference values for longitudinal strain, represented by the pGLS for LV, ranged from −20.79 to −8.05 for fetuses with a GA between 22 and 27 weeks, from −20.14 to −8.99 for fetuses with a GA between 28 and 33 weeks, and from −20.19 to −8.88 for fetuses with a GA between 34 and 39 weeks. For RV pGLS, the reference values were between −18.99 and −6.35, also depending on GA. Reference ranges for the large gestational groups studied can help us to recognize subtle changes in fetal cardiac function. Full article

Background/Objectives: To assess the association between early pregnancy carbohydrate quality, as measured by the Carbohydrate Quality Index (CQI), and the risk of delivering a large-for-gestational-age (LGA) infant in a Mediterranean pregnant cohort of northern Greece. Methods: We analyzed singleton pregnancies from the BORN 2020 prospective cohort in Greece. Dietary intake was assessed via a validated food frequency questionnaire, and CQI was computed from glycemic index, fiber density, whole-to-refined grain ratio, and solid-to-liquid carbohydrate ratio. Multivariable logistic regression was used to estimate the association between CQI (in tertiles) and LGA risk, defined as birthweight >90th percentile. Results: Among the 797 participants, 152 (19.1%) delivered LGA infants, and 117 (14.7%) were diagnosed with GDM. Of those with GDM, 23 (19.7%) delivered LGA infants. In the total population, higher maternal weight (p < 0.001), height (p = 0.006), and pre-pregnancy BMI (p = 0.004) were significantly associated with LGA. A greater proportion of women with LGA had a BMI > 25 (p = 0.007). In the GDM subgroup, maternal height remained significantly higher in those who delivered LGA infants (p = 0.017). In multivariable models, moderate CQI was consistently associated with increased odds of LGA across all models (Model 1: aOR = 1.60 (95% CI: 1.03–2.50), p = 0.037, Model 2: aOR = 1.57 (95% CI: 1.01–2.46), p = 0.046, Model 3: aOR = 1.58 (95% CI: 1.01–2.47), p = 0.044, Model 4 aOR: 1.70; 95% CI: 1.08–2.72; p = 0.023), whereas high CQI was not. In the GDM subgroup, a significant association between high CQI and increased LGA risk was observed in less adjusted models (Model 1 aOR: 6.74; 95% CI: 1.32–56.66; p = 0.039, Model 2 aOR: 6.64; 95% CI: 1.27–57.48; p = 0.044), but this was attenuated and became non-significant in the fully adjusted model (aOR: 3.05; 95% CI: 0.47–30.22; p = 0.28). When examining CQI components individually, no consistent associations were observed. Notably, a higher intake of low-quality carbohydrates (≥50% of energy intake) was significantly associated with increased LGA risk in the total population (aOR: 4.25; 95% CI: 1.53–11.67; p = 0.005). Conclusions: Higher early pregnancy intake of low-quality carbohydrates was associated with an elevated risk of LGA in the general population. However, CQI itself showed a non-linear and inconsistent relationship with LGA, with moderate, but not high, CQI linked to increased risk, particularly in GDM pregnancies, where associations were lost after adjustment. Both carbohydrate quality and quantity evaluations are essential, particularly in high-risk groups, to inform dietary guidance in pregnancy. Full article

Introduction: Fetal ovarian cysts are known to be a common form of fetal abdominal masses in female fetuses, often resulting from hormonal stimulation in utero. Although many resolve spontaneously without sequelae, others can develop into more complex pathologies, such as intracystic hemorrhage or torsion, which can compromise ovarian integrity and long-term reproductive outcomes. Early detection and appropriate follow-up evaluation are therefore crucial for optimal perinatal management. Materials and Methods: We conducted a retrospective study of 12 cases of fetal ovarian cysts diagnosed by routine prenatal ultrasound examinations over a two-year period at our institution. Inclusion criteria were the presence of a cystic adnexal lesion detected in utero, detailed prenatal ultrasound documentation, and a comprehensive postnatal examination. Sonographic features such as cyst size, internal echogenicity, and signs of vascular compromise were recorded. The mother’s clinical variables, including gestational age at diagnosis and relevant medical conditions, were noted. Postnatal follow-up evaluation consisted of ultrasound examinations and, if indicated, pediatric surgical consultation. Results: Of the 12 cases, 9 were characterized by a simple cystic morphology. All spontaneously regressed postnatally and did not require surgical intervention. Three were defined as complex cysts showing septations or echogenic deposits; one of these cysts required immediate surgical exploration for suspected torsion. No cases with a malignant background were identified. All infants showed a favorable course with normal growth and development until follow-up evaluation. Conclusions: This series emphasizes that most fetal ovarian cysts are benign and often resolve without intervention, highlighting the benefit of systematic prenatal imaging. Nevertheless, complex or large cysts require close prenatal and neonatal monitoring to diagnose complications such as torsion. Full article

Background: The Fibroblast Growth Factor (FGF) 19 subfamily plays a key role in the regulation of metabolic and growth processes, and their dysregulation can lead to fetal growth disorders, such as small for gestational age (SGA) and large for gestational age (LGA), as well as to pathogenesis and development of gestational diabetes and gestational hypertension. Methods: We conducted a narrative review using the PRISMA2020 statement. Two electronic databases were searched: PubMed and Web of Science until October 2024. The search terms were as follows: (FGF-21 OR fibroblast growth factor-21 OR FGF-23 OR fibroblast growth factor-23 OR FGF-19 OR fibroblast growth factor-19) AND (human fetus development OR fetal growth OR infancy). We only included original papers that analysed the effect of FGF-19,21,23 on pre- and postnatal development. Results: Only 6 out of 203 studies met the inclusion criteria. There were higher concentrations of FGF-21 among patients with gestational diabetes mellitus (GDM) compared to healthy females, but no differences were found in FGF-21 values in newborn’s umbilical cord blood. Interestingly, higher FGF-21 concentrations were observed in females than males born to patients with GDM. FGF-19 was linked to fetal development by its association with chronic insulin secretion levels during fetal life, particularly in female newborns, but no significant correlation with GDM was found. The evaluation of the role of FGF-23 has shown that its low level could be related to gestational hypertension and fetal growth restriction. Conclusions: In conclusion, all the studies discussed suggest that FGF-19 subfamily factors may play an important role in fetal and neonatal growth and development, particularly in pregnancies complicated by metabolic disorders, such as gestational diabetes or gestational hypertension. Differences in FGF-19 and FGF-21 concentrations based on gender and gestational disorders suggest the need for further research in order to fully understand the effects of these proteins and their potential clinical applications. Full article

Background/Objectives: The aim of this study was to determine the prevalence of functional cardiovascular anomalies detected on fetal echocardiography in third-trimester large-for-gestational-age (LGA) fetuses, who were subsequently born as macrosomic newborns with a birth weight exceeding 4000 g. Methods: A retrospective study was conducted on 1002 fetuses examined during the third trimester at our fetal cardiology center between 2018 and 2024. All fetuses were classified as having “normal heart anatomy” (NHA). Statistical analysis was performed using Microsoft Excel 2024, Statistica 13.1, and EasyMedStat (version 3.37.1). A p-value of <0.05 was considered statistically significant. Results: The 1002 fetuses were divided into two groups. The study group (NHA-LGA) consisted of 167 fetuses born with a weight of >4000 g and the control group (NHA-AGA) was made up of 835 fetuses with a birth weight between 2500 and 4000 g. In the NHA-LGA group, 24 fetuses (14.4%) experienced ductal constriction (DC), while in the NHA-AGA group, it was 11 (1.3%) fetuses (p < 0.00001). Myocardial hypertrophy was observed in 30 fetuses (18.0%) in the NHA-LGA group versus 72 (8.6%) in the NHA-AGA group (p < 0.0003). Additionally, cardiomegaly was noted in 95 fetuses (11.4%) in the NHA-LGA group, compared to 37 (4.4%) in the NHA-AGA group (p < 0.0004). Conclusions: LGA fetuses with normal heart anatomy may present with functional cardiovascular anomalies, including ductal constriction, myocardial hypertrophy, and cardiomegaly. In our cohort, such anomalies were identified in up to 51% of cases. These findings suggest that targeted fetal echocardiographic screening in macrosomic fetuses could be clinically valuable, even in the absence of structural heart defects, and may aid in the early identification of functional cardiac alterations that could impact perinatal management. Full article

Maturity-onset diabetes of the young (MODY)—a monogenic form of diabetes—accounts for approximately 1–2% of all diabetes cases, with GCK-MODY being the second most commonly diagnosed type. Although the inherited nature of the disease implies that the interplay between maternal glycemia and fetal genotype directly influences neonatal outcomes, clinical guidelines for MODY-complicated pregnancies remain underdeveloped. A systematic literature search in the PubMed, Scopus, Web of Science, and Cochrane databases was conducted following the PRISMA guidelines. The study protocol has been logged in the PROSPERO registry with the identification number CRD42024609390. Data, such as MODY type, the gestational age at delivery, mode of delivery, insulin administration, mutational status of the fetus, fetal birthweight (FBW), occurrence of small-/large-for-gestational age fetus, shoulder dystocia, and neonatal hypoglycemia, were extracted and evaluated. Among 19 studies selected for the final analysis, 15 investigated perinatal outcomes in the GCK-MODY variant. Women diagnosed with GCK-MODY treated with insulin delivered approximately 1–2 weeks earlier than those managed with diet alone. FBW was significantly higher in GCK-negative as compared to GCK-positive offspring. Accordingly, fetal macrosomia was notably more common among unaffected neonates. In GCK-affected fetuses, insulin therapy was associated with a significantly lower FBW. Fetal genotype critically modifies perinatal outcomes in GCK-MODY pregnancies. In the absence of fetal genotyping, conservative management should be prioritized to mitigate the risks of fetal growth restriction and iatrogenic prematurity. As data regarding other types of MODY in pregnancy remain sparse, there is an urgent need for more research in this area. Full article

Background/Objective: Small-for-gestational-age (SGA) status constitutes a significant risk factor for adverse neonatal outcomes and predisposes individuals to long-term health complications. Detecting pregnancies at risk early in gestation could significantly improve perinatal outcomes. Recent evidence suggests that ophthalmic artery Doppler assessment in the first trimester may contribute to the prediction of impaired placentation reflected in increased risk for preeclampsia. This study aimed to investigate the association between first-trimester ophthalmic artery Doppler parameters and the subsequent birth of small-for-gestational-age (SGA) neonates. Methods: In this prospective observational analysis, 4054 pregnant women underwent ophthalmic artery Doppler evaluation at 11–13 weeks gestation. Maternal demographics, biophysical and biochemical markers, and ophthalmic artery Doppler measurements of pulsatility index (PI) and peak systolic velocity (PSV) ratio were obtained. Outcomes were classified based on birthweight into the ≤3rd percentile and >3rd percentile and ≤10th percentile and >10th percentile groups. To determine the predictive value of Doppler indices, statistical methods included comparative analyses and the receiver operating characteristic (ROC) curves. Results: The analysis indicated that increased PSV ratio at 11–13 weeks gestation correlated with an increased risk of SGA. The PI was not found to be a significant discriminator between pregnancies complicated by SGA and non-SGA pregnancies. Conclusions: First-trimester ophthalmic artery Doppler assessment offers promise as a non-invasive technique for the early identification of pregnancies at risk for SGA neonates. Further validation through large, multicenter studies is needed to confirm its utility and to standardize its use in clinical protocols. Full article

Background: Two changes to gestational diabetes mellitus (GDM) testing were implemented in the Australian Capital Territory in 2015 and 2017. Aims: We aimed to determine the associations between testing regimes and the prevalence of GDM and large-for-gestational-age (LGA) and small-for-gestational-age (SGA) infants and to compare the prevalence of LGA and SGA infants between women with and without GDM in each testing period. Methods: A total of 23,790 singleton live births with estimated GDM testing and birth dates between June 2012 and December 2019 were stratified into groups: pre-testing changes (June 2012–December 2014, group 1, n = 8069), revised diagnostic criteria (January 2015–May 2017, group 2, n = 8035) and changed pathology centrifugation protocol (June 2017-December 2019, group 3, n = 7686). Women were allocated to groups based on their estimated GDM testing date and stratified by their GDM status. A chi-square test, pairwise z-tests and logistic regression tested the associations. Results: The GDM prevalence significantly increased from 9.5% (group 1) to 19.4% (group 2) to 26.3% (group 3) (all: p < 0.001). The LGA infant prevalence significantly decreased in non-GDM women following revised diagnostic criteria implementation (11.6% vs. 9.7%, p = 0.001). Compared to group 1, women with GDM in groups 2 and 3 had significantly reduced odds of having LGA infants (aOR = 0.73, 95% CI of 0.56–0.95 and p = 0.021 and aOR = 0.75, 95% CI of 0.59–0.97 and p = 0.029, respectively). Compared to group 1, non-GDM women in groups 2 and 3 had significantly reduced odds of having LGA infants (aOR = 0.83, 95% CI of 0.74–0.92 and p < 0.001 and aOR = 0.88, 95% CI of 0.79–0.99 and p = 0.026, respectively). There were no significant associations for group 3 compared to group 2 nor for SGA infants. Conclusions: While significantly increasing the GDM prevalence, implementing the testing changes was associated with a reduced whole-population LGA infant prevalence without a change in the SGA infant prevalence. Full article

Background/Objectives: The objective of this study was to assess the diagnostic accuracy of sonographic estimated fetal weight (EFW) in predicting small (SGA)- or large-for-gestational-age (LGA) birthweight and examine whether the accuracy is associated with maternal body mass index (BMI). Methods: The participants of NICHD Fetal Growth Studies with complete data on maternal BMI (10–13.9 weeks), EFW within 14 days of delivery (18–41.3 weeks), and birthweight were included in this study. Participants were categorized as normal (BMI 18.5–24.9 kg/m²) or overweight/obese (BMI > 24.9 to 44.9 kg/m²). EFW accuracy was evaluated using area under the Receiver Operating Characteristic curves (AUCs) for SGA and LGA classification, and EFW error was analyzed across BMI groups. Results: Among 1289 women, 714 (55.4%) were in the normal BMI group. AUCs for LGA prediction were similar between BMI groups (0.77 ± 0.03 for normal vs. 0.79 ± 0.02 for overweight/obese, p = 0.593). However, for SGA, AUCs were higher in the overweight/obese group (.91 ± 0.01 vs. 0.84 ± 0.02, p = 0.004), indicating improved accuracy. EFW absolute and percent errors were comparable across BMI groups in the full, AGA, and LGA birth cohorts separately, but they trended lower (p = 0.12 and 0.15 for absolute and percent errors, respectively) in the overweight/obese group in the SGA birth cohort. Conclusions: EFW has acceptable accuracy for predicting LGA, unaffected by BMI. However, for SGA, EFW accuracy is significantly higher in the overweight/obese group, suggesting that BMI influences diagnostic performance in SGA but not LGA classification. Full article

Background and Aims: Preterm newborns are particularly susceptible to hypovitaminosis D, potentially impairing bone mineralization. In Thailand, data on its prevalence and standardized supplementation protocols remain limited. This study aimed to compare the efficacy of two vitamin D3 dosages (400 IU/day vs. 800 IU/day) in improving serum vitamin D concentrations and metabolic bone parameters in preterm newborns. Methods: A randomized controlled trial was conducted in preterm newborns born at ≤32 weeks’ gestation or with birth weight ≤1500 g. Preterm newborns were randomized to receive either 400 IU or 800 IU/day of vitamin D3. Serum 25-hydroxyvitamin D (25(OH)D) was measured using electrochemiluminescence immunoassay (ECLIA). Metabolic bone parameters—including calcium, phosphorus, alkaline phosphatase, and albumin—were assessed at baseline and again at six weeks of age. Results: Of the 38 enrolled infants, baseline 25(OH)D levels were comparable between groups (14.8 ± 4.8 ng/mL in the 800 IU/day group vs. 14.7 ± 6.9 ng/mL in the 400 IU/day group). At six weeks, the 800 IU group demonstrated significantly higher 25(OH)D levels (47.3 ± 21.0 ng/mL vs. 32.0 ± 14.2 ng/mL; p = 0.013), with a large effect size (Cohen’s d = 0.85) and the difference-in-differences of +15.7 ng/mL. The prevalence of hypovitaminosis D declined from 89% to 5% in the 800 IU/day group and from 74% to 32% in the 400 IU/day group (p = 0.036). No significant differences in metabolic bone parameters or signs of toxicity were observed. Conclusions: Vitamin D3 supplementation at 800 IU/day significantly improved vitamin D status and reduced hypovitaminosis D in preterm newborns, without observed toxicity. Full article

Background/Objectives: Pre-conception health behaviors may influence the risk of gestational diabetes mellitus (GDM), but evidence on the joint effects of physical activity (PA) and dietary patterns remains limited. This study investigated the associations between pre-conception PA and GDM risk and explored their interaction with adherence to a Mediterranean diet (MD). Methods: This analysis used data from the BORN2020 cohort, which included pregnant women in Greece (2020–2022). Pre-conception PA was assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), expressed as the metabolic equivalent of task (MET)-min/week and categorized into quartiles. Adherence to the MD was assessed via the Trichopoulou score and then grouped into tertiles. Multivariable logistic regression models were computed, accounting for sociodemographic and clinical covariates, including sedentary time and post-lunch nap frequency. Results: In total, 524 women were included and 13.9% (n = 73) were diagnosed with GDM. Women who developed GDM were significantly older (mean age 34.41 vs. 31.98 years, p < 0.0001), were more likely to be >35 years old (46.6% vs. 26.6%, p < 0.001), had higher pre-pregnancy BMI (median 24.6 vs. 22.7 kg/m², p = 0.014), and were more likely to be obese (23.3% vs. 11.8%, p = 0.012). No significant association was observed between total pre-conception PA and GDM risk. Compared to the lowest PA quartile, women in the medium (aOR = 0.80, 95% CI: 0.45–1.40), high (aOR = 1.12, 95% CI: 0.52–2.39), and very high (aOR = 1.10, 95% CI: 0.50–2.38) PA quartiles showed no significant differences in GDM risk. PA, when modeled as a continuous variable, showed no significant trend (aOR = 0.99, 95% CI: 0.99–1.00; p-trend = 0.61). A joint analysis of PA and MD adherence also yielded no significant associations overall. However, in very small BMI-stratified subgroups, a low level of PA combined with very high MD adherence in normal-weight women was associated with increased GDM risk (aOR = 14.06, 95% CI: 1.55–165.54, p = 0.022), while in obese women, very high levels of PA and medium MD adherence showed a potentially protective effect (aOR = 0.006, 95% CI: 8.43 × 10⁻⁶–0.42, p = 0.048). These subgroup findings require cautious interpretation, due to the limited size of the sample set and wide confidence intervals. Conclusions: In this cohort, pre-conception PA, either alone or in combination with MD adherence, was not a reliable predictor of GDM. While our subgroup signals are hypothesis-generating, they do not yet support changes to clinical risk stratification. Future large-scale and interventional studies should investigate combined lifestyle interventions before conception to clarify the potential synergistic effects on GDM prevention. Full article

Background/Objective: The accurate diagnosis of congenital central nervous system abnormalities is critical to pre- and postnatal prognostication and management. When an abnormality is found in the posterior fossa of the fetal brain, parental counseling is challenging because of the wide spectrum of clinical and neurodevelopmental outcomes in patients with Dandy–Walker (DW) spectrum posterior malformations. The objective of this study was to evaluate the utility of biometric measurements obtained from fetal magnetic resonance imaging (MRI) to facilitate the prenatal differentiation of Dandy–Walker (DW) spectrum malformations, including vermian hypoplasia (VH), Blake’s pouch cyst (BPC), and classic Dandy–Walker malformation (DWM). Methods: This retrospective single-center study evaluated 34 maternal–infant dyads referred for fetal MRI evaluation of suspected DW spectrum malformations identified on antenatal ultrasound. Radiologists took posterior fossa measurements, including the vermis anteroposterior (AP) diameter, vermis height (VH), and tegmento–vermian angle (TVA). The posterior fossa, fourth ventricle, and cisterna magna were classified as normal, large, or dilated. The postnatal imaging findings were evaluated for concordance. The acquired values were compared between the groups and with normative data. The genetic testing results are reported when available. Results: A total of 27 DW spectrum fetal MRI cases were identified, including 7 classic DWMs, 14 VHs, and 6 BPCs. The TVA was significantly higher in the DWM group compared with the VH and BPC groups (p < 0.001). All three groups had reduced AP vermis measurements for gestational age compared with normal fetal brains, as well as differences in the means across the groups (p = 0.002). Conclusions: Biometric measurements derived from fetal MRI can effectively facilitate the prenatal differentiation of VH, BPC, and classic DWM when assessing DW spectrum posterior fossa lesions. Standardizing biometric measurements may increase the diagnostic utility of fetal MRI and facilitate improved antenatal counseling and clinical decision-making. Full article

Objectives: This study aimed to test the extra-thyroidal impacts of maternal serum iodine concentrations (SICs) on metabolic factors and subsequent pregnancy outcomes. Methods: Single pregnant women aged 18–49 years were recruited during their first prenatal visits. SICs at first trimester (T1) were tested by ICP-MS. Metabolic factors [body mass index (BMI), fat %, glucose, lipids, uric acid, and blood pressure] were measured, and composite indices [the triglyceride–glucose (TyG) index, TyG-BMI, and the Framingham steatosis index (FSI)] were estimated. Obstetric and birth outcomes were retrieved from the hospital information system, including gestational diabetes (GDM), gestational hypertension (GH), fetal distress, postpartum hemorrhage, premature rupture of membrane, small and large for gestational age (SGA and LGA), preterm birth, and low birth weight. Multivariable linear and logistic regression models were applied to explore the associations between maternal SIC, metabolic factors, and pregnancy outcomes. Results: A total of 1456 mothers were included for analysis. Maternal LgSIC values at T1 were inversely associated with early gestational weight gain (β = −0.113, p < 0.001) and BMI at T1 (β = −0.070, p = 0.006), but they were positively associated with triglycerides (β = 0.142, p < 0.001), the TyG index (β = 0.137, p < 0.001), and uric acid (β = 0.060, p = 0.018). However, upon further adjustment for thyroid hormones, the associations were attenuated. The joint effects of high SIC and metabolic conditions (hyperlipidemia, high FSI, and GH) suggested increased adverse pregnancy outcomes (increased postpartum bleeding, reduced birth length, and reduced delivery weeks). Conclusions: Our prospective data in the iodine replete region indicated that high SICs at T1 were associated with increased risk of metabolic conditions and adverse birth outcomes, with the associations being independent of thyroid hormones. Full article

Background/Objectives: Insulin resistance during pregnancy is a key factor underlying gestational diabetes mellitus (GDM) and other adverse perinatal outcomes (APOs). While traditional markers, such as HOMA-IR, are used to evaluate insulin resistance, they may be inaccessible in resource-limited settings. The triglyceride–glucose (TyG) index has emerged as a practical alternative. This study aimed to assess whether or not a TyG index > 8.6 during the first trimester of pregnancy is associated with an increased risk of APOs, including GDM, preeclampsia, and other maternal and neonatal complications. Methods: A prospective cohort study was conducted involving 333 pregnant women in Mexico City, divided into two groups: Group 1 (TyG index > 8.6, n = 153) and Group 2 (TyG index ≤ 8.6, n = 180). Primary outcomes included gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy, preeclampsia, preterm birth, cesarean section, and large-for-gestational-age (LGA) and small-for-gestational-age (SGA) neonates. Logistic regression models were used to calculate the adjusted relative risk (aRR) and 95% confidence intervals (CIs), adjusting for maternal age, pregestational weight, and body mass index (BMI). Results: Women with a TyG index > 8.6 had a significantly higher pregestational weight and BMI than those with a TyG index ≤ 8.6. Group 1 demonstrated a higher risk of GDM (RR 2.05; 95% CI: 1.23–3.41) and preeclampsia (RR 2.15; 95% CI: 1.10–4.21). After adjusting for maternal age, pregestational weight, and BMI, these associations remained significant: GDM (aRR 1.87; 95% CI: 1.0–2.5) and preeclampsia (aRR 2.18; 95% CI: 1.1–5.0). No significant associations were found between an elevated TyG index and other APOs, including LGA, SGA, preterm birth, or cesarean delivery. Conclusions: A first-trimester TyG index > 8.6 is significantly associated with an increased risk of GDM and preeclampsia, highlighting its potential as a predictive marker for adverse perinatal outcomes. These findings underscore the utility of the TyG index as a practical, cost-effective tool for early risk stratification, particularly in resource-limited settings. Further multi-center research is needed to validate these results and refine population-specific thresholds. Full article