Ultra-processed food (UPF) consumption during gestation may lead to increased oxidative stress (OS) and could affect pregnancy outcomes. This study aims to evaluate the association of UPF consumption during pregnancy with circulating levels of OS markers. Diet was assessed (average of three assessments) in 119 pregnant women enrolled in the OBESO perinatal cohort (Mexico), obtaining quantitative data and the percentage of energy that UPFs (NOVA) contributed to the total diet. Sociodemographic, clinical (pregestational body-mass index and gestational weight gain) and lifestyle data were collected. Maternal circulating levels of OS markers (malondialdehyde (MDA), protein carbonylation (PC), and total antioxidant capacity (TAC)) were determined at the third trimester of pregnancy. Adjusted linear regression models were performed to analyze the association between UPFs and OS markers. UPFs represented 27.99% of the total energy intake. Women with a lower UPF consumption (<75 percentile°) presented a higher intake of fiber, ω-3, ω-6, and a lower ω-6/3 ratio. Linear regression models showed that UPFs were inversely associated with TAC and MDA. Fiber intake was associated with PC. UPF intake during pregnancy may result in an increase in oxidative stress. When providing nutrition care, limiting or avoiding UPFs may be an intervention strategy that could promote a better antioxidant capacity in the body.

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.

Controversy remains surrounding vitamin D routine supplementation in healthy pregnancy, and the doses are unclear. The aim of this study was to describe maternal vitamin D status throughout pregnancy in a group of Mexican women and evaluate the effect of frequently prescribed doses of vitamin D3 on longitudinal 25-OH-D concentrations, adjusting for obesity, season, and other factors. We conducted a cohort study (Instituto Nacional de Perinatología-INPer) (2017–2020)) of healthy pregnant women without complications. Pregestational overweight/obesity (body mass index ≥ 25), vitamin D3 supplementation (prescribed by physician; 0–250, 250–400, and >400 IU/day), and serum 25-OH-D concentrations (ELISA) were evaluated in each trimester of pregnancy. Vitamin D deficiency or insufficiency was computed (<20 and <30 ng/mL, respectively). We studied 141 adult women; 58.5% had pregestational obesity or overweight. In the first trimester, 45.8% of the women were supplemented with vitamin D3; 51.4% had vitamin D insufficiency and 37.3%, deficiency. In the third trimester, 75.4% of the women were supplemented, and 20% of them still had deficiency. The final general mixed linear model showed that 25-OH-D significantly increased throughout pregnancy (p < 0.001); the highest increase was observed in the third trimester in women with doses >400 IU/day of vitamin D3 (+4 ng/mL, 95% CI: 1.72–8.11 ng/mL). In winter/autumn, 25-OH-D concentrations were also lower (p ≤ 0.05). In this group of pregnant Mexican women, the prevalence of vitamin D deficiency and insufficiency was high. A higher increase in 25-OH-D concentrations during pregnancy was observed when the women were supplemented with >400 IU/day. Common supplementation doses of 250–400 IU/day were insufficient for achieving an adequate maternal vitamin D status.

Background/Objectives: Folate and B12, among other B vitamins, are methyl donors and contribute to multiple DNA methylation processes. Maternal deficiency of these nutrients may be associated with impaired fetal growth, affecting the nutritional status and adiposity of the newborn. This study aimed to describe maternal folate and B12 status throughout pregnancy and evaluate its association with neonatal nutritional status. Methods: We studied 90 healthy pregnant women and their babies from the prospective OBESO cohort (Mexico City). Serum folate and B12 concentrations were measured (ELISA) in the first and third trimesters of pregnancy. Deficiency was considered if serum folate was <4 ng/mL, red blood cell folate (RBC) < 151 ng/mL, active B12 < 40 pmol/L, and total B12 < 203 pg/mL). Maternal supplementation of these nutrients was recorded. Newborn assessment (24–72 h) included weight (BW), length (L), waist circumference (WC), and fat mass percentage (%FM; air-displacement plethysmography). Newborn nutritional status indexes were computed and interpreted (BMI/age and length/age) (term-WHO, preterm-Intergrowth). Mean differences, correlations, and multiple linear and logistic regressions were performed (SPSS v. 29). Results: One-third of women had total vitamin B12 deficiency at the end of pregnancy; no folate deficiency was observed. High doses for both folic acid and B12 supplementation were identified in the third trimester (2057.04 ± 2100.74 μg/d and 7.35 ± 4.56 μg/d). Higher first- and third-trimester maternal active B12 concentrations predicted higher WC and reduced the risk of LBW. Higher first-trimester Thcy levels increased the risk of stunting. Higher third-trimester total B12 and folate concentrations predicted higher WC; the latter was associated with higher FM% at birth. Conclusions: Maternal folate, B12, and Thcy levels influence newborn nutritional status alterations, including adiposity markers. It is vital to guarantee an optimal and balanced maternal B-complex status throughout pregnancy.

To evaluate the association between maternal obesity, gestational diabetes (GDM), and birth size with infant fat-mass (FM) accretion from 1 to 6 months (M). Healthy pregnant women and their term babies from the OBESO cohort were studied (1M-3M, n=122; 1M-6M, n=90). Registered maternal data was: pregestational body-mass-index (preBMI), GDM (2hOGTT), medications, gestational weight gain. Macrosomia (>4000g), large/small for gestational age (LGA/SGA)(weight/age>90° and <90°, respectively-WHO) were recorded at birth. Infant FM (air-displacement plethysmography) was measured (1M, 3M, 6M) and FM accretion computed (ΔkgFM from 1M-3M and 1M-6M). Exclusive breastfeeding (EBF) was assessed. Adjusted-multiple linear regression models were performed. PreBMI was 27.4±5.2kg/m². GDM was present in9%(n=11) of women; 12.3%(n=15) of them received metformin/insulin. One newborn was LGA; 20.7%(n=25) were SGA. From 1M-3M, SGA was a predictor of higher FM accretion (B:0.28, 95%CI:0.14-0.43); GDM was not associated. From 1M-6M, higher FM accretion was observed in SGA newborns (B:0.43, 95%CI:0.19-0.67) and GDM infants (B:0.48, 95%CI:0.06-0.89). In all models (R²≥0.48, p<0.001), infant weight and being female were positively associated, while maternal obesity, metformin/insulin, and EBF were not. GDM appears to program early higher adiposity accretion, independently of excessive fetal growth. SGA was associated with higher FM accretion in early infancy.

Background/Objectives: Vitamin D deficiency has been associated with an increased risk of adverse perinatal outcomes (APOs). This study aimed to examine whether vitamin D deficiency during the first trimester of pregnancy is linked to the development of gestational diabetes mellitus (GDM) in a Mexican population. Methods: A total of 404 pregnant women from the Biochemical and Epigenetic Origin of Overweight and Obesity (OBESO) cohort were included. Maternal vitamin D levels were measured between 11 and 14 weeks of gestation. Vitamin D deficiency was defined as a level below 20.0 ng/mL. The primary goal was to compare APOs between Group 1 (women with vitamin D deficiency) and Group 2 (women without vitamin D deficiency). Adjusted odds ratio (aOR) for APOs—including GDM, preeclampsia, preterm birth, miscarriage, cesarean section, and neonatal size—were calculated, adjusting for pregestational body mass index (BMI) and obesity, with 95% confidence interval (95% CI). Results: Vitamin D deficiency was present in 40.5% of women. Pre-pregnancy BMI and obesity were significantly higher in women with deficiency; other baseline characteristics did not differ between groups. Women with vitamin D deficiency had a higher risk of GDM (aOR 2.04, 95% CI 1.14–3.65, p = 0.01). No association was found between vitamin D deficiency and other APOs. Conclusions: The incidence of vitamin D deficiency in the first trimester was 40.5%. Early pregnancy vitamin D deficiency increases the risk of GDM among Mexican women. These findings highlight the importance of monitoring and supplementing vitamin D during pregnancy to reduce the risk of GDM.