Current Organizations / Institutes

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María Eugenia Mendoza-Flores has a total of 35 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Role of FTO rs9939609 and LEPR rs1137101 Genetic Variants in Gestational Weight Gain and Neonatal Weight Among Pregnant Adolescents

    by Reyna Sámano, Hugo Martínez-Rojano, Ashley Díaz-Medina, Irma Eloísa Monroy-Muñoz, Gabriela Chico-Barba, María Eugenia Mendoza-Flores, Héctor Borboa-Olivares, Verónica Zaga-Clavellina, Ricardo Gamboa, Melissa Daniela Gonzalez-Fernandez, et al.

    Gestational weight gain (GWG) and birth weight (BW) have a multifactorial etiology, which makes identifying the most influential determinants difficult. The association between variants of the FTO and LEPR genes has been explored as contributing factors to obesity in various age groups; however, their role in GWG and BW in adolescent mothers and their offspring is uncertain. To determine whether the presence of polymorphisms rs9939609 (FTO) and rs1137101 (LEPR) is associated with gestational weight gain and newborn weight in a cohort of adolescent mothers. Methods: A prospective cohort study of 305 mother-child dyads was conducted between 2020 and 2024. Genotyping of the single nucleotide variants (SNVs) rs9939609 of the FTO gene and rs1137101 of the LEPR gene was performed using real-time PCR and high-resolution melting analysis (qPCR-HRM), using maternal peripheral blood and umbilical cord blood samples. GWG, BW, energy intake, and other perinatal data were recorded and classified. Genetic data from 305 mother–offspring dyads were analyzed. The median maternal age was 16 years, and 71.4% had a normal pre-pregnancy body mass index (BMI). The most frequent genotypes were TT for FTO rs9939609 and AG for LEPR rs1137101. In both groups, the genotypic distribution significantly deviated from Hardy–Weinberg equilibrium (p < 0.0001). The AA genotype of FTO was associated with a higher probability of excessive gestational weight gain (GWG) after adjustment for pre-pregnancy BMI and dietary and sociodemographic factors. High protein and lipid intake increased the risk of excessive GWG, whereas adequate intake of carbohydrates and legumes showed a protective effect. An initial significant association was identified between the LEPR rs1137101 variant (AA allele) and low birth weight (LBW); however, this association was lost after adjustment for confounding factors. The FTO rs9939609 variant was significantly associated with GWG. On the other hand, the LEPR rs1137101 variant in the offspring showed an association with BW categorized by percentiles (in crude analysis), while the FTO variant showed no relationship with birth weight.

  • Open Access

    Skipping Breakfast and Lunch, as Well as Reducing Milk and Dairy Intake, Is Associated with Depressive Symptoms in Pregnant Adolescents

    by Reyna Sámano, Estefania Aguirre-Minutti, Hugo Martínez-Rojano, Gabriela Chico-Barba, Ricardo Gamboa, Carmen Hernández-Chávez, María Eugenia Mendoza-Flores, Erika González-Medina, Primavera Pérez-Romero

    Background and objective: Depression is the most common mental health problem in women during pregnancy, associated with psychological, social, and medical factors characteristic of this stage. However, a lack of knowledge and limited attention to this condition can aggravate its consequences and restrict access to appropriate treatment. This research seeks to fill a gap in the scientific literature by exploring the association between eating habits and dietary diversity with depressive symptomatology in a group with high psychosocial vulnerability: pregnant adolescents. Material and methods: A cross-sectional analytical study was conducted with a sample of 344 pregnant adolescents attending prenatal care at the National Institute of Perinatology (INPer), a tertiary care center. Non-probabilistic sampling was used for recruitment. Relevant information was collected using a pre-validated structured questionnaire administered via interview. Depressive symptomatology was assessed using the Edinburgh Postnatal Depression Scale (EPDS), with a score of ≥12 considered indicative of a higher risk of depression. Eating habits were evaluated based on meal omission, activities performed during meals, and dietary diversity, comparing them with national recommendations. Food group consumption was assessed using a semi-quantitative Food Frequency Questionnaire (FFQ). Robust variance Poisson regression models were employed to evaluate the independent association between undesirable eating habits, inadequate food group intake, and the presence of depressive symptomatology. Results: A significant association was observed between the presence of depressive symptoms (EPDS ≥ 12) and the omission of main meals. Specifically, skipping breakfast was associated with a higher prevalence of EPDS scores ≥ 12 (aPR = 1.55; 95% CI: 1.10–2.19; p = 0.013). Similarly, adolescents who skipped lunch showed a higher prevalence of depressive symptomatology compared to those who did not (aPR = 2.02; 95% CI: 1.11–3.68; p = 0.022). Regarding food groups, only insufficient intake of milk and dairy products was significantly associated with the presence of depressive symptoms (aPR: 1.78; 95% CI: 1.16–2.73; p = 0.008). Conclusions: This cross-sectional study found a significant association between breakfast skipping, distraction while eating, and inadequate dairy intake with a higher prevalence of depressive symptoms in socially vulnerable pregnant adolescents treated at a tertiary care center. However, due to the study’s design, causality or the direction of the relationship cannot be established (it could be bidirectional), and it cannot be affirmed that modifying the diet will necessarily reduce depression. Furthermore, the results are not generalizable to all pregnant adolescents, and future research (longitudinal or interventional) is needed to better understand these associations before developing specific dietary interventions.


  • Open Access

    Association of Pre- and Gestational Conditions and Barriers to Breastfeeding with Exclusive Breastfeeding Practices

    by Reyna Sámano, Gabriela Chico-Barba, Hugo Martínez-Rojano, María Eugenia Mendoza-Flores, María Hernández-Trejo, Carmen Hernández-Chávez, Andrea Luna-Hidalgo, Estefania Aguirre-Minutti, Ricardo Gamboa, María Eugenia Flores-Quijano, et al.

    Background: Breastfeeding is essential for preventing non-communicable diseases. However, mothers with chronic illnesses tend to breastfeed less, increasing the likelihood of abandoning breastfeeding, especially if they experience gestational complications. Objective: To analyze the association between factors such as prepregnancy maternal characteristics, gestational complications, food security, barriers, and facilitators with the practice of exclusive breastfeeding. Methods: Cross-sectional study with 566 women who had prenatal care and gave birth at the National Institute of Perinatology (Mexico City) between 2021 and 2024. Surveys were administered on breastfeeding practices, food insecurity, barriers, and facilitators of exclusive breastfeeding in mothers. In addition, sociodemographic information, medical history (prepregnancy conditions and complications), gestational weight gain, and neonatal outcomes were recorded. Results: Of the 566 women, only 43.6% practiced exclusive breastfeeding, with a median duration of 4 months. Exclusive breastfeeding was more frequent in young, stay-at-home mothers with lower educational attainment and in those with food insecurity, who also tended to delay the introduction of complementary foods until after six months. Prepregnancy risk conditions (OR 1.56, 95% CI 1.06–2.30) and multiparity (OR 1.64, 95% CI 1.08–2.49) increased the risk of non-exclusive breastfeeding. Conversely, food insecurity (OR 0.40, 95% CI 0.20–0.78) and counseling from healthcare personnel (OR 0.09, 95% CI 0.01–0.51) showed a protective effect. The analysis also showed that paid employment (OR 4.68, 95% CI 1.65–13.21), the perception of low milk production (OR 6.45, 95% CI 2.95–14.10), maternal illness/medication (OR 3.91, 95% CI 1.36–11.28), and fatigue (OR 4.67, 95% CI 1.36–11.28) increased the probability of non-exclusive breastfeeding. Conclusions: In Mexico, the promotion of exclusive breastfeeding faces challenges, especially in mothers who begin pregnancy with significant chronic conditions such as diabetes, hypertension, obesity, advanced maternal age, and hypothyroidism, among others. Healthcare personnel should provide personalized advice to each woman from the prenatal stage on strategies to achieve and maintain exclusive breastfeeding.


  • Open Access

    Differential Effects of Gynecological and Chronological Age on Low Birth Weight and Small for Gestational Age

    by Reyna Sámano, Gabriela Chico-Barba, Estela Godínez-Martínez, Hugo Martínez-Rojano, Ashley Díaz-Medina, María Hernández-Trejo, Pablo César Navarro-Vargas, María Eugenia Flores-Quijano, María Eugenia Mendoza-Flores, Valeria Sujey Luna-Espinosa

    Background: Adolescents with a chronological age of less than 15 years or a gynecological age of less than 2 years may have a higher probability of complications because they are more likely to conceive within 1 to 2 years of menarche and, therefore, are still growing and maturing. This could impair their ability to adapt to the physiological demands of pregnancy. Objective: To evaluate the relationship between chronological age and gynecological age with low birth weight and small for gestational age among adolescent mothers in Mexico City. Methods: A retrospective cohort design of adolescent mother–child dyads was conducted. The study followed 1242 adolescents under 19 years of age and their children, collecting data on physical, socioeconomic, and clinical characteristics, including hemoglobin levels. Low birth weight was assessed using the Intergrowth-21st project standards and categorized as above or below 2500 g. The mothers were grouped by chronological age (p = 0.032)], hemoglobin < 11.5 g/dL [aOR = 2.164, CI 95%; 1.08–605 (p = 0.019)], insufficient gestational weight gain [aOR = 1.858, CI 95%; 1.059–3.260 (p = 0.031)], preterm birth [aOR = 1.689, CI 95%; 1.133–2.519 p = 0.01], and living more than 50 km from the care center [aOR = 2.256, CI 95%; 1.263–4.031 (p = 0.006)]. An early age of menarche [aOR = 0.367, CI 95%; 0.182–0.744 (p = 0.005)] showed a protective effect against small for gestational age. Factors associated with low birth weight included gynecological age < 3 years [aOR = 3.799, CI 95%; 1.458–9.725 (p = 0.006)], maternal age < 15 years [aOR = 5.740, CI 95%; 1.343–26.369 (p = 0.019)], preterm birth [aOR = 54.401, CI 95%; 33.887–87.335, p = 0.001], living more than 50 km from the care center [aOR = 1.930, CI 95%; 1.053–3.536 (p = 0.033)], and early age of menarche [aOR = 0.382, CI 95%; 0.173–0.841 (p = 0.017), which demonstrated a protective effect, respectively. Conclusions: The study concludes that biological immaturity, particularly early gynecological age, significantly contributes to adverse birth outcomes during adolescent pregnancies. Interestingly, early menarche appeared to have a protective effect, whereas chronological age was not a significant predictor of small for gestational age. Chronological age has an even greater impact: women younger than 15 years are 5.7 times more likely to have low birth weight infants. However, chronological age did not increase the likelihood of having an SGA newborn.


  • Open Access

    Low Antenatal Care Number of Consultations Is Associated with Gestational Weight Gain and Birth Weight of Offspring of Teenage Mothers: A Study Based on Colombian and Mexican Cohorts

    by Reyna Sámano, Hugo Martínez-Rojano, Gabriela Chico-Barba, María Eugenia Mendoza-Flores, María Eugenia Flores-Quijano, Ricardo Gamboa, Andrea Luna-Hidalgo, Sandra L Restrepo-Mesa, Jennifer Mier-Cabrera, Guillermina Peña-Camacho

    Background: More than 70% of pregnant adolescents in developing countries experience inappropriate gestational weight gain (GWG). Objective: To determine the association of the number of antenatal care visits (ANC) with GWG, birth weight, and their differences between two countries. Methods: A prospective study was conducted in two cohorts of adolescents, one from Mexico and one from Colombia. The study calculated pregestational body mass index (BMI), obtained GWG and birth weight, and collected socioeconomic characteristics. Birth weight was categorized according to gestational age. A total of 690 mother-child pairs were included, of which 42.6% were Colombian and 57.4% Mexican. Results: The study found no association between socioeconomic characteristics and GWG or birth weight. Colombian adolescents were more likely to experience insufficient GWG (68%), compared with 36% of Mexican adolescents. Colombian adolescents who attended fewer than eight ANC visits were at increased risk of insufficient GWG, whereas Mexican adolescents were at increased risk of excessive GWG. Mexican adolescents who began their pregnancies overweight or obese were at increased risk of excessive GWG. Fewer than eight ANC visits were associated with small for gestational age (SGA) in the Mexican cohort. Conclusions: Inadequate numbers of ANC visits were associated with excessive and insufficient GWG, and SGA. Promoting ANC in adolescent pregnancy is essential to prevent suboptimal GWG and SGA. This study highlights the need for interventions targeting pregnant adolescents from low socioeconomic backgrounds, prioritizing early initiation of prenatal care (first trimester) and a drastic reduction in the high rates of cesarean sections in this group.


  • Open Access

    Serum Folate, Red Blood Cell Folate, and Zinc Serum Levels Are Related with Gestational Weight Gain and Offspring’s Birth-Weight of Adolescent Mothers

    by Reyna Sámano, Hugo Martínez-Rojano, Gabriela Chico-Barba, Ricardo Gamboa, Maricruz Tolentino, Alexa Xiomara Toledo-Barrera, Cristina Ramírez-González, María Eugenia Mendoza-Flores, María Hernández-Trejo, Estela Godínez-Martínez

    Background: Gestational weight gain below or above the Institute of Medicine recommendations has been associated with adverse perinatal and neonatal outcomes. Very few studies have evaluated the association between serum and red blood cell folate concentrations and gestational weight gain in adolescents. Additionally, zinc deficiency during pregnancy has been associated with impaired immunity, prolonged labor, preterm and post-term birth, intrauterine growth restriction, low birth weight, and pregnancy-induced hypertension. Objective: The purpose of our study is to evaluate the association between serum concentrations of zinc, serum folate, and red blood cell folate, with the increase in gestational weight and the weight and length of the newborn in a group of adolescent mothers from Mexico City. Results: In our study, 406 adolescent-neonate dyads participated. The adolescents’ median age was 15.8 years old. The predominant socioeconomic level was middle-low (57.8%), single (57%), 89.9% were engaged in home activities, and 41.3% completed secondary education. Excessive gestational weight gain was observed in 36.7% of cases, while insufficient gestational weight gain was noted in 38.4%. Small for gestational age infants were observed in 20.9% of the sample. Low serum folate (OR 2.1, 95% CI 1.3–3.3), decreased red blood cell folate (OR 1.6, 95% CI 1.0–2.6), and reduced serum zinc concentrations (OR 3.3, 95% CI 2.1–5.2) were associated with insufficient gestational weight gain. Decreased serum zinc levels (OR 1.2, 95% CI 1.2–3.4) were linked to an increased probability of delivering a baby who is small for their gestational age. Conclusions: Low serum folate, red blood cell folate, and serum zinc concentrations were associated with gestational weight gain and having a small gestational age baby. Both excessive and insufficient gestational weight gain, as well as having a small gestational age baby, are frequent among adolescent mothers.


  • Open Access

    Gestational Weight Gain: Is the Role of Genetic Variants a Determinant? A Review

    by Reyna Sámano, Hugo Martínez-Rojano, Gabriela Chico-Barba, Ricardo Gamboa, María Eugenia Mendoza-Flores, Francisco Javier Robles-Alarcón, Itzel Pérez-Martínez, Irma Eloisa Monroy-Muñoz

    Excessive or insufficient gestational weight gain (GWG) leads to diverse adverse maternal and neonatal outcomes. There is evidence that pregestational body mass index (pBMI) plays a role in GWG, but no genetic cause has been identified. In this review, we aim to analyze genotype variants associated with GWG. Results: We identified seven genotype variants that may be involved in GWG regulation that were analyzed in studies carried out in Brazil, Romania, the USA, Turkey, Ukraine, and Canada. Some genetic variants were only associated with GWG in certain races or depending on the pBMI. In women who were obese or overweight before gestation, some genetic variants were associated with GWG. Environmental and genetic factors together showed a greater association with GWG than genetic factors alone; for example, type of diet was observed to have a significant influence. Conclusions: We found little scientific evidence of an association between genotype variants in countries with a high prevalence of women of reproductive age who are overweight and obese, such as in Latin America. GWG may be more dependent on environmental factors than genetic variants. We suggest a deeper study of genetic variants, cytokines, and their possible association with GWG, always with the respective control of potential cofounding factors, such as pBMI, diet, and race.


  • Open Access

    Individual, Family, and Social Factors Associated with Gestational Weight Gain in Adolescents: A Scoping Review

    by Reyna Sámano, Hugo Martínez-Rojano, Luis Ortiz-Hernández, Oralia Nájera-Medina, Gabriela Chico-Barba, Ricardo Gamboa, María Eugenia Mendoza-Flores

    About 56% to 84% of pregnant adolescents have inappropriate (insufficient or excessive) gestational weight gain (GWG); however, the factors associated with GWG in this age group have not been systematically identified. This scoping review aimed to synthesize the available scientific evidence on the association of individual, family, and social factors with inappropriate gestational weight gain in pregnant adolescents. To carry out this review, the MEDLINE, Scopus, Web of Science, and Google Scholar databases were searched for articles from recent years. The evidence was organized according to individual, family, and social factors. The analyzed studies included 1571 adolescents from six retrospective cohorts, 568 from three prospective cohorts, 165 from a case–control study, 395 from a cross-sectional study, and 78,001 from two national representative samples in the USA. At the individual level, in approximately half of the studies, the pre-pregnancy body mass index (pBMI) was positively associated with the GWG recommended by the Institute of Medicine of the USA (IOM). The evidence was insufficient for the other factors (maternal age, number of deliveries, and family support) to determine an association. According to the review, we concluded that pBMI was positively associated with the GWG. More quality studies are needed to assess the association between GWG and individual, family, and social factors.