Victoria Melero-Jiménez

Dr. Victoria Melero-Jiménez


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 January 2023 in Biology
Verified
Journal Article
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FBFrancisco Brenes-Martín
Francisco Brenes-Martín
VMVictoria Melero-Jiménez
Victoria Melero-Jiménez
MLMiguel Ángel López-Guerrero
Miguel Ángel López-Guerrero
MCMaría Mercedes Calero-Ruiz
María Mercedes Calero-Ruiz
LVLuis Vazquez-fonseca
Luis Vazquez-fonseca
FBFernando Bugatto
Fernando Bugatto
Obese women are more likely to experience pregnancy complications. The distribution of fat, and more particularly the rise in visceral fat, is well established to be more closely linked to the onset of cardiovascular disease and metabolic syndrome than obesity itself. We aim to examine the relationship between maternal visceral fat assessment in the first trimester and the appearance of adverse pregnancy outcomes. A prospective cohort study including 416 pregnant women was conducted. During the first trimester scan (11–13 + 6 weeks), all individuals had their visceral fat and subcutaneous thicknesses measured by ultrasonography. Blood samples were obtained, and maternal demographics and clinical information were documented. After delivery, the obstetric outcomes were evaluated. We contrasted two groups: one with healthy pregnancies and the other with adverse pregnancy outcomes (APO), defined as the development of at least one of the following complications: gestational diabetes mellitus, hypertensive disorders of pregnancy, abnormal fetal growth, preterm delivery or preterm premature rupture of membranes. Median maternal age was 33 and 34 years old for the uncomplicated and adverse pregnancy outcomes groups, respectively. We found that women with adverse pregnancy outcomes had higher VFT (median 30 vs. 26.5 mm, p = 0.001) and SFT (median 18.9 vs. 17.1 mm, p = 0.03). However, the visceral/subcutaneous fat ratio was not statistically different between groups. Finally, we performed a subanalysis for metabolic and placental vascular dysfunction complications. After performing a multivariate logistic regression analysis adjusted for maternal age, smoking, and mean arterial pressure, both the VFT (aOR 1.03, p < 0.001) and the ratio of visceral/subcutaneous fat (aOR 1.37, p = 0.04) were significantly associated with the development of adverse pregnancy outcomes; however, the associations of VFT and the VFT-to-SFT ratio were higher for the occurrence of gestational diabetes (aOR 1.07, p < 0.001; aOR 2.09, p = 0.001; respectively) and showed no relationships with placental complications. When conducting a first-trimester ultrasound assessment, sonographers may measure VFT without additional time or cost involved. Identification of pregnant women with increased VFT (>37 mm) may benefit from a close follow-up, especially for the development of gestational diabetes, independent of BMI.

13 January 2026 in Biology
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Journal Article
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JMJessica Abalos martinez
Jessica Abalos martinez
FGFrancisco Visiedo García
Francisco Visiedo García
MCMaria Victoria Cascajo
Maria Victoria Cascajo
Celeste Santos-RosendoCeleste Santos-Rosendo
Celeste Santos-Rosendo
VMVictoria Melero-Jiménez
Victoria Melero-Jiménez
FBFernando Bugatto
Fernando Bugatto
Preeclampsia is a serious pregnancy disorder of unknown etiology. One of its cellular hallmarks is increased mitochondrial dysfunction in placental tissue. Further investigation into this aspect may help elucidate the molecular basis of preeclampsia. A total of 24 pregnant women who delivered by cesarean section participated in the study: n = 13 controls and n = 11 diagnosed with preeclampsia. Maternal blood samples were collected to assess the biochemical profile, and demographic and clinical data were recorded. Placental trophoblast samples were processed to isolate mitochondria and perform molecular biology assays. Women with preeclampsia exhibited the characteristic clinical features of the disease, along with biochemical alterations consistent with an inflammatory process. A significant decrease (73%) in mitochondrial DNA (mtDNA) copy number in trophoblastic tissue and a reduction in citrate synthase (CS) activity (−51%) in cytotrophoblast mitochondria-enriched fractions were observed in preeclampsia, indicating mitochondrial dysfunction accompanied by a loss of functional mitochondrial mass. In addition, we detected a marked decrease in MnSOD levels (−32%), together with an increase in the LC3II/LC3I ratio (47%) in cytotrophoblast mitochondria-enriched fractions, supporting the presence of mitochondrial alterations and suggesting the possible activation of mitophagy specifically in this cell type. Moreover, coenzyme Q10 (CoQ10) levels were elevated by 31% in trophoblastic villi. A pronounced 2.5-fold increase in CoQ10 normalized to CS activity (CoQ10/CS) was detected specifically in cytotrophoblasts from preeclamptic placentas. Importantly, we did not observe these alterations in the syncytiotrophoblast. In conclusion, preeclampsia is associated with mitochondrial dysfunction and increased CoQ10 levels normalized to CS activity, specifically in cytotrophoblast mitochondria, with findings being consistent with a possible involvement of mitophagy in this cell type. These findings suggest that cytotrophoblast mitochondrial metabolism may be more affected in preeclampsia compared with syncytiotrophoblasts, and that CoQ10 accumulation together with the possible activation of mitophagy may represent cellular defense mechanisms. Due to the limitations of the study, it should be considered exploratory and hypothesis-generating, and its results should be regarded as preliminary.

11 July 2025 in Children
Verified
Journal Article
Open access
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Mercedes Horcas-MartínMercedes Horcas-Martín
Mercedes Horcas-Martín
TLTania Luque-Patiño
Tania Luque-Patiño
CPClaudia Usandizaga Prat
Claudia Usandizaga Prat
EFElena Díaz Fernández
Elena Díaz Fernández
VMVictoria Melero-Jiménez
Victoria Melero-Jiménez
FBFernando Bugatto
Fernando Bugatto
Background/Objectives: Pregnancies complicated by idiopathic polyhydramnios are linked to a heightened risk of numerous maternal and perinatal complications. We aim to study the implications of polyhydramnios in term pregnancies complicated with gestational diabetes mellitus (GDM). Methods: A prospective cohort study including 340 GDM cases was conducted. An ultrasound scan was conducted at term between 37 and 40 weeks and amniotic fluid volume (AFV) was assessed by measuring the amniotic fluid index (AFI) and the single deepest pocket (SDP). Maternal demographics and obstetric and perinatal outcomes were evaluated after delivery. We performed comparisons between groups with normal AFV and polyhydramnios (AFI ≥ 24 cm or SDP ≥ 8 cm), and between groups with normal and increased AFV (AFI or SDP ≥ 75th centile). A multivariate logistic regression analysis was performed to study association between AVF measurements and adverse maternal and perinatal outcomes. Results: We found that women with GDM and polyhydramnios at term had a higher risk of maternal (54.3 vs. 27.5%, p < 0.001) and perinatal adverse outcomes (65.7% vs. 46.5%, p < 0.03). The increased AFV group showed a higher risk of fetal overgrowth (LGA: 21.4% vs. 8.2%, p < 0.001 and macrosomia: 19.8% vs. 5.4%, p < 0.001, respectively) and a lesser risk of delivering an SGA fetus (6.3% vs. 13.6%, respectively). Both AFI and SDP showed a significant correlation with newborn weight (r = 0.27; p < 0.001 and r = 0.28; p < 0.001, respectively) and newborn centile (r = 0.26; p < 0.001 and r = 0.26 for both). Subsequent to conducting a multivariate logistic regression analysis adjusted for pregestational BMI, nulliparity, and insulin treatment, both AFI and SDP were significantly associated with perinatal complications, but AFI showed a stronger association with fetal overgrowth (aOR 1.11; p = 0.004 for a LGA fetus and aOR 1.12; p = 0.002 for macrosomia) and with lower risk of delivering an SGA fetus (aOR 0.89; p = 0.009) or IUGR fetus (aOR 0.86; p = 0.03). ROC analysis showed a poor diagnostic performance of both AFI and SDP for identifying macrosomia (AUC 0.68 for AFI, and 0.65 for SDP). Conclusions: Detection of polyhydramnios at term, whether using AFI or SDP, identifies a subgroup of women with gestational diabetes with higher risks of obstetric and perinatal complications. Cases with increased AFV (AFI ≥ 18 cm or SDP ≥ 6.5 cm) are also associated with an increased risk of fetal overgrowth and may require more intensive monitoring for management and optimal delivery timing, with the aim of improve perinatal outcomes.