Clinical Research Directory

Placental Imaging Techniques

The goal of this proof-of-concept, case-control, clinical trial is to evaluate the efficacy of using two newer ultrasound technologies, quantitative ultrasound (QUS) and ultrafast power Doppler imaging (uPDI), to evaluate the health of the placenta, visualize blood flow through the placental vasculature by color Doppler imaging in singleton pregnancies with and without fetal growth restriction (FGR). * Our primary objective is to investigate the ability of using these ultrasound technologies to distinguish healthy pregnancies from those affected by FGR, a condition characterized by a fetal weight below the 10th percentile for the gestational age or abdominal circumference of the pregnancy. * Secondary aims include longitudinal evaluation of differences in QUS and uPDI imaging over gestation and changes in these measures with evolution of utero-placental insufficiency including with the development of abnormal umbilical-artery Doppler testing, diagnosis of severe FGR, identification of stillbirth, and detection of preeclampsia or preterm birth. Investigators will compare QUS/uPDI imaging and values in pregnancies determined to be healthy by approved, standard-of-care growth ultrasounds to those diagnosed with FGR. Participants will receive research ultrasounds with the experimental Verasonics Vantage 256 system (Verasonics, Inc, Kirkland, WA) utilizing uPDI/QUS every three weeks following their routine growth ultrasound evaluation until delivery. Demographic, obstetric, and delivery-related information, as well as portions of subjects' past medical history will be utilized by researchers to further contextualize imaging and variables gathered during the research ultrasounds.

AI-Based Ultrasound Prediction of Pregnancy Outcomes in Placental-Related Fetal Growth Restriction (MVM-FGR): A Prospective Cohort Study

The goal of this prospective cohort study is to enroll pregnancies complicated by placental-related fetal growth restriction (FGR) and to develop predictive models for adverse short- and long-term outcomes. This will be achieved by collecting novel intrauterine monitoring indicators along the fetal brain-placenta-heart axis, combined with conventional fetal surveillance parameters, in order to improve risk stratification and guide clinical management, ultimately improving pregnancy outcomes. The study will include pregnant women with singleton pregnancies complicated by isolated early-onset placental insufficiency-related FGR, preferably those with abnormal umbilical artery Doppler findings, who elect to continue the pregnancy. The main question it aims to answer is: • Whether a predictive model integrating novel intrauterine monitoring indicators along the fetal brain-placenta-heart axis with conventional monitoring parameters can accurately predict perinatal and neonatal adverse outcomes in pregnancies complicated by placental-related FGR.

Placental Biology in Health and Disease

Pre-eclampsia (PET) is a condition characterised by high blood pressure and damage to other organs, and is a leading cause of maternal and fetal complications such as fetal growth restriction (FGR). Gestational diabetes mellitus (GDM) involves abnormal blood sugar levels during pregnancy and can have both short and long-term impacts on the health of the mother and child. Both conditions are linked to placental dysfunction but the precise mechanisms behind these links remain unclear. A major focus of this study is on extracellular vesicles (EVs) which are tiny, bubble-like particles released by the placenta into the mother's and baby's bloodstreams. These EVs act as messengers, carrying proteins, lipids and genetic material that can influence how cells function, even in parts of the body far from the placenta. Notably, the number and content of these EVs change in conditions like PET and GDM, suggesting they may play a role in the development of these complications. This single-site, observational, laboratory study aims to investigate how these EVs contribute to maternal health and disease. To enable analysis across different physiological and pathological conditions pregnant participants with healthy pregnancies, pregnancies predisposed to PET and pregnancies complicated by GDM, FGR and PET will be recruited alongside healthy non-pregnant controls. Recruitment will be from the Oxford University Hospitals NHS Foundation Trust and the Nuffield Department of Women's and Reproductive Health, University of Oxford (who fund the research). Demographic and clinical data will be collected as well as blood, urine, breath, placenta, umbilical cord, umbilical cord blood, amniotic fluid and/or uterine vein blood samples. Through examining EV content and function, it is hoped a better understanding of their role in pregnancy complications will be gained, including their potential as non-invasive biomarkers for early detection and targeted treatments, improving outcomes for mothers and babies worldwide.

Amniotic Fluid & the Preterm Gut

Background: Necrotizing enterocolitis (NEC) and sepsis in preterm infants have been linked to intestinal immaturity and preclinical gut microbiota alterations. An important yet understudied contributor in the development of the gastrointestinal tract (GIT) is amniotic fluid (AF). Knowledge is lacking on the critical shifts that may occur in AF in extremely preterm birth. The aim of the current study is to assess the composition of AF using advanced biomedical techniques. Secondary objectives are to assess AF profiles of infants with chorioamnionitis (CAM) and/or fetal growth restriction (FGR), assess key metabolites across gestation, correlate AF profiles with neonatal outcomes, and explore associations with early gut microbiota. Methods: ln this multicenter, prospective, cohort study, AF (\~5 mL) will be collected from obstetric patients delivering their infants extremely preterm (gestational age (GA) 24+0/7-27+6/7 weeks, n=125), either during vaginal delivery or cesarean section (CS). Additionally, AF samples will be collected from a reference group (n=150), including early midtrimester (GA \<23+/7 weeks), very early and moderate to late preterm (GA 28+0/6-36+6/7 weeks), and full-term pregnancies (GA 37+0/7-41+6/7 weeks). Thorough characterization of AF will be conducted, including microbial profiling and metabolomics. Microbiota profiling of neonatal fecal samples will be conducted to assess the association between AF and early neonatal gut colonization patterns. Discussion and expected results: AF profiles associated with CAM and/or FGR in extremely preterm infants are expected to be identified, as well as relevant associations with neonatal health outcomes (including NEC and sepsis) and early neonatal gut colonization patterns. The current study will not only increase the understanding of the GIT development and the pathogenesis of NEC and sepsis but may also aid in the identification of high-risk infants. In the future, these findings may facilitate early targeted microbiota-based interventions to prevent disease progression and ultimately improve clinical outcomes.

Association of Assisted Reproductive Technologies Parameters With the Perinatal Outcome

The goal of this prospective cohort study is to examine how different parameters of assisted reproductive technologies (ART) are associated with the perinatal outcome in individuals with singleton or multiple gestations. The main questions it aims to answer are: Are ART pregnancies associated with a higher risk of: * Small for gestational age neonates? * Fetal growth restriction, either early- or late-onset? * Development of preeclampsia? * Stillbirth (intrauterine fetal death after 22 weeks not due to known anomalies)? * Are certain ART parameters-such as the type of fertilization (e.g., IVF vs. ICSI), embryo stage at transfer, use of fresh vs. frozen embryos, or ovarian stimulation protocols-more strongly associated with adverse outcomes? Are ART pregnancies associated with placental and umbilical cord abnormalities, including: * Placenta previa? * Vasa previa? * Single umbilical artery? * Velamentous or marginal cord insertion? Researchers will compare outcomes between pregnancies conceived through ART and those conceived spontaneously. Participants will: * Be individuals aged 18 or older undergoing routine first-trimester ultrasound between 11 and 14 weeks of gestation * Provide detailed medical, obstetric, and ART-related information * Undergo routine prenatal assessments, including ultrasound evaluations of fetal growth, Doppler studies, and placental characteristics * Have perinatal outcomes such as gestational age at birth, mode of delivery, birthweight, and complications systematically recorded Statistical models will be used to adjust for confounding factors such as maternal age, BMI, parity, and smoking. The aim is to better understand how ART and specific ART parameters may influence maternal and neonatal health and to improve counseling and clinical care for people using fertility treatments.

Cord Blood S100B Protein Concentration in Neonates With Fetal Growth Restriction

S100B protein is a biomarker that increases following central nervous system (CNS) damage. Measuring this protein's levels may allow for the early identification of infants at high risk for developmental abnormalities, such as fetal growth restriction (FGR), even on the first day of life, in a non-invasive manner. Early detection could enable timely interventions and rehabilitation, potentially improving the child's prognosis and long-term outcomes. This study investigates two groups of full-term pregnancies: a study group with prenatally diagnosed late FGR, and a control group with normal fetal growth. Following delivery, cord blood samples from both groups will be analyzed for S100B protein concentrations, pH, base excess (BE), and lactate levels. Additionally, fetal blood flow parameters in the umbilical artery (UA), uterine arteries (UtA), ductus venosus (DV), and middle cerebral artery (MCA) will be monitored via ultrasound within 48 hours before delivery. This study aims to compare S100B protein concentrations in umbilical cord blood between the two groups and to assess correlations with fetal Doppler parameters, pH, BE, and lactate levels in cord blood gas analysis. Ultimately, we seek to determine the effectiveness of S100B protein concentration as a biomarker for diagnosing fetal CNS hypoxia- ischemia in FGR-affected children, compared to those with normal growth.