Placenta

Cadmium is a toxic heavy metal naturally present in the environment, whose human exposure has increased over recent decades due to diffuse anthropogenic contamination, particularly related to industrial activities and the use of mineral phosphate fertilizers in agriculture. Cadmium is characterized by its bioaccumulative properties and well-established toxicity, including renal and bone damage and carcinogenic effects. In pregnant women, several animal and human cohort studies have shown that cadmium can cross the placental barrier and accumulate in placental tissue. Placental cadmium exposure has been associated with impaired placental function and adverse perinatal outcomes, including fetal growth restriction and increased neonatal morbidity. In the general population without occupational exposure, diet represents the main source of cadmium exposure, apart from tobacco smoking. Fetal growth, commonly assessed through birth weight adjusted for gestational age, is a major determinant of neonatal and long-term health outcomes. This monocentric prospective pilot study aims to assess fetal exposure to cadmium during pregnancy using placental cadmium concentration as a biomarker. Placental samples will be collected at delivery from women giving birth at Amiens University Hospital, and cadmium levels will be measured using inductively coupled plasma mass spectrometry. The association between placental cadmium concentration and fetal growth will be explored. Fetal growth will be evaluated using birth weight adjusted for gestational age, expressed as a standardized z-score. Maternal urinary and blood cadmium concentrations will also be measured to characterize maternal exposure and explore correlations between biological matrices. Placental efficiency, defined as the fetal-to-placental weight ratio, will be assessed as an indicator of placental function. The results of this pilot study will provide preliminary data to inform future larger-scale epidemiological and mechanistic studies on prenatal cadmium exposure and pregnancy outcomes.

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, voice, 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.

This prospective study aims to collate a comprehensive database of all main monochorionic twin groups to enable comparisons to be made within each twin group and additionally between each group with regards to several placental characteristics, whilst understanding their impact on several fetal outcomes. This study aims to provide new insights in to how the placental architecture influences pregnancy care within the UK pregnancy cohort. Results of this study may impact how clinicians conduct antenatal surveillance for these anatomical placental factors. Patients of both uncomplicated and complication monochorionic twin groups will be consented at a single site and recruited during the antenatal period. Following delivery the placenta will then be analysed macroscopically and assessed for several anatomical features. This will be compared with the antenatal complications and perinatal outcomes for the respective twin.