La technique de clonage par transfert nucléaire de cellules somatiques (SCNT) présente une page importante dans les annales scientifiques, mais son application pratique demeure incertaine dû à son faible taux de succès. Les anomalies placentaires et de développement fœtal se traduisent par des pertes importantes de gestation et des mortalités néonatales. Dans un premier temps, la présente étude a caractérisé les changements morphologiques des membranes fœtales durant la gestation clonée en les comparant à des gestations contrôles obtenues à partir de l’insémination artificielle. Les différentes anomalies morphologiques des placentomes telles que l’œdème chorioallantoique, la présence de zones hyperéchoiques et irrégulières dans la membrane amniotique et la présence de cellules inflammatoires dégénérées compromettent le développement fœtal normal de la gestation clonée. L’examen ultrasonographique représente une technique diagnostique importante pour faire le suivi d’une gestation et de caractériser les changements placentaires dans le cadre d’évaluation globale du bien-être fœtal. Le profil hormonal de trois stéroïdes (progestérone (P4), estrone sulfate (E1S), et œstradiol (E2)) et de la protéine B spécifique de gestation (PSPB) dans le sérum des vaches porteuses de clones SCNT a été déterminé et associé aux anomalies de gestations clonées. Une diminution de la P4 sérique au jour 80, une élévation du niveau de la concentration de la PSPB au jour 150, et une augmentation de la concentration d’E2 sérique durant le deuxième et troisième tiers de la gestation clonée coïncident avec les anomalies de gestation déjà reportées. Ces changements du profil hormonal associés aux anomalies phénotypiques du placenta compromettent le déroulement normal de la gestation clonée et gênent le développement et le bien-être fœtal. Sur la base des observations faites sur le placenta de gestation clonée, le mécanisme moléculaire pouvant expliquer la disparition de l’épithélium du placenta (l’interface entre le tissue maternel et le placenta) a été étudié. L’étude a identifié des changements dans l’expression de deux protéines d’adhérence (E-cadhérin et β-catenin) de cellules épithéliales pouvant être associées aux anomalies du placenta chez les gestations clonées. Le tissu de cotylédons provenant de gestations clonées et contrôles a été analysé par Western blot, RT-PCR quantitatif, et par immunohistochimie. Les résultats présentaient une diminution significative (p<0.05) de l’expression des dites protéines dans les cellules trophoblastiques chez les gestations clonées. Le RT-PCR quantitatif démontrait que les gènes CCND1, CLDN1 et MSX1 ciblés par la voie de signalisation de la Wnt/β-catenin étaient significativement sous exprimés. La diminution de l’expression des protéines E-cadherin et β-catenin avec une réduction de l’activation de la protéine β-catenin durant le période d’attachement de l’embryon peut potentiellement expliquer l’absence totale ou partielle de l’attachement des membranes fœtales au tissu maternel et éventuellement, l’insuffisance placentaire caractéristique des gestations clonées chez la vache. La caractérisation morphologique et fonctionnelle du placenta durant les gestations clonées à haut risque est essentielle pour évaluer le statut de la gestation. Les résultats de la présente étude permettront de prédire le développement et le bien-être fœtal de façon critique à travers un protocole standardisé et permettre des interventions médicales pour améliorer le taux de succès des gestations clonées chez les bovins. / Although somatic cell nuclear transfer (SCNT) has been shown to be successful, there are still problems with this technique that is inhibiting its use in industry. Altered placental formation and development results in the high incidence of pregnancy loss and prenatal morbidity and mortality found in SCNT pregnancies. The objective of the initial study was to characterize morphological changes in fetal membranes of a group of bovine recipients carrying cloned fetuses and comparing them with control AI fetuses at various stages of gestation. Several morphological anomalies of placentomes such as edematous chorioallantoic membrane, hyper-echodense spikes or irregularities in the amniotic membrane as well as the pathological presence of degenerated inflammatory cells accompanied by disappearance of the placental epithelium were observed. It was concluded that these anomalies compromise fetal development. The results of this work also showed that ultrasonography may be a reliable technique to monitor and to characterize the placental changes in bovine pregnancies that can be used to assess fetal well-being. The next study compared the functionality of the placenta of cloned fetuses with controls. The concentration of three steroids (progesterone (P4), estrone sulphate (E1S), and estradiol (E2)) and pregnancy-specific protein B (PSPB) in maternal peripheral circulation were assessed and their associations with gestational anomalies were determined. The hormones profiles in the SCNT recipients deviated from the control group at certain stages of pregnancy. We observed higher concentrations of E2 throughout the study period, lower levels of P4 at day 80 as well as elevated PSPB concentrations at day 150 in SCNT recipients which coincided with high rate of abortion in these animals shortly after this stage. So, it is proposed that these hormonal changes together with the morphological anomalies of the placenta result in compromised fetal development. Finally, the molecular mechanism that could be responsible for the abnormal disappearance of the epithelial layer observed in SCNT placenta was investigated. To do so, we measured the expression of two major epithelial adherens junction proteins (E-cadherin and β-catenin) and determined if their expression is altered in relation to the aberrant placentation in SCNT embryos. Cotyledonary tissues from SCNT gestations and control pregnancies were analyzed by Western blot, quantitative RT-PCR and immunohistochemical analysis. Both candidates were significantly (P < 0.05) under-expressed in SCNT trophoblast cells at the protein level. Also, qRT-PCR confirmed that the Wnt/β-catenin signaling pathway target genes CCND1, CLDN1 and MSX1 were significantly down-regulated in SCNT placentas. So, we inferred that impaired E-cadherin and β-catenin protein expression, along with defective β-catenin signaling during embryo attachment, specifically in the window of placentation, results in loose attachment and contributes to insufficient placentation in bovine SCNT-derived embryos. Overall, we concluded that during the high-risk pregnancy of cloned fetuses, characterization of the morphological and functional changes of the placenta is critical to enable us to predict normal fetal development and wellbeing through a standardized procedure during clone gestations and to intervene medically in emergency cases to improve the overall efficiency of cloning in cattle.

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Maternal health has been found to lag significantly behind in medical innovations compared to other branches of medicine such as radiology. Prenatal care, being part of maternal health, seems to be no different. Driven by this fact, this study first attempts to investigate the state of innovation implementation within the context of prenatal care in Sweden. Then, it continues with the identification of critical barriers and facilitators for the implementation of medical innovations within the same field and context as medical innovations are at some point necessary. Considering the nature of the issues at hand a qualitative study was deemed more suitable and hence was conducted. The overall work consists of a literature review alongside a planned and executed empirical study. The empirical study was conducted as a single case study comprising of three stakeholder groups that were of interest. These were: doctors, midwives, and healthcare managers. Participants were approached using a combination of convenience and snowball sampling. A series of semi-structured interviews were conducted with actors located throughout Sweden. With the help of thematic analysis, a holistic view supported by all three stakeholder groups was able to arise leading to multi-faceted insights. Results show that the medical innovation implementation state within prenatal care in Sweden could have been characterised as lethargic before the arrival of the COVID-19 pandemic as no significant medical innovations had emerged in the field until then. However, it is discovered that COVID-19 signalled the end of this reality and abruptly moved the existing innovation implementation climate. Furthermore, regarding the potential introduction of medical innovations in prenatal care, important barriers and facilitators were discovered. The findings of the study can be of use to actors attempting to implement medical innovations in the future within prenatal care or other clinical areas and contexts.