Abstract not available

Includes bibliographical references (leaves 228-257). Aims to determine the impact of maternal undernutrition during late gestation and during the periconceptional and gestational periods on fetal growth, fetal blood pressure and the fetal hypothalamo-pituitary adrenal axis in the sheep.

RÉSUMÉ Les protéines associées à la gestation (PAGs) constituent une grande famille de protéinases aspartiques exprimées dans les cellules épithéliales de la couche superficielle du placenta des artiodactyles et plus précisément dans les granules des cellules binucléées. Des investigations par biologie moléculaire (clonage et séquençage) ont permis de montrer que les protéines de la gestation font partie de la grande famille des protéases aspartiques tout comme le pepsinogène, la pepsine, la chymosine, les cathepsines D et E, et la rénine. La détermination des concentrations en PAG par radioimmunoassay dans le sérum ou dans le plasma est actuellement employée comme méthode sérologique spécifique pour le diagnostic de gestation chez le bovin dès le 28e jour après la conception. Au-delà de ce délai, les dosages des PAGs peuvent également être utilisés pour assurer le suivi de la gestation notamment dans le cadre de létude de la mortalité embryonnaire précoce ou tardive et de la mortalité ftale. Au moment dentreprendre nos investigations expérimentales, une attention particulière a été portée à notre maîtrise des systèmes de dosages radioimmunologiques notamment dans les zones des faibles concentrations de PAG caractérisant le premier trimestre de la gestation chez les bovins. Cest ainsi que les deux premières études sur lesquelles repose ce travail de thèse ont visé à tester de nouveaux antisérums dirigés contre la PAG et à comparer leurs performances en milieu sérique ou plasmatique. Ensuite, cinq différents systèmes de dosages (utilisant différents antisérums) ont été comparés quant à leur sensibilité, spécificité, exactitude des diagnostics positifs et exactitude des diagnostics négatifs, sur des séries de plasmas provenant de femelles non gestantes et de femelles gestantes durant le premier trimestre de la gestation. Dans une troisième étude, les concentrations de PAG, LH et prolactine ont été interprétées en fonction dune classification basée sur le niveau de progestérone mesuré chez les femelles à jour 21. Dans la première étude, lobjectif a été de déterminer les paramètres de limite minimale de détection, reproductibilité, exactitude, spécificité et parallélisme des dilutions caractérisant les cinq systèmes radioimmunologiques différents : RIA-497, RIA-706, RIA-780, RIA-809 et RIA-Pool. Ensuite, leur capacité à distinguer les femelles non gestantes et gestantes prélevées au 30e jour suivant linsémination artificielle a été analysée dans le détail. Létude a été menée sur un effectif de 40 femelles de race Holstein-Frisonne dâge et de parité mélangés dont la gestation a été confirmée par exploration rectale réalisée entre le 2e et le 3e mois après linsémination. Un groupe contrôle composé de dix vaches maintenues en stabulation entravée confirmées non gestantes par examen échographique et exploration rectale a été utilisé simultanément. Les caractéristiques générales des différents systèmes étaient satisfaisantes. Leur spécificité était excellente à lexception du système RIA-809 ayant montré une très légère interférence de lacide syalique et de lhCG. Les concentrations mesurées dans le plasma des femelles non gestantes sont restées inférieures à 0,5 ng/mL excepté celles qui étaient mesurées dans les systèmes RIA-780 et RIA-809. Seuls les systèmes RIA-497, RIA-706 et RIA-Pool ont fourni des valeurs de sensibilité, spécificité, exactitude des diagnostics positifs, exactitude des diagnostics négatifs égales à 100%. Dans la deuxième étude, les cinq systèmes de dosage ont été utilisés pour déterminer les concentrations de PAG dans le plasma aux jours 30, 45, 60 et 80. Les corrélations ont été calculées entre les systèmes ainsi que les rapports de concentrations mesurées par chacun deux : les systèmes RIA-706, RIA-780, RIA-809 et RIA-Pool ont révélé des valeurs plus élevées que le RIA-497 à tous les stades étudiés. La troisième étude a visé à vérifier une hypothèse formulée à plusieurs reprises par différents auteurs : le niveau de concentration en progestérone atteint en début de gestation est-il susceptible dinteragir avec les concentrations de protéines trophoblastiques, de LH et de prolactine mesurées plus tard durant le premier trimestre de la gestation ? Dans cette étude, nous avons déterminé les concentrations de lensemble des paramètres sur les prélèvements correspondant aux jours 0, 21, 30, 45, 60 et 80 de 37 femelles gestantes. Les femelles ont été réparties en deux sous groupes : celles dont la progestérone au jour 21 était inférieure à la moyenne (Low-P4) et celles dont la même progestérone était supérieure à la moyenne au jour 21 (High-P4). Lorsque les deux sous groupes ont été suivis aux périodes ultérieures (jours 30, 45, 60 et 80), il est apparu que les concentrations de PAG ont eu tendance à être plus élevées dans tous les systèmes chez les vaches du groupe High-P4. Une différence significative est atteinte en utilisant le RIA-497 au jour 80. Les concentrations en LH et prolactine ont eu tendance à être plus faibles à toutes les périodes chez les vaches faisant partie du groupe High-P4. La différence a été significative pour la LH à jour 60 et pour la prolactine à jour 21. Dans leur ensemble, les résultats de ce travail montrent que le diagnostic de gestation peut être amélioré (sensibilité, spécificité, exactitude des diagnostics positifs, exactitude des diagnostics négatifs) en sélectionnant soigneusement les antisérums et en les mélangeant de façon appropriée. Ces systèmes sont utilisables pour suivre les concentrations de PAG durant le premier trimestre de la gestation, les résultats étant fortement corrélés tout en montrant des profils différents. Associées au dosage de la progestérone, de la LH et de la prolactine, les investigations sur les PAGs permettent de progresser dans létude des régulations qui relient lhypophyse, les gonades et le trophoblaste durant le premier trimestre de la gestation. SUMMARY Pregnancy Associated Glycoproteins (PAGs) constitute a large family of aspartic proteinases expressed in the outer epithelial cells layer of the placenta of eutherian species and more precisely in the granules of the binucleate cells. Investigations by molecular biology (cloning and sequencing) showed that the PAGs are part of the great family of the aspartic proteases like pepsinogen, pepsin, chymosin, cathepsins D and E, and renin. The determination of the concentrations in PAG by radioimmunoassay in serum or plasma is currently used as specific serological method for the diagnosis of gestation at day 28 after conception. Beyond this time, PAGs assays can also be used to ensure the follow-up of gestation in particular during the study of early or late embryonic mortality and early foetal mortality. When we started our experimental investigations, a special attention was paid to our control of radioimmunoassay systems especially in the zones with low concentrations of PAG which characterize the first trimester of bovine gestation. Thus the first two studies on which this work was based, aimed testing new antisera raised against PAG, and comparing their performances in seric or plasmatic medium. Then, five various assays (using different antisera) were compared as for their sensitivity, specificity, exactitude of the positive diagnoses and exactitude of the negative diagnoses, on series of plasmas from nonpregnant and pregnant females during the first trimester of gestation. In a third study, the concentrations of PAG, LH and prolactin were interpreted according to a classification based on the progesterone level measured in females at day 21. In the first study, the objective was to determine the parameters of minimal limit of detection, reproducibility, exactitude, specificity and parallelism of dilutions characterizing the five different radioimmunoassay systems: RIA-497, RIA-706, RIA-780, RIA-809 and RIA-Pool. Then, their capacity to discriminate non-pregnant and pregnant females investigated at day 30 after artificial insemination was also analyzed in detail. The study was undertaken on 40 Holstein-Friesian females of different age and parity, and whose gestation was confirmed by rectal exploration carried out between the second and the third month after insemination. A control group of ten cows maintained in stabling, confirmed non-pregnant by ultrasonography and rectal exploration, was used simultaneously. The general characteristics of the various systems were satisfactory. Their specificity was excellent except for system RIA-809 which shown a small interference of syalic acid and hCG. The concentrations measured in the plasma of non-pregnant females remained lower than 0.5 ng/mL except those which were measured in systems RIA-780 and RIA-809. Only the systems RIA-497, RIA-706 and RIA-Pool provided values of sensitivity, specificity, exactitude of the positive diagnoses, exactitude of the negative diagnoses equal to 100%. In the second study, all five systems were used in order to determine the concentrations of PAG in plasma at days 30, 45, 60 and 80. The correlations were calculated between the systems as well as the ratios of concentrations measured by each one of them: systems RIA-706, RIA-780, RIA-809 and RIA-Pool revealed higher values than the RIA-497 at all the studied stages. The third study aimed to check a hypothesis formulated by various authors: is the concentration level of progesterone reached at beginning of gestation likely to interact with the concentrations of trophoblastic proteins, LH and prolactin measured later during the first trimester of gestation ? In this study, we determined concentrations of the whole parameters on samples corresponding to days 0, 21, 30, 45, 60 and 80 of 37 pregnant females. The females were divided into two groups: those whose progesterone at day 21 was lower than the average (Low-P4) and those whose progesterone was higher than the average at day 21 (High-P4). When both groups were investigated at later periods (days 30 and 80), it appeared that the concentrations of PAG tended to be higher in all systems in the cows of the High-P4 group. A significant difference was raised by using RIA-497 at day 80. The concentrations in LH and prolactin lead to be weaker during all the periods in the cows of the High-P4 group. The difference was significant for LH at day 60 and for prolactin at day 21. In conclusion, the results of this work show that the diagnosis of gestation can be improved (sensitivity, specificity, exactitude of the positive diagnoses, exactitude of the negative diagnoses) by selecting the antisera carefully and by mixing them in a suitable way. These systems are usable to follow the concentrations of PAG during the first trimester of gestation, the results are strongly correlated while showing different profiles. Combined to assays of progesterone, LH and prolactin, the investigations on PAGs make progress in the study of the regulations between pituitary gland, gonads and the trophoblast during the first trimester of gestation.

<p>This study aimed to explore the attitudes to HIV testing among a group of black, low socio-economic status pregnant women from Gugulethu, South Africa. The key research interest was to evaluate the attitudes and understandings of HIV/AIDS that underpin the decision to comply or not comply with prenatal HIV testing. Theories of health behaviour concur that the extent to which an individual will engage in a given health behaviour, such as HIV test compliance, will be a function of the extent to which a person believes she is personally susceptible to the particular illness and her evaluation of the severity of the consequences of contracting the disease.</p>

The aim of this thesis was to determine any association between plasma oxytocin and vasopressin concentrations and renal water and sodium excretion during normal pregnancy. In addition to investigate changes in concentrations of estradiol, progesterone, oxytocin, cortisol, and glucose in the blood before and in the nearest hours after delivery and if treatment with oxytocin affected these concentrations and the fluid balance during the different stages of labour. Oxytocin, vasopressin, estradiol, progesterone, and cortisol were analysed in blood plasma or serum by radioimmunoassay or ELISA: serum glucose, and osmolality, and sodium in plasma and urine were  analysed by standard laboratory techniques. Fifty-seven women were studied during pregnancy and fifty-one during parturition and post partum. The low plasma vasopressin and increasing plasma oxytocin concentrations with unchanged water and sodium excretion indicate that oxytocin assists vasopressin in concentrating urine during pregnancy. Plasma vasopressin concentration continued to be low during parturition and post partum. Urine flow and concentration was unrelated to changes in plasma sodium concentration, indicating regulation of fluid balance during parturition was different to the non-gravid state. Women with weak myometrial contractions during parturition (slow progress of labour) reacted differently than women with normal parturition and a group of women with fast progress of labour. The group with slow labour had lower serum estradiol concentration in the latency phase and became hyponatremic. Pulsatile and continuous oxytocin infusions were both effective in the treatment of slow progress of labour. A lower amount of oxytocin was needed to affect delivery when given as pulsatile infusion. Serum cortisol and glucose concentrations were high during labour and cortisol level remained elevated after delivery and glucose concentration reached the highest levels (12 mmol/L) at the same time. Insulin resistance together with the long time of elevated cortisol concentration partly explained the high glucose concentration. In conclusion, fluid balance is not regulated according to the usual sensitive osmotic and volumetric influence on vasopressin release from the neurohypophysis during pregnancy and parturition. Parturition involves a change from one demanding condition, pregnancy, to another, lactation. Parturition and the hours directly after delivery are a turbulent period involving considerable stress.

Background: Pre-eclampsia (PET) is one of the major causes of maternal and neonatal morbidity and mortality1. Misclassification of PET can lead to biased or erroneous results in epidemiologic studies resulting in false conclusions. Objectives: The objectives of this thesis are to determine the validity of PET diagnosis in pregnant women in administrative database using the ICD-10-CA codes, to explore the nature of misclassification, and to estimate whether misclassification of PET diagnosis in administrative database may result in biased conclusions. Methods: Pregnant women who participated in the Ottawa and Kingston (OaK) Birth Cohort study and delivered in the Ottawa Hospital were included in the study. All cases with hypertensive disorder of pregnancy in the study population were adjudicated to confirm diagnosis of PET. This adjudicated dataset was used as a reference standard. The PET incidence in hospital discharge database was compared with PET incidence calculated from the reference standard database. Results: 2887 of the requested charts were available for review. The PET incidence was much lower in administrative database (1.47%) than in the OaK Birth Cohort Study (3.6%). The results of the study demonstrated that hospital discharge database via ICD-10-CA was not very sensitive to determine incidence of PET since sensitivity of ICD-10-CA diagnostic codes for PET was low (35.92% with 95% Confidence Intervals (CI): 26.7; 45.9) but specificity, PPV, and NPV were high. The majority of misclassified cases belonged to the category (according to the proposed classification) “PET pregnancies coded with incorrect ICD-10-CA code” (78.88%) followed by the category “Pregnancies affected by PET coded as normal” (14.08%). Conclusion: Using hospital discharge database and ICD-10-CA coding to determine incidence of PET in certain settings may yield low sensitivity. Researchers should validate the results when using the hospital discharge database for PET research to ensure that the findings based on analyses of such data demonstrate what they claimed to demonstrate.

This dissertation examines the construct of hope and its ability to be taught to pregnant and parenting adolescents as a strategy to improve academic achievement and dissuade repeat adolescent pregnancy. A systemic review of the literature examined fourteen (n=14) empirical studies to ascertain if a relationship existed between achievement and the construct of hope. With 92% of the studies reporting a positive correlation between hope and achievement, one can answer yes to the question of an existing relationship between hope and achievement. A manuscript is presented to summarize the development and implementation of a curriculum, designed to develop requisite skills among adolescent mothers to elevate their levels of hope. The Helping Optimize Planning Efforts (HOPE) curriculum presents specific methods for adolescent mothers to enhance skills related to goal setting, goal attainment and the use of positive self-talk as a mechanism for developing hope or increasing existing levels of hope. The study attempted to assess the ability of the HOPE curriculum to enhance the adolescent mother?s level of hope with the underlying assumption that increasing levels of hope might decrease the probability of a repeat adolescent pregnancy. Findings suggested there was a significant difference in the scores for the Dispositional Trait Hope Scale (DTHS) pre-test (M = 68.5, SD = 7.0) and the DTHS post-test scores (M = 73.2, SD = 5.61) (t(11) = 3.18, p = .009) indicating an increase in global hope. A significant difference was also found in between the State Hope Scale (SHS) pre-test scores (M = 39.0, SD = 4.84) and SHS post-test scores (M = 41.5, SD = 5.21) (t(11) = 4.19, p = .002) indicating an increase in the students point in time level of hope. The evaluation of the curriculum indicated that adolescent mothers can be taught to increase their levels of hope using the HOPE curriculum. Data collected during the evaluation of the HOPE curriculum was further analyzed to identify the constructs that contribute to the building of hope in adolescent mothers. The data suggests that two distinct components, agency and pathway, contribute to increase the level of hope. Examination of the subscales within the DTHS, showed there was a significant difference between the pre-test agency (M = 25.42, SD = 5.81) and the post-test agency scores (M = 27.85, SD = 3.65) (t(11) = 2.83, p = .017). Also, among the DTHS pathway subscale, a significant difference was found between the scores on the pre-test (M = 25.08, SD = 3.58) and the post-test score (M = 26.67, SD = 2.35) (t(11) = 2.22, p = .048). These findings suggest that the increased level of hope on the DTHS for was a reflection of the improvements in components, agency and pathway. These findings suggests that adolescent mothers can be taught to be more hopeful when the components of agency and pathway are developed.

This retrospective case-control study was designed to investigate the relationship between placental localization and intrauterine growth restriction (IUGR). Pregnant women with an anatomic survey from January 1, 2000, to December 31, 2005, and delivery of the pregnancy at Yale-New Haven Hospital (YNHH) were identified using clinical and billing records. Multiple gestation, fetal anomaly, and incomplete medical information were reasons for exclusion. Cases (N=69) were consecutive pregnancies with evidence of IUGR (estimated fetal weight <10th percentile for gestational age) at last follow-up ultrasound. Randomly selected controls (N=258) from the same time period had no evidence of IUGR. Maternal, ultrasound, delivery, and perinatal data were collected by retrospective medical record review, and IUGR cases and non-IUGR controls were compared using the Students t-test, Wilcoxon test, Chi-square analysis, Fishers exact test, and ANOVA. Placental location was determined from the anatomic survey record (obtained at 18.4 ± 1.2 weeks gestation in the IUGR group and 18.2 ± 1.0 weeks gestation in the control group; P=0.18). Multivariate logistic regression with adjustment for confounders was used to investigate the association between IUGR and placental localization. Consistent with known predictors of IUGR, the IUGR group had a higher proportion of black women (36.4% vs. 19.8%, P=0.03), chronic hypertension (26.0% vs. 3.5%, P<0.001), and hypertensive disorders of pregnancy (36.2% vs. 5.0%, P<0.001). Mean birth weights of IUGR and non-IUGR pregnancies differed by 2 kilograms (3244 ± 625 grams vs. 1277 ± 637 grams, P<0.001). IUGR infants were more likely to receive antenatal steroids, deliver preterm, deliver by cesarean section, and be admitted to neonatal intensive care. In both IUGR and non-IUGR pregnancies, the placenta was most commonly anterior or posterior. Unilateral placentas were three times more common in the IUGR group than in the non-IUGR group (17.4% vs. 5.0%, P=0.01). IUGR pregnancies were over four times as likely as control subjects to have unilaterally-located placentas compared to anterior placentas (OR 4.8, 95% confidence interval, 1.9-11.7). Adjusting for ethnicity, chronic hypertension, and hypertensive disorders of pregnancy did not affect this finding (OR 4.6, 95% confidence interval 1.6-13.5). In conclusion, we compared a group of 69 IUGR pregnancies to 258 non-IUGR controls and found intrauterine growth restriction to be associated with unilateral placentation.

Thesis (Ph. D.)--University of Missouri--Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 285-308).

Thesis (MTech. degree in Nursing)--Tshwane University of Technology, 2010. / Teenage pregnancy is a major public health problem for this age group in many countries. The consequences of early childbearing are a reduced likelihood of school completion and a decreased opportunity of a high earning career. The motivation of this study was twofold, the increase in the terminations of pregnancies in Soshanguve and the lack of guidelines for health professionals to prevent teenage pregnancy. The research question for the study was using the Johnson Behavioural System Model as basis.