Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2009.

Thesis (M. Med. Sc.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 74-83).

published_or_final_version / Obstetrics and Gynaecology / Master / Doctor of Medicine

Background: Gestational diabetes mellitus (GDM) is carbohydrate intolerance resulting in hyperglycemia of variable severity with onset or first recognition during pregnancy. Although GDM is asymptomatic in most patients, it will lead to adverse perinatal outcomes such as macrosomia and postpartum hemorrhage, birth injury and increased cesarean section rate. Identifying populations at high risk of GDM will allow for proper interventions and may thus improve the adverse perinatal outcomes. In 2010, the International Association of Diabetes and Pregnancy Study Groups (IADPSG) developed new diagnostic criteria for GDM. Mild hyperglycemia according to the previous criteria such as the WHO criteria and NDDG criteria is now categorized as GDM by the IADPSG Criteria. However, there are more and more controversies on the effectiveness of the IADPSG Criteria since it was implemented. China has relatively high prevalence of GDM, and the prevalence will be much higher by using the IADPSG Criteria. Given the uncertainty of the effectiveness of the IADPSG Criteria, it is important to examine the potential harms or benefits of the IADPSG Criteria in China by examining the adverse perinatal outcomes. Objectives:(1) To assess the difference in pregnancy outcomes in a cohort of Chinese women before and another cohort after implementing the IADPSG Criteria.(2) To examine whether the intervention to the mild hyperglycemia group improved pregnancy outcomes. Setting: Guangzhou Women and Children’s Medical Center (GZWCMC). Methods: A historical cohort study was conducted to investigate the difference of adverse pregnancy outcomes of the GDM patients after the IADPSG Criteria was adopted in the GZWCMC. 114 pregnant women with overt diabetes and 244 pregnant women with mild hyperglycemia in 2010 were sampled from the cohort of 2010 when the IADPSG Criteria had not been applied. 121 pregnant women with overt diabetes and 195 pregnant women with mild hyperglycemia were sampled from the cohort of 2012 when the IADPSG Criteria had been applied. Data was collected from the medical records in the medical center. Comparison of adverse pregnancy outcomes between the overt diabetes patients in 2010 and in 2012 was performed to examine the variation of GDM outcomes over time. Comparison of adverse pregnancy outcomes between the mild hyperglycemic subjects in 2010 and 2012 was performed to examine the effectiveness of the interventions to the mild hyperglycemic subjects, because mild hyperglycemic subjects in 2010 did not receive interventions. Primary outcomes were large for gestational infant (LGA) and primary cesarean section. Binary logistic regression model was used to examine the differences of adverse outcomes with adjustment for potential confounders. Odds ratios (ORs) and P-values were used to demonstrate the relative risk and the significance of the results. Results: Baseline characteristics varied between the cohort of 2010 and cohort of 2012. Subjects in the 2012 cohort had lower body mass index (BMI), lower blood glucose and were diagnosed earlier. No differences of primary outcomes between the overt diabetes patients in 2010 and in 2012 were found after adjustment for maternal age, BMI, parity and gestational age at oral glucose tolerance test (OGTT). The OR for LGA and primary cesarean was 0.58 (95% confidence interval (CI):0.10-3.35, P=0.54) and 0.68 (95% CI: 0.33-1.39,P=0.29), respectively, suggesting that LGA and primary cesarean in overt diabetes patients did not vary over time. No differences of LGA and primary cesarean between the mild hyperglycemic subjects in 2010 and 2012 were observed after adjustment for maternal age, BMI, parity and gestational age at OGTT. The OR for LGA and primary cesarean section was 1.25 (95% CI: 0.46-3.40, P=0.66) and 0.78 (95% CI: 0.47-1.29, P=0.33), respectively. Compared with those with mild hyperglycemia in 2010, a lower risk for postpartum hemorrhage in those with mild hyperglycemia in 2012 was found (OR=0.05, 95% CI: 0.01-0.41). Conclusions: Our study has provided some evidence that the risks for most of the adverse pregnancy outcomes except postpartum hemorrhage, including LGA, primary cesarean, gestational hypertension, preterm birth, macrosomia and mean birth weight in pregnant women with mild hyperglycemia did not have significant differences before and after the IADPSG Criteria was adopted. Given the small sample size of the current study, we have yet to draw a definite conclusion that intervention to pregnant women with mild hyperglycemia improved adverse pregnancy outcomes from the results. Further large studies are needed to examine both the benefits and harms of implementing the IADPSG Criteria. / published_or_final_version / Public Health / Master / Master of Public Health

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

INTRODUCTION: In sub-Saharan Africa, access to care during pregnancy and child birth is an abiding challenge for many women. Many women face socioeconomic, cultural, and physical barriers while attempting to access healthcare facilities during pregnancy. These barriers often result in women accessing healthcare facilities after life-threatening complications develop, ultimately leading to high rates of maternal mortality. In Nigeria, several locally endemic diseases, such as malaria and HIV, impinge on population health. Having access to care during pregnancy provides an opportunity for prompt diagnosis, treatment, and prevention of common endemic disease. This dissertation focused on access to care during pregnancy in Nigeria by using two indicators: malaria parasitemia and Cesarean-section (CS). Therefore, this dissertation had two overarching goals. The first was to estimate the prevalence of malaria parasitemia during pregnancy and to determine maternal risk factors associated with high malaria parasitemia in Enugu State, Nigeria. The second was to establish the incidence of CS and to determine the socioeconomic and medical risk factors that are associated with having a CS among women in Enugu State, as well as in Nigeria as a whole. METHODS: Secondary analyses of two unique datasets––Healthy Beginnings Initiative (HBI) and the Nigerian Demographic and Health Survey (DHS)––were conducted. The HBI cohort study took place in Enugu State, Nigeria. The prevalence of peripheral malaria parasitemia in Enugu State was established within the context of HBI. Malaria parasitemia was scored according to the Malaria Plus System (0 to ++++). For this dissertation those in the 0 and + group were classified as low having parasitemia; while those in the ++ and +++ groups were classified as having high parasitemia. Person-level maternal risk factors that were associated with high malaria parasitemia were estimated using crude and adjusted logistic regression modeling with malaria parasitemia as the main outcome. The incidence of CS in Enugu State was also estimated within context of the HBI cohort. Socioeconomic and medical risk factors associated with having a CS in Enugu State, Nigeria were estimated. To investigate the extent to which the findings from the HBI represent the rates of CS in Nigeria as a whole, the Nigerian DHS was utilized. The Nigerian DHS was a cross-sectional study that was conducted throughout Nigeria. The incidence of CS in all of Nigeria was estimated. Socioeconomic and medical risk factors associated with having a CS were also investigated. Crude and adjusted logistic regression models with CS as the main outcome are presented. Weights were applied to all analyses conducted with the DHS to make the data representative at the county level. RESULTS: Over 99% of women in the HBI study tested positive for peripheral malaria parasitemia. For each additional person in the household, a 6% lower odds of high malaria parasitemia was found (p<0.05). Regarding CS, analyses of both datasets indicated that Nigeria has relatively low rates of CS compared to the World Health Organization's recommendations. In the HBI, 7.2% of women in Enugu State, Nigeria had a CS. Significantly lower odds of having a CS were observed among women who live in a rural setting compared to those who reside in an urban setting (p<0.05). Percentages of CS increased significantly as maternal age and/or education increased. HBI results demonstrated 53% higher odds of having a CS if participants had high malaria parasitemia compared to those with lower malaria parasitemia (p<0.05). Results of the DHS yielded even lower rates of CS with only 2.3% of women in Nigeria overall having had a CS during their last delivery. Consistent with analysis for Enugu State, in the DHS women living in rural areas had significantly lower odds of having a CS than those living in urban areas (p<0.05). Likewise, religion was significantly associated with having had a CS; Muslim women had 54% lower odds of having a CS compared to Catholics (p<0.05). Women who had health insurance and women who received prenatal care from a skilled birth attendant had increased odds of having a CS compared to women who did not have insurance and received no prenatal care (adjusted OR [aOR] 1.78: 95%CI 1.18-2.67, p<0.05; aOR 3.00: 1.51-5.96, p<0.05). DISCUSSION: Based on the high prevalence of malaria among women in the HBI study, education on best practices to prevent malaria during pregnancy, and resources in support of these practices are urgently needed. Likewise, low rates of CS in both Enugu State and across Nigeria indicate that Nigerian women may not have adequate access to obstetric care during delivery. Results from this dissertation also indicate that Nigerian women face barriers in obtaining adequate perinatal healthcare, ultimately perpetuating the cycle of high maternal mortality and gross health deficiencies that are common to Nigerian women.

No description available.

Uterine Natural Killer cells are the major lymphocyte population in the pregnant uterus in early gestation; outnumbering both T and B cells. The numerical expansion of uterine Natural Killer cells is thought to result from the expansion of preexisting progenitor cells resident to the uterus, recruitment of Natural Killer cells from the circulation, or a combination of both pathways. Uterine Natural Killer cells are capable of cytotoxic killing and express receptors that can recognize foreign paternal antigens. Therefore, it has been argued that uterine Natural Killer cell activation can lead to killing of fetal cells and abortion. However, fetal rejection by uterine Natural Killer cells does not occur in normal pregnancies and other functions for uterine Natural Killer cells have been proposed. These include: the regulation of maternal blood supply responsible for providing oxygen to the fetus, regulation of maternal blood pressure and, in species with invasive placentation, regulation of decidualization, the process of endometrial cell expansion and transformation during the menstrual cycle and during pregnancy. These cell functions juxtapose the concept that uterine Natural Killer cell activation is harmful to the fetus and offer a new perspective that uterine Natural Killer cells regulate functions unrelated to traditional transplantation immunology. In this dissertation, work is presented showing that uterine Natural Killer cells express molecules which regulate blood pressure and decidualization. Also presented are data supporting the hypothesis that the numerical increase of uterine Natural Killer cells is due to the recruitment of Natural Killer cells from the blood. These results support roles for uterine Natural Killer cells other than cytotoxic killing and advance the understanding of uterine Natural Killer cells as dynamic players that support pregnancy-associated biological processes unrelated to traditional understandings of immune surveillance. / Thesis (Master, Microbiology & Immunology) -- Queen's University, 2009-12-15 11:33:37.11

Diabetic pregnant women have an increased risk of developing pre-eclampsia, a late gestational syndrome, although the reason for this gain is unknown. Placental pathology in pre-eclampsia is linked with insufficient spiral arterial modification, a process triggered by uterine natural killer (uNK) cells, an abundant pro-angiogenic cell type found in early pregnancy decidua (endometrium of the pregnant uterus). UNK cells effect spiral arterial modification, the blood supply to the placenta, through the release of interferon gamma (Ifng), a pro-inflammatory cytokine. Peripheral blood precursors of uNK cells employ a unique pattern of homing molecules to traffic to the decidua. The goal of this thesis was to advance the understanding of how homing and functions of uNK cell precursors might be modified in diabetic pregnancy. Studies employed both murine and human models. Pregnancies were studied microscopically in normoglycemic (n-) and hyperglycemic (d-) non-obese diabetic (NOD) and NOD.Ifng-/- (NOD strain with a genetic deletion of Ifng) mice. Pre-implantation embryo development was impaired in n- and d-NOD.Ifng-/- mice. Hyperglycemia decreased both numbers of uNK cells and spiral artery remodelling within d-NOD and d-NOD.Ifng-/- decidua. This decrease in spiral artery remodelling was independent of Ifng and linked with hypertrophy of smooth muscle in implantation sites. Blood leukocytes from control and diabetic pregnant women were evaluated for adhesive function and expression of key homing molecules. Diabetic leukocytes had decreased CD56+ (uNK cell lineage) cell adhesion to decidua, increased CD56+ cell adhesion to pancreas, and comparable adhesion to lymph node compared with control leukocytes, suggesting impaired decidual homing in vivo. Of 8 lymphocyte subsets resolved by flow cytometry, type 1 cytokine CD56bright cells expressed appropriate homing molecules most abundantly. Diabetes did not alter levels of expression of these receptors. These data show that diabetes alters the potential capacity for decidual homing of pre-uNK cells but that this is not achieved through reduction in levels of key homing molecules. Diabetes also reduced spiral arterial modification in mice through hypertrophy of smooth muscle. The reproductive challenges of diabetic women who have co-morbid immunological diseases merit further study. / Thesis (Master, Anatomy & Cell Biology) -- Queen's University, 2011-01-30 23:46:23.151

No description available.