Title: Is maternal hypotension during pregnancy and/or posterior located placenta associated with increased risk of stillbirth? Design: A retrospective case-controlled study comparing a group of stillbirths with a live born control group matched for maternal age, baby gender, gestational age and year of birth. The purpose of this study was to ascertain whether hypotensive women or women with a posterior located placenta are at increased risk of stillbirth. Two Australian tertiary referral obstetric hospitals were chosen as participating hospitals for this study. All cases with a discharge diagnosis of stillbirth over a five year period at these hospitals were identified and considered as cases for inclusion in the study. An attempt was made to match each case with two controls. After exclusions there were 124 cases and 243 controls. Blood pressure (BP) readings throughout pregnancy were extracted from the medical record of each subject, and summary 'exposure' measures were created. These included: diastolic and systolic readings as well as mean arterial pressure taken at the initial (booking BP), minimum, calculated average, and final reading prior to the birth. Placental position, as determined by midtrimester ultrasound, was also collected. Results: This study found that low Diastolic Blood Pressure (DBP) readings (between 60-70mmHg) throughout pregnancy were associated with a statistically significant increased risk of stillbirth. This trend was seen from the initial reading at booking (OR 1.83 95% CI 1.0-3.2, p=0.03) through to the last taken before the birth (OR 1.53 95% CI 0.9-2.5, p=0.09) including the calculated average over the course of the pregnancy (OR 1.61 95% CI 1.0-2.6, p=0.05) and minimum observed during the pregnancy (OR 2.94 95% CI 0.98-8.8, p=0.05). In addition, this study found a minimum diastolic reading of less than 60mmHg carries a significant risk of stillbirth with a crude odds ratio of 3.5 (95% CI 1.18-10.41, p=0.02). This study did not show a statistically ignificant association of systolic hypotension with stillbirth. However, after combining both systolic and diastolic blood pressures to calculate the mean arterial blood pressure (MAP) the analysis did suggest that women with a minimum MAP between 73-83mmHg were at increased risk of stillbirth (OR 1.69 CI 1.02-2.81, p=0.04). Furthermore, this study found that three MAP readings of less than 83.3 during the course of the pregnancy carries almost twice the risk of stillbirth (adjusted OR 1.99) even after adjusting for race, gravidity, parity, BMI and SGA (and matching for maternal age, gestational age, gender and year of birth.) Women who have a posterior located placenta were statistically more likely to suffer a stillbirth than women who had a placenta in any other position (crude OR 1.64) and this estimate was largely unaffected by adjustment for blood pressure and other putative risk factors (adjusted OR 1.67) Conclusion: In conclusion, this is the first study which specifically examined a stillborn population in order to explore whether maternal hypotension and posterior located placenta impact negatively on stillbirth incidence and the results of this study suggest that both maternal hypotension and posterior located placenta are probably independent contributory risk factors for stillbirth. This means that maternity care providers should closely manage and monitor progress of women who are hypotensive during pregnancy or those whose placenta is posterior; and that effective management strategies need to be developed to care for these women. / Thesis (Ph.D.)--School of Population Health and Clinical Practice, 2007.

Thèse d'exercice : Médecine : Nancy 1 : 2008. / Titre provenant de l'écran-titre.

Title: Is maternal hypotension during pregnancy and/or posterior located placenta associated with increased risk of stillbirth? Design: A retrospective case-controlled study comparing a group of stillbirths with a live born control group matched for maternal age, baby gender, gestational age and year of birth. The purpose of this study was to ascertain whether hypotensive women or women with a posterior located placenta are at increased risk of stillbirth. Two Australian tertiary referral obstetric hospitals were chosen as participating hospitals for this study. All cases with a discharge diagnosis of stillbirth over a five year period at these hospitals were identified and considered as cases for inclusion in the study. An attempt was made to match each case with two controls. After exclusions there were 124 cases and 243 controls. Blood pressure (BP) readings throughout pregnancy were extracted from the medical record of each subject, and summary 'exposure' measures were created. These included: diastolic and systolic readings as well as mean arterial pressure taken at the initial (booking BP), minimum, calculated average, and final reading prior to the birth. Placental position, as determined by midtrimester ultrasound, was also collected. Results: This study found that low Diastolic Blood Pressure (DBP) readings (between 60-70mmHg) throughout pregnancy were associated with a statistically significant increased risk of stillbirth. This trend was seen from the initial reading at booking (OR 1.83 95% CI 1.0-3.2, p=0.03) through to the last taken before the birth (OR 1.53 95% CI 0.9-2.5, p=0.09) including the calculated average over the course of the pregnancy (OR 1.61 95% CI 1.0-2.6, p=0.05) and minimum observed during the pregnancy (OR 2.94 95% CI 0.98-8.8, p=0.05). In addition, this study found a minimum diastolic reading of less than 60mmHg carries a significant risk of stillbirth with a crude odds ratio of 3.5 (95% CI 1.18-10.41, p=0.02). This study did not show a statistically ignificant association of systolic hypotension with stillbirth. However, after combining both systolic and diastolic blood pressures to calculate the mean arterial blood pressure (MAP) the analysis did suggest that women with a minimum MAP between 73-83mmHg were at increased risk of stillbirth (OR 1.69 CI 1.02-2.81, p=0.04). Furthermore, this study found that three MAP readings of less than 83.3 during the course of the pregnancy carries almost twice the risk of stillbirth (adjusted OR 1.99) even after adjusting for race, gravidity, parity, BMI and SGA (and matching for maternal age, gestational age, gender and year of birth.) Women who have a posterior located placenta were statistically more likely to suffer a stillbirth than women who had a placenta in any other position (crude OR 1.64) and this estimate was largely unaffected by adjustment for blood pressure and other putative risk factors (adjusted OR 1.67) Conclusion: In conclusion, this is the first study which specifically examined a stillborn population in order to explore whether maternal hypotension and posterior located placenta impact negatively on stillbirth incidence and the results of this study suggest that both maternal hypotension and posterior located placenta are probably independent contributory risk factors for stillbirth. This means that maternity care providers should closely manage and monitor progress of women who are hypotensive during pregnancy or those whose placenta is posterior; and that effective management strategies need to be developed to care for these women. / Thesis (Ph.D.)--School of Population Health and Clinical Practice, 2007.

Thesis (M.S.)--University of Michigan, 1972.

Thesis (M.S.)--University of Michigan, 1972.

A research report submitted to the Faculty of Medicine, University of Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Medicine in the branch of Anaesthesia. / Spinal anaesthesia for Caesarean section is associated with an unacceptably high incidence of hypotension despite the administration of an intravenous fluid preload and the use of uterine displacement. The theoretical benefits of preventing hypotension as opposed to treating it as it occurs are the avoidance of considerable maternal discomfort, a reduced risk of serious cardiovascular or respiratory depression and the avoidance of transient foetal asphyxia. The use of prophylactic intramuscular ephedrine prior to spinal anaesthesia has been recommended but not well studied. The advantages of the intramuscular route for ephedrine administration are its simplicity and its favourable pharmacokinetic profile. Cardiovascular support is sustained throughout the surgery and into the post operative period. Opposition to the use of intramuscular ephedrine in the prevention of hypotension is based on two studies in which spinal anaesthesia was not used [1,2]. These studies showed an unacceptably high incidence of hypertension, a deleterious effect on foetal gas exchange and a lack of efficacy when intramuscular ephedrine was used in epidural and general anaesthesia respectively. This research report describes a randomised, double blind, interventional study designed to assess the safety (prevalence of hypertension, tachycardia or foetal compromise) and efficacy (prevalence of hypotension) of 37,5mg of ephedrine given prior to spinal anaesthesia for Caesarean section. Forty patients who had given informed consent were entered into the study. Blood pressures and pulse rates were recorded for 90 minutes after ephedrine administration, samples of umbilical venous blood were collected and Apgar scores assessed. This study found that giving 37,5mg of intramuscular ephedrine prior to spinal anaesthesia was safe from a maternal point of view in that it was not associated with reactive hypertension or tachycardia. When the ephedrine was given 10 minutes prior to induction of the spinal the technique proved to be effective in reducing the incidence and severity of hypotension. When used in the above manner the technique was not associated with foetal depression or acidosis. / WHSLYP2016

by James Sui-kiu Sham. / Bibliography: leaves 132-145 / Thesis (M.Phil.)--Chinese University of Hong Kong, 1983

Thesis (M.S.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 44-54).

Thesis (Ph.D.) --University of Adelaide, School of Medicine, Discipline of Medicine, 2007. / "December 2006" Bibliography: leaves 252-297. Also available in print form.

Thesis (M.S.)--University of Wisconsin--La Crosse, 2002. / Includes bibliographical references.