Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [238]-247).

No description available.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 69-103).

Thesis (Ph.D.)--Australian National University, 2004.

Due to rapid growth in computing power, the collection of high dimensional and complex datasets is increasingly feasible. To reap their full benefit, novel analytic strategies may be required. Application of such methods remains limited in certain epidemiologic research areas. The overarching aim of this dissertation was to apply novel analytic strategies with close ties to causal inference and statistical learning theory to gain new insights into well-studied areas of perinatal epidemiology. In Study 1, we explored whether the association between short interpregnancy intervals (i.e., the end of one pregnancy to the start of the next) and increased risk of preterm birth may be due to residual confounding in three populations (n=693 American Indian and n=728 white women from the Northern Plains, U.S., and n=783 mixed ancestry women from the Western Cape, South Africa). Using data from the prospective Safe Passage cohort (2007-2015), we applied propensity score methods to control for a variety of sociodemographic and reproductive factors. A third-to-half of women with <6 months intervals had propensity scores that largely did not overlap with those of women with 18-23 months intervals. Since the propensity score models included factors related to both interpregnancy interval and preterm birth, these findings suggest the possibility of strong confounding in all three populations. The pooled associational estimate with preterm birth was attenuated in the propensity score trimmed and weighted data (risk ratio 1.4, 95% CI 0.75-2.6) compared with the crude results (risk ratio 1.7, 95% CI 1.1-2.7). However, the sample size and precision were reduced after propensity score trimming, and several covariates remained imbalanced. The data demonstrated the complexity of the processes leading to interpregnancy interval length. These issues may have been difficult to identify without comprehensive confounder data and with other methods, such as traditional regression adjustment. In Study 2, we examined the relative importance of timing (first trimester versus second/third trimesters) and degree of gestational weight gain in relation to infant size at birth (small-and-large-for-gestational age) among women with obesity using data from a medical records-based case-cohort study (Pittsburgh, PA, 1998-2010). We operationalized serial antenatal weight measurements as above, below, or within the current recommended ranges for U.S. pregnancies, i.e., 0.2-2.0 kg total gain in the first trimester and 0.17-0.27 kg per week in the second and third trimesters (based on group based trajectory modeling). Data were analyzed by obesity class (n=1290 in the class I subcohort, n=1247 class II, n=1198 class III). Our findings supported the current clinical guidelines, except for women with class III obesity. Among women with class III obesity, lower than recommended gain in the second and third trimesters was associated with decreased risk of having a large-for-gestational age infant (adjusted risk ratio 0.76, 95% CI 0.51-1.1), while not increasing small-for-gestational age (SGA) risk (adjusted risk ratio 1.0, 95% CI 0.63-1.7). Our results were in agreement with findings from several other studies of women with obesity using other methodologies to operationalize gestational weight gain. In Study 3, we used hierarchical clustering to explore latent groups of placental pathology features. We also investigated whether the placental clusters, in addition to birthweight percentiles, were beneficial to explain the variability of select adverse pregnancy outcomes. Data were from the Safe Passage Study (same as Study 1, n=2005). We identified one cluster with low prevalence of abnormalities (60.9%) and three clusters that mapped well to the expert consensus-based Amsterdam criteria: severe maternal vascular malperfusion (5.8%), fetal vascular malperfusion (11.1%), and inflammation (22.1%). The clusters were weakly-to-moderately associated with certain antenatal risk factors, pregnancy complications, and neonatal outcomes. Birthweight percentiles plus the placental clusters was better able to explain the variance of select adverse outcomes, compared with using small-for-gestational age only. This study serves as proof-of-concept that machine learning methods, and placental data, may aid in the identification and etiologic study of certain adverse pregnancy outcomes. In sum, all three studies support that the application of novel analytic methods to high-dimensional datasets may expand our understanding of certain causal questions, even ones that have been broached before, although, as seen in Study 2, such research may not always yield novel insights.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed Feb. 7, 2008). Includes bibliographical references.

As maternidades sucessivas na adolescência constituem uma situação complexa que requer da adolescente a administração de três dimensões, que inspiram cada uma delas, ponderações: o processo de adolescência, a maternidade e a criação de vários filhos, com o agravante de ocorrerem, em nosso país, em contexto de considerável desigualdade sócio-econômica. Tendo em vista tal problemática, foi desenvolvida a pesquisa em tela voltada à caracterização e análise dos contextos reprodutivos, sócioeconômicos e individuais de adolescentes com sucessivas maternidades no município de Rondonópolis-MT/Brasil. Foram selecionadas 49 participantes, usuárias do SUS, com idade entre 15 e 19 anos, com pelo menos um filho nascido vivo e que estavam novamente grávidas. Para a obtenção dos dados foi usado questionário sócio-econômico, entrevista aberta e entrevista semi-estruturada, após prévia aprovação pelo Comitê de Ética em Pesquisa da FSP-USP e a devida anuência das participantes de acordo com os termos do TCLE que lhes foi submetido. Outras informações foram obtidas por consultas aos Relatórios do Ministério da Saúde e bancos de dados SINASC e SISPRENATAL. Os dados foram organizados e analisados quanti-qualitativamente. Os dados quantitativos oriundos de fontes secundárias e do questionário aplicado foram organizados em tabelas de porcentagem. As espostas obtidas junto às adolescentes nas entrevistas e parte do questionário foram objeto de análise de conteúdo conforme os critérios classicamente aceitos. A dinâmica reprodutiva local mostrou-se consoante às tendências do país, tais como diminuição da porcentagem de gravidezes entre adolescentes, inclusive, entre aquelas com maternidades sucessivas. Entre as participantes, a primeira gravidez deu-se, em média, aos 15 anos e 2 meses, a segunda, aos 17 anos e 4 meses e a terceira aos 18 anos e 2 meses. Esse curto período pareceu expô-las às dificuldades cotidianas da criação dos filhos e as impediu de protagonizarem outros papéis sociais, como a de estudante e trabalhadora. Assim, se a primeira maternidade pode fornecer sentidos positivos para muitas das vivências das adolescentes e até mesmo colaborou para que construíssem uma identidade - ser mãe - e passassem a ocupar um lugar socialmente valorizado, as maternidades sucessivas pareceram ter contornos menos estruturantes, até mesmo,agravando as já precárias condições sócio-econômicas que as circundavam. Essa situação, pareceu igualmente ter impedido-lhes o acesso às ‘janelas de oportunidades’, principalmente, aquelas articuladas à escolarização. Concluiu-se que as ‘maternidades sucessivas na adolescência’ constituem-se, pelas suas conseqüências, num fenômeno diferente ao da ‘primeira gravidez na adolescência’. Enquanto essa se mostrou mais integrada às demandas da adolescente, as maternidades subseqüentes agravaram suas necessidades, multiplicando as situações adversas a elas associadas. / The consecutive motherhood in teenage women are a complex situation which requires from the teenager the administration of three dimensions and each one of them inspire careful considerations: the adolescence process, motherhood and the raising of several children in a context of considerable social-economical disparity. Having this type of problem in mind, the research was developed aiming to the characterization and analyzes of the reproductive, social-economical and individual contexts of teenagers who have had consecutive pregnancies in the county of Rondonópolis-MT/ Brazil. It was selected 49 participants, user of SUS with an age-rate from 15 to 19 years old, who have had, at least,one child that was born alive and were pregnant again. In order to obtain this socialeconomical data a questionnaire, an opened interview and a semi-structured interview were used after the Comitê de Ética em Pesquisa da FSP-USP’s approval and after the participants’ consent in agreement with the TCLE terms that were presented to them. Other informations were obtained by consulting the reports from the Department of Health (Ministério da Saúde) and the SINASC and SISPRENATAL data files. The data were organized and analyzed in terms of quantity and quality. The quantity data from secondary sources and from the questionnaire were organized in percentage charts. The answers obtained from the teenagers in the interviews and part of the questionnaire had its content analyzed in agreement with previously accepted criterions. The local reproductive dynamic presented itself consonant with the countries’ tendencies, such as the reduction of the percentage of pregnancies among teenage women including those with consecutive pregnancies. Among the participants, the first pregnancy took place at the age of 15 years and 02 months old (approximately), the second at the age of 17 years and 04 months old and the third pregnancy took place at the age of eighteen years and 02 months old. This short gap seemed to have exposed them to everyday difficulties in raising their children and kept them from playing other social roles such as the student and working professional. So, if the first pregnancy could provide positive experiences to the lives of these teenagers and even cooperate for the construction of an identity – to be a mother – and, by this, belong to a respectable and social space, the consecutive pregnancies seem to have less structural shapes, inclusively, by aggravating the difficult social-economical situations, that have already existed, surrounding these mothers. This situation equally seemed to have kept them away from the “window of opportunities”, especially those articulated with education. One concludes that the consecutive pregnancies in the adolescence, by its consequences, are a different phenomenon if compared to first pregnancy in the adolescence. While the last one seemed more integrated to the teenager’s demands, the consecutive pregnancies worsened their needs, multiplying associated adverse situations related to them.

As maternidades sucessivas na adolescência constituem uma situação complexa que requer da adolescente a administração de três dimensões, que inspiram cada uma delas, ponderações: o processo de adolescência, a maternidade e a criação de vários filhos, com o agravante de ocorrerem, em nosso país, em contexto de considerável desigualdade sócio-econômica. Tendo em vista tal problemática, foi desenvolvida a pesquisa em tela voltada à caracterização e análise dos contextos reprodutivos, sócioeconômicos e individuais de adolescentes com sucessivas maternidades no município de Rondonópolis-MT/Brasil. Foram selecionadas 49 participantes, usuárias do SUS, com idade entre 15 e 19 anos, com pelo menos um filho nascido vivo e que estavam novamente grávidas. Para a obtenção dos dados foi usado questionário sócio-econômico, entrevista aberta e entrevista semi-estruturada, após prévia aprovação pelo Comitê de Ética em Pesquisa da FSP-USP e a devida anuência das participantes de acordo com os termos do TCLE que lhes foi submetido. Outras informações foram obtidas por consultas aos Relatórios do Ministério da Saúde e bancos de dados SINASC e SISPRENATAL. Os dados foram organizados e analisados quanti-qualitativamente. Os dados quantitativos oriundos de fontes secundárias e do questionário aplicado foram organizados em tabelas de porcentagem. As espostas obtidas junto às adolescentes nas entrevistas e parte do questionário foram objeto de análise de conteúdo conforme os critérios classicamente aceitos. A dinâmica reprodutiva local mostrou-se consoante às tendências do país, tais como diminuição da porcentagem de gravidezes entre adolescentes, inclusive, entre aquelas com maternidades sucessivas. Entre as participantes, a primeira gravidez deu-se, em média, aos 15 anos e 2 meses, a segunda, aos 17 anos e 4 meses e a terceira aos 18 anos e 2 meses. Esse curto período pareceu expô-las às dificuldades cotidianas da criação dos filhos e as impediu de protagonizarem outros papéis sociais, como a de estudante e trabalhadora. Assim, se a primeira maternidade pode fornecer sentidos positivos para muitas das vivências das adolescentes e até mesmo colaborou para que construíssem uma identidade - ser mãe - e passassem a ocupar um lugar socialmente valorizado, as maternidades sucessivas pareceram ter contornos menos estruturantes, até mesmo,agravando as já precárias condições sócio-econômicas que as circundavam. Essa situação, pareceu igualmente ter impedido-lhes o acesso às ‘janelas de oportunidades’, principalmente, aquelas articuladas à escolarização. Concluiu-se que as ‘maternidades sucessivas na adolescência’ constituem-se, pelas suas conseqüências, num fenômeno diferente ao da ‘primeira gravidez na adolescência’. Enquanto essa se mostrou mais integrada às demandas da adolescente, as maternidades subseqüentes agravaram suas necessidades, multiplicando as situações adversas a elas associadas. / The consecutive motherhood in teenage women are a complex situation which requires from the teenager the administration of three dimensions and each one of them inspire careful considerations: the adolescence process, motherhood and the raising of several children in a context of considerable social-economical disparity. Having this type of problem in mind, the research was developed aiming to the characterization and analyzes of the reproductive, social-economical and individual contexts of teenagers who have had consecutive pregnancies in the county of Rondonópolis-MT/ Brazil. It was selected 49 participants, user of SUS with an age-rate from 15 to 19 years old, who have had, at least,one child that was born alive and were pregnant again. In order to obtain this socialeconomical data a questionnaire, an opened interview and a semi-structured interview were used after the Comitê de Ética em Pesquisa da FSP-USP’s approval and after the participants’ consent in agreement with the TCLE terms that were presented to them. Other informations were obtained by consulting the reports from the Department of Health (Ministério da Saúde) and the SINASC and SISPRENATAL data files. The data were organized and analyzed in terms of quantity and quality. The quantity data from secondary sources and from the questionnaire were organized in percentage charts. The answers obtained from the teenagers in the interviews and part of the questionnaire had its content analyzed in agreement with previously accepted criterions. The local reproductive dynamic presented itself consonant with the countries’ tendencies, such as the reduction of the percentage of pregnancies among teenage women including those with consecutive pregnancies. Among the participants, the first pregnancy took place at the age of 15 years and 02 months old (approximately), the second at the age of 17 years and 04 months old and the third pregnancy took place at the age of eighteen years and 02 months old. This short gap seemed to have exposed them to everyday difficulties in raising their children and kept them from playing other social roles such as the student and working professional. So, if the first pregnancy could provide positive experiences to the lives of these teenagers and even cooperate for the construction of an identity – to be a mother – and, by this, belong to a respectable and social space, the consecutive pregnancies seem to have less structural shapes, inclusively, by aggravating the difficult social-economical situations, that have already existed, surrounding these mothers. This situation equally seemed to have kept them away from the “window of opportunities", especially those articulated with education. One concludes that the consecutive pregnancies in the adolescence, by its consequences, are a different phenomenon if compared to first pregnancy in the adolescence. While the last one seemed more integrated to the teenager’s demands, the consecutive pregnancies worsened their needs, multiplying associated adverse situations related to them.

In this study, I describe the seasonality of reproduction in bottlenose dolphins by examining data from stranded animals, photographic surveys and focal follows. I examined inter-birth intervals from focal follows of known female dolphins. I found bottlenose dolphins that frequent the coastal waters of North Carolina to be comprised of at least two populations; one with a primarily spring birthing peak and a presumed second (or second and third) with two smaller birthing peaks in the fall and winter. These animals are reproducing at 2-3 year inter-birth intervals, which are shorter than bottlenose dolphin inter-birth intervals in the Moray Firth, Scotland, Shark Bay, Australia, or Sarasota Bay, FL. A decrease in reproductive intervals can indicate a density-dependent response to an anthropogenic disturbance or a natural change. Association patterns between and among these known females revealed relationships that have persisted for more than a decade. Most association patterns of the female dolphins in this area are long-term casual acquaintances which are evident in the fission-fusion grouping pattern, and individuals are not highly gregarious. Females appear to associate with most other females in the local area and do not form bands, as defined by researchers in Sarasota, FL (Wells et al. 1987). However, females do exhibit preferred associates, with whom they associate, regardless of reproductive state. Associations of females with young of the year were slightly stronger than associations between females with different aged calves, except for preferred associates. Future work will include genetic research on some of these known females, and continued study of the life and reproductive histories of these known females and their offspring. / Dissertation

Thesis (M.A. (Population and Reproductive Health Research))--Mahidol University, 1999.