The problem. Group B Streptococci (GBS) are one of the most frequent causes of life-threatening infections in newly born infants, who acquire the micro-organism while passing through the genital tracts of their asymptomatic colonized mothers. Some previous studies have suggested that maternal genital colonization by GBS is associated with preterm rupture of the fetal membranes and preterm delivery. In this thesis both a prevalence study and a historical cohort study were conducted, to investigate the prevalence of maternal GBS colonization at 28 weeks of gestation, and whether there is an association between colonization and preterm rupture of the fetal membranes. Background information. Different rates for maternal GBS colonization during pregnancy have been reported, ranging from 4.6% up to 40%. The association between maternal GBS colonization and preterm rupture of the membranes has been reported in some studies, but other studies have not supported this view, which led to differsnces in opinions and the lack of a specific conclusion. The variations in the findings of these studies may have been due to several factors, which include differences in cultured sites and phase of pregnancy at which culture was obtained, in addition to the wide variations in the definition of premature rupture of the membranes used by various authors. (Abstract shortened by UMI.)

Long term preventive hormone replacement therapy (LTP-HRT) is attracting considerable attention for its potential in reducing the incidence of coronary heart disease and osteoporosis associated fractures in post-menopausal women. The study objectives were: (1) to describe women's decisions and decisional conflict regarding LTP-HRT after being presented with the evidence of benefits and risks and clarifying values; (2) to describe the difference between those who accept or decline LTP-HRT in terms of: (a) expectations of LTP-HRT benefits and risks, and (b) the importance women attach to the benefits and the risks; and (3) to describe the factors women identify as contributing to their decision to take or not take LTP-HRT or being unsure about taking LTP-HRT. The typical woman who participated in the study was 57 years of age; had some post secondary education; and was currently using HRT. Over half the women had at least one CHD risk factor and had a hysterectomy. Less than 15% of the respondents reported having osteoporosis or a first degree relative with breast cancer. Women's decisions to take LTP-HRT were distributed as follows: 56% yes; 26% no; and 18% unsure. Women who accepted or declined LTP-HRT did not have statistically significant differences in expectations of risk of CHD, osteoporosis, and breast cancer with and without hormone therapy. In contrast, women's importance ratings of LTP-HRT benefits and side effects did differ significantly between those accepting and declining LTP-HRT. The reasons most often identified by women who chose LTP-HRT were prevention of CHD and osteoporosis (61%) and relief of hot flashes (54%). Those who chose not to take LTP-HRT gave reasons such as dislike of taking pills (47%), and risk of cancer (11%). (Abstract shortened by UMI.)

The development and release of clinical practice guidelines continue unabated. Yet the question remains: do practice guidelines guide practitioners? This study examines the implementation of guidelines published by Canada's National Advisory Committee on Immunization (NACI) on hepatitis B screening in pregnancy. Hepatitis B is transmitted to infants from their chronic carrier mothers during the perinatal period. Asymptomatic HBsAg positive mothers are at risk of transmitting their infection to their newborns at a rate of 20 to 30%. Mothers who are also HBeAg positive transmit the infection at a rate of 70-90%. Ninety percent of infants infected in the perinatal period will become chronic carriers. Such infants have an increased risk for chronic active hepatitis, cirrhosis and hepatocellular carcinoma. Twenty-five percent will die of chronic liver disease in early adulthood. The use of hepatitis B immune globulin and vaccine after birth can prevent up to 90% of hepatitis B infections in infants. Successful immunoprophylaxis of an infant requires that her carrier mother be identified prior to giving birth. In 1989, after years of recommending screening on a selective high risk basis, NACI recommended screening all pregnant women for hepatitis B surface antigen (HBsAg). If testing was not done during pregnancy it was to be done at the time of delivery.

Incidence of cancer of the corpus uteri (of which 89% is endometrial adenocarcinoma) in Canada is declining in women under 70 years of age; in women 70 and over incidence increased from 1969 until 1982 since when it has been stable. These incidence data use as a denominator all women in the population, rather than just women with intact uteri, who constitute the real population at risk. A descriptive analysis was done using data from national databases on incidence, mortality, morphology, method of diagnosis, surgical procedures and population numbers, focussing on incidence in women $\ge$70 years of age. A variety of models for the hysterectomy adjustment all resulted in a trend of increasing incidence in women over 70 years of age; this effect is most important in the most recent period, where the adjustment changes stable crude rates into increasing adjusted ones. Decreasing proportions of diagnosis by death certificate only, and decreasing mortality/incidence ratios in recent periods suggest some improvement in diagnosis in elderly women. Incidence of cancer of the corpus uteri, adjusted for hysterectomy prevalence, is increasing in women over 70 years of age in Canada. There is a cohort effect which may represent residual increased risk from unopposed estrogen use in the 1970s. There is also some (weak) evidence to suggest improved diagnosis of this cancer in elderly women in recent periods. Absolute numbers of cases in women $\ge$70 years are definitely increasing as the population ages. (Abstract shortened by UMI.)

Low birthweight of newborns is a major determinant of perinatal survival as well as postnatal morbidity. It represents major public health problem and is of great economic concern in developing countries. This study investigated the impact of four groups of risk factors: genetic and constitutional factors, namely infant sex, ethnic origin, maternal height and maternal pre-pregnancy weight; demographic/psychosocial and nutritional factors related to the mother, namely maternal age prior to pregnancy, maternal education, occupation, total family income, total gestational weight gain, use of iron and/ or vitamin supplements and haemoglobin level; obstetric factors such as parity, interpregnancy interval, gestational age of previous birth, prior spontaneous abortion, prior stillbirth, prior child death and period of gestation at delivery; and antenatal care (i.e number of antenatal care visits). To identify and quantify risk factors for low birthweight I conducted a hospital-based case-control study at the Kuala Lumpur Maternity Hospital, Malaysia. The case-control study of 295 low birthweights and 590 controls showed that Indian ethnic origin, previous premature birth, low maternal pre-pregnancy weight (46-50 kg), brief use of iron and/or vitamin supplements (2-4 weeks) and prematurity were significant independent risk factors for low birthweight. The results of this study showed that low maternal pre-pregnancy weight, premature birth, poor quality of antenatal care are important and potentially modifiable risk factors. Hence the results suggest that nutritional and health intervention programmes (i.e improvement in nutritional status and antenatal care) can reduce the incidence of low birthweight.

Trichomonas vaginalis is a protozoan parasite that causes a common sexually transmitted disease, trichomoniasis. Despite its high prevalance, the pathogenesis and immunogenicity of T. vaginalis are not well understood. Because currently available therapies are not always effective in treatment or in disease control and because of the impact of T. vaginalis on the health of women, a vaccination strategy could be an effective method of prevention. We studied the protective effects of subcutaneous immunization with T. vaginalis using a mouse model of vaginal infection. Balb/c mice were either immunized with T. vaginalis suspended in Freund's complete adjuvant (FCA) at day $-$56 and boosted with Freund's incomplete adjuvant (FIA) at day $-$28, or immunized only at day $-$28 with either Tv/FCA or Tv/FIA. Control mice were sham immunized and boosted with phosphate-buffered saline suspended in FCA and FIA respectively. At day 0 all mice were intravaginally inoculated with T. vaginalis. Mice immunized and boosted had significantly less intravaginal infection and had an elevated serum and vaginal antibody response compared to single immunization or control mice. Immunization with whole T.vaginalis appears to confer protection against intravaginal challenge with T. vaginalis in this animal model of infection.

A secondary analysis of data from a sample of pregnant smokers is described, which focuses on examining knowledge, attitudes and beliefs related to women's decision to continue smoking during pregnancy. Pregnant women are examined at each of the first three stages of change: women not considering quitting in the next six months (Precontemplation), women considering cessation in this time frame (Contemplation), and women planning on stopping smoking in the next 30 days (Preparation). Pregnant women (n = 2461) were surveyed in a cross-sectional convenience sample of prenatal clinic attendees in a city of approximately 350,000 people, over a one-year period. 32% of pregnant smokers were in the Precontemplation stage, 35% in Contemplation, and 33% in Preparation. In general, participants' level of knowledge was high about maternal and fetal risks of smoking during pregnancy. However, similar items assessing personal perceptions of risk showed that many women thought their personal risk was lower than pregnant smokers in general. Negative affect was the dominant motive, and Level 1 reasons (doubting the evidence of harm) were cited as being most important factors related to continued smoking. Overall, participants gave higher ratings to the cons of smoking than to the pros. Women in Preparation had significantly higher knowledge of risks from smoking during pregnancy than Contemplators, but did not differ significantly from Precontemplators, while Precontemplators did not differ significantly from Contemplators on this variable. Women in Preparation had a significantly higher personal perception of risk for the fetus of smoking during pregnancy than women in the other two stages. As expected, Precontemplators perceived significantly lower Cons of smoking than women in the other two stages, who did not differ significantly from each other. (Abstract shortened by UMI.)

A growing body of literature suggests that healthy and well-nourished women can safely participate in most forms of physical activity during pregnancy. In addition, participation in physical activity during pregnancy may have potential health benefits, such as reducing the risk of gestational diabetes mellitus. These potential benefits are reflected in a recent opinion issued by the American College of Obstetricians and Gynecologists (ACOG), in which women without medical or obstetric complications are recommended to accumulate 30 minutes or more of moderate intensity physical activity on most, if not all, days of the week. Despite these recommendations, little is known concerning current patterns of physical activity among pregnant women. The first study of this dissertation addressed this limitation by providing estimates of the frequency, intensity, and duration of commonly performed activities during pregnancy among a racially and economically diverse sample of women receiving prenatal care. Comprehensive 24-hour recalls were used to measure physical activity in all activity domains and the factors associated with activity were identified. The second study in this dissertation evaluated the reliability and validity of the Kaiser Physical Activity Survey (KPAS) when used to assess pregnancy physical activity. The KPAS assesses all domains of physical activity and is more practical than 24-hour recalls to measure activity in large epidemiologic studies. These results suggest that the KPAS is a reliable and reasonably accurate instrument for estimating physical activity among pregnant women. These findings should help to address the need for valid instruments to assess pregnancy physical activity in etiologic research, as most prior studies have focused on leisure time activity using questionnaires not validated for use among pregnant women. The final study in this dissertation used the KPAS to examine the association between physical activity during pregnancy and gestational weight gain among Hispanic women. This study was unique in its use of a measure of total activity energy expenditure, rather than a measure of leisure exercise, as the exposure of interest. Consistent with prior literature, moderate levels of physical activity was not efficacious in preventing excess weight gain during pregnancy.

This research generated theory related to women's self-treatment of vaginal symptoms utilizing the grounded theory method. Data collection guided by theoretical sampling consisted of interviews with women and pharmacists, consumer literature related to vaginal conditions, and advertisements for non-prescription vaginal antifungal products. Data analysis identified that the basic problem experienced by the women was relief of symptoms. Because of many competing demands on their personal time, the women needed to resolve their problem in a way that was uncomplicated and involved minimal use of time and resources. In order to accomplish this, women used the process of Bypassing the Middleman. The use of this process enabled women to resolve the problem in a convenient and timely manner, and provided the least disruption to their current lifestyles and beliefs. Bypassing the middleman consisted of four stages: Noticing Vaginal Symptoms, Making Sense of Symptoms, Choosing a Treatment Path, and Bypassing the Middleman. The pace and progression through the stages is influenced by each women's unique attributes and circumstances. Several conditions that facilitated this process were low degree of uncertainty about cause of symptoms and low need to know specific cause, judgment that the symptoms were low-risk and minor, feeling capable of solving the problem, perception that the time and effort to access the middleman (health care provider) were beyond her resources, a high priority for convenience, the belief that self-treatment (non-drug) was safer than medical treatment, and low congruence of beliefs between woman and health care provider. Analysis of advertisements and consumer literature provided the context for understanding environmental influences on women's knowledge and decision-making about self-treatment. Four principal factors emerged as the primary reasons for variance in participants' behavior during bypassing the middleman: symptom characteristics, available resources, knowledge and experience, and beliefs about symptom management. This theory contributes to nursing knowledge about women's self-care because it is grounded in data, and provides nurses with the ability to explain and predict which women will choose to use this process. In addition, this theory identifies controllable conditions for designing nursing interventions to enhance women's self-care skills.

This study explored whether prenatal attachment differed in women who conceived through IVF with their own eggs versus those who conceived with donor eggs and whether source of eggs, number of treatment cycles, anxiety and social support in pregnancy were predictive of prenatal attachment in this population of women. Three study designs were used: (1) a comparative descriptive design to compare prenatal attachment in women who used their own eggs and those who used donor eggs, (2) a predictive correlational design to identify significant predictors of prenatal attachment, and (3) a descriptive correlational design to examine the relationships between selected demographic variables and prenatal attachment. The admission sample consisted of 113 women who conceived through in vitro fertilization and completed an on-line survey. Of these women, 102 conceived with their own eggs and 11 with donor eggs. Their mean age was 34 years, and they were predominantly Caucasian, married, and well educated. Participation in the study was announced through a posting on the bulletin boards of two web sites related to pregnancy after infertility. An on-line survey was used to collect data on sociodemographic information, source of eggs, number of treatment cycles, anxiety (State-Trait Anxiety Inventory), social support in pregnancy (Social Support Apgar), and prenatal attachment (Maternal-Fetal Attachment Scale). No significant differences were found in prenatal attachment between women who conceived with their own eggs and women who conceived with donor eggs. Source of eggs, number of treatment cycles, anxiety and social support in pregnancy were not significant predictors of prenatal attachment for the study sample. Women who conceived with their own eggs had significantly less trait anxiety and higher social support. Prenatal attachment was positively and significantly correlated with fetal movement, known sex of baby, and anxiety. Influences on prenatal attachment in women conceiving through IVF are multifaceted and much is still unknown. Uncovering influencing variables and better understanding the process of developing prenatal attachment in women conceiving through IVF will provide nurses the evidence base they need to practice and support these women through pregnancy and beyond. Implications of this study and directions for further research are discussed.