Biomedical subjects

Deshayne B Fell

Publications and source records attributed to Deshayne B Fell.

8 recordsLinked to original sources

PubMed2006

Stillbirth risk factors according to timing of exposure.

PURPOSE: The purpose of the present study is to identify risk factors for stillbirth and explore hypotheses about the cause of stillbirth based on the time in gestation when exposures occur. METHODS: Relationships between lifestyle factors, pregnancy conditions, medication use, and occupation on risk for stillbirth were examined within a population-based case-control study. Women who had a stillbirth and a random sample of women who had a live birth between 1999 and 2001 were identified through perinatal databases in Nova Scotia and Eastern Ontario, Canada. Exposure data were collected for each month of pregnancy and analyzed within trimesters. Case-control data were converted to case-cohort data, and hazard ratios (HRs) and 95% confidence intervals (CIs) were determined from Cox proportional hazards models. RESULTS: This study included 105 stillbirth cases and 389 live-birth controls. Fertility treatment in the present pregnancy was associated with increased risk for stillbirth (adjusted HR, 4.0; 95% CI, 1.4-11.6). Smoking during the first trimester also was associated with increased risk for stillbirth (adjusted HR, 2.4; 95% CI, 1.2-4.9). Other risk factors included antiemetic use during the first trimester, second-trimester antibiotic use, low family income, and age older than 35 years. CONCLUSIONS: Risk factors identified in this study concur with findings of previous studies and support the importance of early pregnancy exposures on stillbirth risk.

Adult↗

PubMed2006

Risk factors for hyperemesis gravidarum requiring hospital admission during pregnancy.

OBJECTIVE: To identify risk factors for hyperemesis requiring hospital admission during pregnancy. METHODS: Data from a population-based cohort of all deliveries in Nova Scotia, Canada between 1988 and 2002 were obtained from the Nova Scotia Atlee Perinatal Database. Women with 1 or more antepartum admissions for hyperemesis were compared with women with no admissions for hyperemesis. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated using logistic regression and used to determine a set of independent risk factors for hyperemesis. RESULTS: The overall rate of admission for hyperemesis was 0.8% (n = 1,301) among 157,922 deliveries. In the adjusted analysis, hyperthyroid disorders (RR 4.5, 95% CI 1.8-11.1), psychiatric illness (RR 4.1, 95% CI 3.0-5.7), previous molar pregnancy (RR 3.3, 95% CI 1.6-6.8), preexisting diabetes (RR 2.6, 95% CI 1.5-4.7), gastrointestinal disorders (RR 2.5, 95% CI 1.8-3.6), and asthma (RR 1.5, 95% CI 1.2-1.9) were all statistically significant risk factors for hyperemesis, whereas maternal smoking and maternal age older than 30 were associated with decreased risk. Compared with singleton male pregnancies, singleton female pregnancies, pregnancies with multiple male fetuses, and male and female combinations were associated with statistically significant increased risk of hyperemesis. CONCLUSION: Although hospitalization for hyperemesis occurs in less than 1% of pregnant women, this translates to a large number of hospital admissions. The factors associated with hyperemesis are primarily medical and fetal factors that are not easily modifiable, but identification of these factors may be useful in determining those women at high risk for developing hyperemesis. LEVEL OF EVIDENCE: II-2.

Adult↗

PubMed2006

Outcomes of pregnancies complicated by hyperemesis gravidarum.

OBJECTIVE: To evaluate maternal and neonatal outcomes among women with hyperemesis during pregnancy. METHODS: A population-based retrospective cohort study was conducted among women with singleton deliveries between 1988 and 2002. Hyperemetic pregnancies were defined as those requiring one or more antepartum admissions for hyperemesis before 24 weeks of gestation. Severity of hyperemesis was evaluated according to the number of antenatal hospital admissions (1 or 2 versus 3 or more) and according to weight gain during pregnancy (< 7 kg [15.4 lb] versus > or = 7 kg). Maternal outcomes evaluated included weight gain during pregnancy, gestational diabetes, gestational hypertension, labor induction, and cesarean delivery. Neonatal outcomes included 5-minute Apgar score of less than 7, low birth weight, small for gestational age, preterm delivery, and perinatal death. Logistic regression was used to generate adjusted odds ratios for all outcomes, and the odds ratios were converted to relative risks. RESULTS: Of the 156,091 singleton pregnancies, 1,270 had an admission for hyperemesis. Compared to women without hyperemesis, infants born to women with hyperemesis and with low pregnancy weight gain (< 7 kg [15.4 lb]) were more likely to be low birth weight, small for gestational age (SGA), born before 37 weeks of gestation, and have a 5-minute Apgar score of less than 7. Compared with infants born to women without hyperemesis, rates of low birth weight and preterm delivery were substantially higher among infants born to women with hyperemesis and low pregnancy weight gain (4.2% versus 12.5% and 4.9% versus 13.9%, respectively). The outcomes among infants born to women with hyperemesis with pregnancy weight gain of 7 kg (15.4 lb) or more were not different from the outcomes among women without hyperemesis. CONCLUSION: The results of this study suggest that the adverse infant outcomes associated with hyperemesis are a consequence of, and mostly limited to, women with poor maternal weight gain. LEVEL OF EVIDENCE: II-2.

Adult↗

PubMed2006

Influence of a new province-wide trauma system on motor vehicle trauma care and mortality.

BACKGROUND: Mature trauma systems have evolved to respond to high rates of major injury morbidity and mortality. Characterized by prehospital care, triage, transportation, aggressive resuscitation, surgery, and rehabilitation, trauma systems have been found to improve survival for seriously injured patients. In Nova Scotia, a province-wide trauma system was implemented between 1995 and 1998. This study investigated the influence of the province-wide trauma system on motor vehicle trauma care and mortality in its first 2 years of existence. METHODS: Subjects over the age of 15 years were identified using E-codes pertaining to motor vehicle traffic crashes from population-based hospital claims and vital statistics data. Individuals who were hospitalized or died because of a motor vehicle crash in 1993 through 1994, before trauma system implementation, were compared with those who were hospitalized or died in 1999 through 2000, after the trauma system was implemented. RESULTS: In the 2-year period after trauma system implementation, there was a 21% increase in the number of seriously injured individuals with a primary admission to tertiary care. This increase was both clinically and statistically significant even after adjustment for age, gender, multiple injuries, head injury, municipality of residence, and vital status at discharge (RR, 1.21, 95% CI, 1.05-1.35). There was no evidence that the probability of dying while in hospital significantly changed in the first 2 years after trauma system implementation. INTERPRETATION: These results indicate that individuals seriously injured in motor vehicle crashes in Nova Scotia are more likely to be admitted to tertiary care in the postimplementation period.

Accidents, Traffic↗

PubMed2004

Exposure assessment in epidemiologic studies of adverse pregnancy outcomes and disinfection byproducts.

A major challenge in studies that examine the association between disinfection byproducts in drinking water and pregnancy outcomes is the accurate representation of a subject's exposure. We used household water samples and questionnaire information on water-use behavior to examine several aspects of exposure assessment: (i) the distribution and correlation of specific disinfection byproducts, (ii) spatial distribution system and temporal variation in byproduct levels, and (iii) the contribution of individual water-use behavior. The level of specific trihalomethanes (THMs) and haloacetic acids (HAAs) was determined for 360 household water samples in Eastern Ontario and Nova Scotia. Subjects were interviewed regarding tap water ingestion and showering and bathing practices. In both provinces, total THMs correlated highly with chloroform (correlation coefficient (r) >0.95) and less so with total HAAs (r = 0.74 in Nova Scotia and r = 0.52 in Ontario). The correlation between total THMs and bromodichloromethane was high in Nova Scotia (r = 0.63), but low in Ontario (r = 0.26). The correlation was between THM level in individual household samples, and the mean THM level during the same time period from several distribution system samples was 0.63, while a higher correlation in THM level was observed for samples taken at the same location 1 year apart (r = 0.87). A correlation of 0.73 was found between household THM level and a total exposure measure incorporating ingestion, showering, and bathing behaviors. These results point to the importance of: measurement of different classes of byproducts; household rather than distribution system sampling; and, incorporation of subject behaviors in exposure assessment in epidemiologic studies of disinfection byproducts and adverse pregnancy outcomes.

Acetates↗

PubMed2004

Trihalomethanes in public water supplies and risk of stillbirth.

BACKGROUND: The chlorine used to disinfect public drinking water supplies reacts with naturally occurring organic matter to form a number of chemical byproducts. Recent studies have implicated exposure to chlorination byproducts in drinking water, trihalomethanes (THMs), in particular, with intrauterine death. METHODS: We conducted a population-based case-control study in Nova Scotia and Eastern Ontario, Canada, to examine the effect of exposure to THMs on stillbirth risk. Cases were women who had a stillborn infant, and controls were a random sample of women with live births. Subjects were interviewed, and women with a public water source provided a residential water sample. Risks were examined according to residential THM level in tap water and to a total exposure metric incorporating tap water ingestion, showering, and bathing. RESULTS: We enrolled 112 stillbirth cases and 398 live birth controls. Women with a residential total THM level of 80 or more microg/L had twice the risk of a stillbirth compared with women with no exposure to THMs (adjusted odds ratio [OR] = 2.2; 95% confidence interval [CI] = 1.1-4.4). The highest quintile of total THM exposure using the total exposure metric was associated with an adjusted odds ratio of 2.4 (95% CI = 1.2-4.6) compared with women not exposed to THMs. Similar results were seen for specific THM compounds. A monotonic dose-response relationship was not seen. CONCLUSIONS: Our results provide evidence for an increased risk of stillbirth associated with exposure to chlorination byproducts through ingestion and showering and bathing, although there was not a clear dose-response relationship.

Adult↗

PubMed2004

Residential mobility during pregnancy.

In epidemiological studies of environmental exposures and adverse pregnancy outcomes, maternal residence at delivery is often used to assign an exposure level, based on routinely collected data. In order to examine the potential for exposure misclassification due to residential mobility, we examined maternal mobility according to changes in residence overall, as well as changes in municipality and county. The potential for mobility to be related to pregnancy outcomes was considered by examining the relationship between mobility and risk factors commonly included in investigations of adverse pregnancy outcomes. Previously collected data were studied from 398 population-based control subjects from a case-control study of stillbirths. We compared demographic, lifestyle, medical, pregnancy and environmental factors of women who moved during pregnancy with those who did not. Bivariable and multivariable log binomial regressions were used to identify risk factors that were associated with mobility during pregnancy. Twelve per cent of subjects moved at least once during their pregnancy. Among women who moved, the majority (62%) moved within the same municipality. In bivariable analyses, we found that low family income, lower maternal age, unmarried status and tobacco use were associated with an increased likelihood of moving during pregnancy, whereas women who used folic acid before conception and who had a higher prepregnancy body mass index (BMI) were less likely to move during pregnancy. In multivariable analyses, only family income, age and prepregnancy BMI were independently predictive of mobility. These results indicate that in studies using maternal residence at delivery to assign environmental exposures, mobility during pregnancy is likely to be prevalent enough to introduce exposure misclassification. The potential for differential exposure misclassification should be considered should any of the risk factors for moving identified by this study also be risk factors for the outcome under study.

Adult↗

PubMedDate not supplied

Changes in maternal characteristics in Nova Scotia, Canada from 1988 to 2001.

BACKGROUND: Maternal characteristics such as age, parity, smoking status, pre-pregnancy weight and pregnancy weight gain have changed in many industrialized countries in recent years. Many of these changes have not been adequately described at a population level. The purpose of this study was to describe recent trends in selected maternal characteristics in Nova Scotia. METHODS: Data from a population-based perinatal database were used to examine changes in maternal age, parity, smoking, pre-pregnancy weight, delivery weight and pregnancy weight gain among all deliveries between 1988 and 2001. RESULTS: The proportion of deliveries to women > or = 35 years increased by 84% over the study period from 7.0% in 1988-1991 to 12.9% in 1998-2000, while deliveries to women > or = 40 years increased by more than 100%. The number of nulliparous women > or = 35 years also increased significantly. The overall prevalence of smoking decreased from 32.7% in 1988-1991 to 25.1% in 1998-2001, however the prevalence of smoking among women <20 years did not change over the study period and was almost 50%. The proportion of women with a pre-pregnancy weight of > or = 90 kilograms (kg) increased by 165% from 4.1% in 1988-1991 to 10.7% in 1998-2001. The proportion of women with pregnancy weight gain of < 7 kg and > or =18 kg increased by 37% and 13%, respectively. CONCLUSION: Dramatic changes have occurred in several important maternal characteristics and there is evidence of ongoing change. Continuation of these trends is likely to impact on future obstetric practice and perinatal health.

Adult↗