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David A Savitz

Publications and source records attributed to David A Savitz.

At least 73 records · Page 4Linked to original sources
PubMed2003

Bacterial vaginosis, vaginal fluid neutrophil defensins, and preterm birth.

OBJECTIVE: To examine the association between bacterial vaginosis, vaginal fluid neutrophil defensins, and preterm birth. METHODS: Vaginal fluid specimens were obtained at 24-29 weeks' gestation from 242 cases with preterm birth and 507 noncases sampled using a case-cohort study design. We tested for bacterial vaginosis by Gram staining and Nugent scores and assayed for neutrophil defensins by enzyme-linked immunosorbent assay. Bacterial vaginosis was studied as a categoric variable (negative, intermediate, and positive), whereas defensins were studied as a continuous, categoric (based on percentiles), and dichotomous measure (presence versus absence). Three gestational age cut points were used to define preterm birth. Modified Cox proportional hazard models were used to evaluate the associations between bacterial vaginosis, defensins, and degree (less than 32, less than 34, and less than 37 weeks) and type (premature rupture of membranes, preterm labor) of preterm birth. RESULTS: Elevated vaginal fluid neutrophil defensins were not associated with birth before 37 weeks. Compared with women who did not have measurable vaginal fluid defensins, women with higher defensin levels (0-2.8 micro g/mL, 2.8-8.2 micro g/mL, and greater than 8.2 micro g/mL) had a greater risk of delivering before 32 weeks. Hazard ratios adjusted for maternal race and vaginal bleeding during pregnancy and 95% confidence intervals for these defensin levels were 1.7 (0.4, 6.9), 2.4 (0.7, 7.9), and 3.1 (1.0, 9.8), respectively. Bacterial vaginosis status did not influence the association between defensins and preterm birth. CONCLUSION: Elevated concentrations of vaginal fluid neutrophil defensins at 24-29 weeks' gestation might predict preterm birth before 32 weeks.

Adult↗
PubMed2003

Modeling community-level effects on preterm birth.

PURPOSE: We demonstrate modeling of community-level socioeconomic influences on risk of preterm birth (< 37 weeks gestation) in the Pregnancy, Infection, and Nutrition (PIN) Study. METHODS: Community-level information from the US Census was linked to 930 White and 817 African-American (Black) participants from a prospective cohort in central North Carolina through geocoded addresses, providing 123 census tracts with community-level and individual-level data for multi-level statistical analyses. RESULTS: Preterm delivery was experienced by 12.1% of Black and 10.4% of White participants. No appreciable aggregation of risk by community was discernable for White women. For Black women, random-coefficient logistic regression tract-specific preterm prevalence estimates ranged from 10.1% to 14.5%, "shrunk" from observed prevalences of 0% to 100%. Adding tract-level variables to the model representing median splits for household income and percent of single women heads of households with dependents, adjusting for individual-level maternal age and household income, accounted for much of the remaining between-tracts variation. CONCLUSIONS: Residing in a wealthier tract (> $30,000/year median income) was associated with reduced risk for Black women, adjusted OR = 0.59 (95% CI: 0.36, 0.96). The estimated conditional effect of lower community prevalence of female headed households was OR = 0.71 (95% CI: 0.43, 1.17).

Adolescent↗
PubMed2003

Accuracy of reporting of sexual activity during late pregnancy.

Women recalled their sexual activity during pregnancy in telephone interviews occurring during and after the third trimester, as part of a study of preterm delivery in central North Carolina in 1996-97. This retrospective information was compared with prospective daily records for the same time periods in a subsample of 88 women. Relative to the daily records, women reported fewer episodes of intercourse and longer intervals since the most recent orgasm when they recalled this information in interviews. Recall of sexual activity over short, recent time periods during pregnancy appears to be a source of some misclassification. Reliance on retrospective reports may suffice for general measures of objective events, such as any vs. no intercourse over a short time period.

Adolescent↗
PubMed2003

Vitamin C intake and the risk of preterm delivery.

OBJECTIVE: Ascorbic acid deficiency may lead to premature rupture of the membranes. STUDY DESIGN: The study included a prospective cohort of pregnant women, aged >/=16 years, with singleton gestations who received care at one of four prenatal clinics in central North Carolina from 1995 through 1998. Vitamin C intake preconceptionally and during the second trimester was examined for its association with preterm delivery and subsets of preterm labor, premature rupture of the membranes, and medical induction in 2064 women. RESULTS: Women who had total vitamin C intakes of <10th percentile preconceptionally had twice the risk of preterm delivery because of premature rupture of the membranes (relative risk, 2.2; 95% CI, 1.1, 4.5). This risk was attenuated slightly for second-trimester intake (relative risk, 1.7; 95% CI, 0.8, 3.5). The elevated risk of preterm premature rupture of the membranes was greatest for women with a low vitamin C intake during both time periods. CONCLUSION: Because diet and supplement use are modifiable behaviors, corroboration of these findings would suggest a possible intervention strategy.

Adolescent↗
PubMed2003

Epidemiologic evidence on the carcinogenicity of metalworking fluids.

The purpose of this review is to organize and evaluate the epidemiologic evidence regarding the potential carcinogenicity of metalworking fluids. Published literature was initially examined to identify the key contributions, with a strong emphasis on the series of studies by Eisen et al. A key challenge to addressing the issue is the diversity of metalworking fluids, additives, and by-products produced in use, along with the notable changes in the composition and use of such agents over time. Although several smaller cohort studies provided useful data on this issue through the 1980s, the Eisen et al. studies offer unique information given the size of the cohort, sophistication in exposure assessment, and detailed analysis of cancer mortality risks within the cohort as a function of estimated exposure. The most notable associations, based on precision, magnitude, and evidence for increasing risk with increasing exposure are those between straight metalworking fluids and both rectal and laryngeal cancer, as well as soluble metalworking fluids and laryngeal cancer. Further progress will require additional studies of the scale of Eisen et al.'s as well as a more systematic approach to integrating information from toxicology and industrial hygiene into the interpretation of the epidemiologic literature.

Carcinogenicity Tests↗
PubMed2003

The association between impaired glucose tolerance and birth weight among black and white women in central North Carolina.

OBJECTIVE: This study examines the relationship of glucose intolerance during pregnancy to birth weight among black and white participants of the Pregnancy, Infection, and Nutrition Study. RESEARCH DESIGN AND METHODS: This prospective cohort study recruited women from prenatal clinics in central North Carolina at 24-29 weeks' gestation. A 1-h 50-g glucose challenge test (GCT) and 100-g oral glucose tolerance test (OGTT) were conducted. Impaired glucose tolerance (IGT) was defined as one high value on the OGTT, gestational diabetes mellitus (GDM) as two or more high values, and normal glucose tolerance (NGT) was defined as a low or high value on the GCT screen but no high values on the OGTT. Women with known glucose status and birth outcome information were included in this analysis (n = 2055). RESULTS: Black women with IGT had higher rates of both macrosomia (38.5%) and large for gestational age (LGA) (53.9%) compared with white women (10.0% and 13.2%). Black infants' birth weights (3800 g) and prevalence of macrosomia and LGA were significantly higher among mothers with IGT compared with NGT women (birth weight, 3184 g; macrosomia, 7.0%; LGA, 11.6%). In contrast, among white infants, there was no significant increase in birth weight, macrosomia, or LGA associated with the mother's glucose tolerance status. In addition, there was no effect of GDM on birth weight in either group. CONCLUSIONS: This study suggests that, independent of maternal prepregnant weight, there may be significant increased risk of macrosomia among black IGT women but not among white IGT women. Further investigations into factors that may contribute to the observed results are needed.

Adult↗
PubMed2002

Occupational exposure to crystalline silica and risk of systemic lupus erythematosus: a population-based, case-control study in the southeastern United States.

OBJECTIVE: Crystalline silica may act as an immune adjuvant to increase inflammation and antibody production, and findings of occupational cohort studies suggest that silica exposure may be a risk factor for systemic lupus erythematosus (SLE). We undertook this population-based study to examine the association between occupational silica exposure and SLE in the southeastern US. METHODS: SLE patients (n = 265; diagnosed between January 1, 1995 and July 31, 1999) were recruited from 4 university rheumatology practices and 30 community-based rheumatologists in 60 contiguous counties. Controls (n = 355), frequency-matched to patients by age, sex, and state of residence, were randomly selected from driver's license registries. The mean age of the patients at diagnosis was 39 years; 91% were women and 60% were African American. Detailed occupational and farming histories were collected by in-person interviews. Silica exposure was determined through blinded assessment of job histories by 3 industrial hygienists, and potential medium- or high-level exposures were confirmed through followup telephone interviews. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression. RESULTS: More patients (19%) than controls (8%) had a history of medium- or high-level silica exposure from farming or trades. We observed an association between silica and SLE (medium exposure OR 2.1 [95% CI 1.1-4.0], high exposure OR 4.6 [95% CI 1.4-15.4]) that was seen in separate analyses by sex, race, and at different levels of education. CONCLUSION: These results suggest that crystalline silica exposure may promote the development of SLE in some individuals. Additional research is recommended in other populations, using study designs that minimize potential selection bias and maximize the quality of exposure assessment.

Adolescent↗
PubMed2002

Indicators of cocaine exposure and preterm birth.

OBJECTIVE: To identify predictors of cocaine exposure during pregnancy, using hair and urine assays and self-report, and the association with preterm birth. METHODS: A nested case-control study was conducted in a cohort of 2611 black and white women enrolled in prenatal care in central North Carolina. Cocaine exposure was ascertained by self-report (263 cases, 612 controls), urine assays at 24-29 weeks' gestation (226 cases, 564 controls) and postpartum (160 cases, 408 controls), and postpartum hair assays (169 cases, 435 controls). The major metabolite of cocaine, benzoylecgonine, was measured in urine. Cocaine and benzoylecgonine were measured in hair. RESULTS: Cocaine exposure was identified in 2% based on self-report, 5-6% based on urine assays, and 13-15% based on hair assays. Black ethnicity, lower education, and poverty were strongly predictive of positive hair assays. Hair cocaine and benzoylecgonine were not associated with preterm birth, with the possible exception of higher levels of cocaine and benzoylecgonine and birth before 34 weeks' completed gestation. The urine screen at 24-29 weeks' gestation also gave some indication of a possible association (odds ratio 1.7, 95% confidence interval 0.9, 3.5). CONCLUSION: The study corroborates the incompleteness of cocaine exposure assessment by self-report and urine screens relative to hair assays. The strong demographic predictors of exposure suggest where intervention efforts should be targeted. The most sensitive markers of exposure, hair cocaine and benzoylecgonine, are not associated with preterm birth, perhaps because they reflect different patterns of cocaine exposure than the other measures.

Case-Control Studies↗
PubMed2002

Risk score for antenatal bacterial vaginosis: BV PIN points.

OBJECTIVE: Develop a clinical risk score to screen for antenatal bacterial vaginosis (BV), irrespective of symptoms. STUDY DESIGN: Cohort study of 913 pregnant women with last menstrual periods between January 30, 1995 and February 22, 1997. BV was evaluated by Nugent-scored vaginal smears (scores of 7 to 10 considered positive) between 24 and 29 weeks' gestation. Forty-four potential risk factors were assessed. RESULTS: 17.8% of women had BV, of whom 22% were screened for BV by the usual care provider. Logistic regression-adjusted analyses found six predictors: vaginal pH>4.5 (OR=11.6, 95% confidence interval [CI] [7.8, 17.2]); black race (OR=1.9, 95% CI [1.3, 2.8]); condom use during pregnancy (OR=1.6, 95% CI [1.0, 2.5]); antenatal BV (OR=1.7, 95% CI [1.0, 2.8]); absence of sperm on smear (OR=1.7, 95% CI [1.0, 2.9]); and no history of sexually transmitted diseases (OR=1.6, 95% CI [1.0, 2.5]). Risk score weights were 5 for an elevated vaginal pH and 1 otherwise. The sensitivity and specificity of screening women with scores > or =4 were both 77%; this would involve screening 33% of patients. CONCLUSION: Approximately 80% of our BV cases were asymptomatic, emphasizing the need for objective risk assessment. Using six factors, clinicians can identify pregnant women at risk for BV.

Adolescent↗
PubMed2002

What are pregnant women eating? Nutrient and food group differences by race.

OBJECTIVE: The purpose of this study was to identify foods that contributed most to nutrient and fiber intake in a sample of pregnant women in North Carolina. STUDY DESIGN: This was a prospective study of women in the Pregnancy, Infection, and Nutrition Study (n = 2247 women). Dietary information during the second trimester was collected with the use of a food frequency questionnaire. The contribution of each food item to the population's intake was calculated. RESULTS: Overall, low nutrient-dense foods were major contributors to energy, fat, and carbohydrates, whereas fortified foods were important sources of iron, folate, and vitamin C. The median energy intake for this population was 2478 kcal. The median dietary intakes of iron were below the recommended levels. Although black women consumed more calories on average, white women, after energy adjustment, consumed greater amounts of protein, iron, folate, and fiber. CONCLUSION: These data emphasize the importance of evaluating both the nutrient density in the diet and the frequency of consumption in the assessment of the diets of pregnant women.

Black or African American↗
PubMed2002

Bacterial vaginosis and vaginal fluid defensins during pregnancy.

OBJECTIVE: The purpose of this study was to examine the association between Gram stain findings of vaginal fluid and the concentration of vaginal fluid neutrophil defensins. STUDY DESIGN: Vaginal fluid specimens obtained from 749 women at 24 to 29 weeks of gestation were tested for bacterial vaginosis and assayed for neutrophil defensins. Bacterial vaginosis was studied as a categoric variable (negative, intermediate, and positive), whereas defensins were examined as a continuous measure and dichotomized on the basis of presence versus absence and at the 90th percentile. Multiple linear and logistic regression models were used to assess the relationship between bacterial vaginosis and defensins. RESULTS: Women with intermediate bacterial vaginosis were more likely to have elevated vaginal fluid neutrophil defensins (>90th percentile) than women with normal vaginal flora (adjusted odds ratio, 2.3; 95% CI, 1.3, 4.2), whereas women with frank bacterial vaginosis were not (adjusted odds ratio, 1.3; 95% CI, 0.7, 2.6). Among women with any detectable defensin (69.5% of the study population), intermediate bacterial vaginosis was associated positively with defensin concentrations in multiple linear regression models (P =.007). Women with intermediate and frank bacterial vaginosis had 5.9 microg/mL and 2.2 microg/mL higher defensin concentrations, respectively, than women who did not have bacterial vaginosis. The presence of leukocytes in vaginal fluids was associated positively with defensin concentrations (P <.0001). CONCLUSION: Changes in vaginal microflora during mid pregnancy are associated with an increased concentration of vaginal fluid neutrophil defensins.

Adolescent↗
PubMed2002

Comparison of pregnancy dating by last menstrual period, ultrasound scanning, and their combination.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of algorithms for the assignment of gestational age with the use of the last menstrual period and early ultrasound information. STUDY DESIGN: Gestational age estimates that are based on last menstrual period, ultrasound scanning, or their combination were compared among women who attended prenatal care clinics in central North Carolina (n = 3655) by an evaluation of digit preference in the last menstrual period dates and a comparison of mean gestational age, preterm and postterm categories with the use of kappa statistics, difference between actual and expected delivery date, and birth weight among subgroups with discrepant assignments. RESULTS: Last menstrual period reports show digit preference, assign gestation 2.8 days longer on average than ultrasound scanning, yield substantially more postterm births (12.1% vs 3.4%), and predict delivery among term births less accurately. Misclassification of births as postterm was more common in younger women, those of nonoptimal prepregnancy body weight, cigarette smokers, and women who reported last menstrual period using preferred dates of the month. CONCLUSION: Last menstrual period estimates of the duration of gestation are subject to both random error and a systematic tendency to overstate the duration of gestation, most likely because of delayed ovulation.

Adolescent↗
PubMed2002

Vigorous leisure activity and pregnancy outcome.

BACKGROUND: Preterm birth is the leading cause of perinatal mortality in North America and Europe and a major predictor of neonatal and infant morbidity. Postterm birth is associated with increased infant mortality and morbidity, as well as increased frequency of surgical or induced labor. Because vigorous leisure activity may affect timing of delivery, this study examined association between vigorous leisure activity and birth outcomes. METHODS: Women (N = 1,699) with a singleton pregnancy were recruited at 24-29 weeks' gestation from prenatal clinics in central North Carolina between 1995 and 1998. The type and duration of any regular vigorous leisure activity was assessed in a telephone interview covering the 3-month period before pregnancy and during the first and second trimesters of pregnancy. RESULTS: The prevalence of vigorous leisure activity was 22% before pregnancy, 14% during the first trimester, and 8% during the second trimester. Vigorous leisure activity before pregnancy was unrelated to preterm (<37 weeks) as compared with term delivery (37 to <42 weeks). The risk of preterm birth was somewhat reduced with vigorous leisure activity during the first trimester (odds ratio = 0.80; 95% confidence interval = 0.48-1.35) and more so during the second trimester (odds ratio = 0.52; 95% confidence interval = 0.24-1.11). Vigorous leisure activity before pregnancy or during the first or second trimester was not associated with postterm delivery (>/=42 weeks). CONCLUSIONS: Vigorous leisure activity during the first trimester, and even more so in the second trimester, was associated with a reduced risk of preterm birth. There was no association with postterm birth. To address the etiologic role of activity on pregnancy outcome and to overcome self-selection, a randomized clinical trial would be needed.

Female↗
PubMed2002

Organochlorine exposure and age at natural menopause.

BACKGROUND: The effect of potential endocrine-modulating organochlorines on menopause has not been extensively examined. METHODS: We evaluated the associations of plasma polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis( -chlorophenyl)ethylene (DDE) with age at natural menopause. We analyzed data from 1407 women in a population-based, case-control study of breast cancer that was carried out in 1993-1996 in North Carolina. RESULTS: The adjusted hazard ratio estimating the rate of onset of natural menopause was 1.4 (95% confidence interval = 0.9-2.1) for the top decile of DDE compared with values below the median. This association is similar in magnitude to the association between smoking and menopause (hazard ratio = 1.4 [1.1-1.9]). No association was seen with PCBs. CONCLUSIONS: The suggested effect of DDE on timing of natural menopause encourages further research to corroborate these findings and evaluate potential mechanisms. Prospective studies, in which exposure measurements are taken before menopause, would be particularly useful.

Adult↗
PubMed2002

Steroid hormone levels during pregnancy and incidence of maternal breast cancer.

Previous studies evaluating pregnancy hormone levels and maternal breast cancer were limited to surrogate indicators of exposure. This study directly evaluates the association between measured serum steroid hormone levels during pregnancy and maternal risk of breast cancer. A nested case-control study was conducted to examine third-trimester serum levels of total unconjugated estradiol, estrone, estriol, and progesterone in women who were pregnant between 1959 and 1966. Cases (n = 194) were diagnosed with in situ or invasive breast cancer between 1969 and 1991. Controls (n = 374) were matched to cases by age at the time of index pregnancy, using randomized recruitment. Elevated progesterone levels were associated with a decreased incidence of breast cancer [odds ratio (OR) for progesterone > or =270 ng/ml, 0.49; 95% confidence interval (CI), 0.22-1.1] relative to those below the lowest decile. This association was stronger for cancers diagnosed at or before age 50 (OR for progesterone > or =270 ng/ml, 0.3; 95% CI, 0.1-0.9). Increased estrone levels were associated with an increased incidence overall (OR for estrone > or =18.7 ng/ml, 2.5; 95% CI, 1.0-6.2), whereas a positive association with estradiol was not observed. Too few cases occurred within 15 years of the index pregnancy to compare adequately the short- and long-term effects of pregnancy hormone exposure. When estrogen-to-progesterone ratios were evaluated, there was an indication of a modest increased incidence of breast cancer for those with high total estrogens and high estrone levels relative to progesterone. These findings suggest that pregnancy steroid hormone levels are risk factors for breast cancer.

Adolescent↗