Wildfire particulate exposure and risks of preterm birth and low birth weight in the Southwestern United States.

OBJECTIVES: Wildfire air pollution is a growing concern on human health. The study aims to assess the associations between wildfire air pollution and pregnancy outcomes in the Southwestern United States. STUDY DESIGN: This was a retrospective cohort study. METHODS: Birth records of 627,404 singleton deliveries in 2018 were obtained in eight states of the Southwestern United States and were linked to wildfire-sourced fine particulate matter (PM2.5) and their constituents (black carbon [BC] and organic carbon [OC]) during the entire gestational period. A double-robust logistic regression model was used to assess the associations of wildfire-sourced PM2.5 exposures and preterm birth and term low birth weight, adjusting for non-fire-sourced PM2.5 exposure and individual- and area-level confounder variables. RESULTS: Wildfire-sourced PM2.5 contributed on average 15% of the ambient total PM2.5 concentrations. For preterm birth, the strongest association was observed in the second trimester (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 1.05-1.07 for PM2.5; 1.06, 95% CI: 1.05-1.07 for BC; 1.04, 95% CI: 1.03-1.05 for OC, per interquartile range increment of exposure), with higher risks identified among non-smokers or those with low socio-economic status. For term low birth weight, the associations with wildfire-sourced PM2.5 exposures were consistently elevated for all trimesters except for the exposure averaged over the entire gestational period. Overall, the associations between wildfire-sourced PM2.5 and pregnancy outcomes were stronger than those with total PM2.5. CONCLUSIONS: Wildfire-sourced PM2.5 and its constituents are linked to higher risks of preterm birth and term low birth weight among a significant US population than the effects of ambient total PM2.5.

Spontaneous and indicated preterm delivery risk is increased among overweight and obese women without prepregnancy chronic disease.

OBJECTIVE: To investigate the independent impact of prepregnancy obesity on preterm delivery among women without chronic diseases by gestational age, preterm category and parity. DESIGN: A retrospective cohort study. SETTING: Data from the Consortium on Safe Labor (CSL) in the USA (2002-08). POPULATION: Singleton deliveries at ≥23 weeks of gestation in the CSL (43 200 nulliparas and 63 129 multiparas) with a prepregnancy body mass index (BMI) ≥18.5 kg/m2 and without chronic diseases. METHODS: Association of prepregnancy BMI and the risk of preterm delivery was examined using Poisson regression with normal weight as reference. MAIN OUTCOME MEASURES: Preterm deliveries were categorised by gestational age (extremely, very, moderate to late) and category (spontaneous, indicated, no recorded indication). RESULTS: Relative risk of spontaneous preterm delivery was increased for extremely preterm among obese nulliparas (1.26, 95% CI: 0.94-1.70 for overweight; 1.88, 95% CI: 1.30-2.71 for obese class I; 1.99, 95% CI: 1.32-3.01 for obese class II/III) and decreased for moderate to late preterm delivery among overweight and obese multiparas (0.90, 95% CI: 0.83-0.97 for overweight; 0.87, 95% CI: 0.78-0.97 for obese class I; 0.79, 95% CI: 0.69-0.90 for obese class II/III). Indicated preterm delivery risk was increased with prepregnancy BMI in a dose-response manner for extremely preterm and moderate to late preterm among nulliparas, as it was for moderate to late preterm delivery among multiparas. CONCLUSIONS: Prepregnancy BMI was associated with increased risk of preterm delivery even in the absence of chronic diseases, but the association was heterogeneous by preterm categories, gestational age and parity. TWEETABLE ABSTRACT: Obese nulliparas without chronic disease had higher risk for spontaneous delivery <28 weeks of gestation.

Comparison of methods for identifying small-for-gestational-age infants at risk of perinatal mortality among obese mothers: a hospital-based cohort study.

OBJECTIVE: To assess differences in small-for-gestational age (SGA) classifications for the detection of neonates with increased perinatal mortality risk among obese women and subsequently assess the association between prepregnancy body mass index (BMI) status and SGA. DESIGN: Hospital-based cohort. SETTING: Twelve US clinical centres (2002-08). POPULATION: A total of 114 626 singleton, nonanomalous pregnancies. METHODS: Data were collected using electronic medical record abstraction. Relative risks (RR) with 95% CI were estimated. MAIN OUTCOME MEASURES: SGA trends (birthweight < 10th centile) classified using population-based (SGAPOP ), intrauterine (SGAIU ) and customised (SGACUST ) references were assessed. The SGA-associated perinatal mortality risk was estimated among obese women. Using the SGA method most associated with perinatal mortality, the association between prepregnancy BMI and SGA was estimated. RESULTS: The overall perinatal mortality prevalence was 0.55% and this increased significantly with increasing BMI (P < 0.01). Among obese women, SGAIU detected the highest proportion of perinatal mortality cases (2.49%). Perinatal mortality was 5.32 times (95% CI 3.72-7.60) more likely among SGAIU neonates than non-SGAIU neonates. This is in comparison with the 3.71-fold (2.49-5.53) and 4.81-fold (3.41-6.80) increased risk observed when SGAPOP and SGACUST were used, respectively. Compared with women of normal weight, overweight women (RR = 0.82, 95% CI 0.78-0.86) and obese women (RR = 0.80; 95% CI 0.75-0.83) had a lower risk for delivering an SGAIU neonate. CONCLUSION: Among obese women, the intrauterine reference best identified neonates at risk of perinatal mortality. Based on SGAIU , SGA is less common among obese women but these SGA babies are at a high risk of death and remain an important group for surveillance. TWEETABLE ABSTRACT: SGA is less common among obese women but these SGA babies are at a high risk of death.

Differences in risk factors for incident and recurrent small-for-gestational-age birthweight: a hospital-based cohort study.

OBJECTIVE: Examine whether small-for-gestational-age (SGA) risk factors differed by prior SGA birth. DESIGN: Hospital-based cohort study. SETTING: Utah, USA. POPULATION: Electronic medical record data from 25,241 women who were nulliparous at study entry with ≥2 subsequent consecutive singleton deliveries (2002-2010). METHODS: Estimated adjusted relative risks (RR) and 95% confidence intervals (95% CI) for the association between second pregnancy characteristics and SGA risk. Tested for risk factor differences between recurrence and incidence (Pdifference). MAIN OUTCOME MEASURES: Second pregnancy incident (n = 1067) and recurrent SGA (n = 484) determined using a population-based reference. RESULTS: SGA complicated 20.3 and 4.5% of deliveries to women with and without a prior SGA birth, respectively. Young maternal age (Pdifference = 0.01) and pregnancy hypertensive diseases (Pdifference = 0.03) were associated with incident but not recurrent SGA. Significant risk factors for incidence and recurrence were smoking (incident RR = 1.64 [95% CI 1.22-2.19]; recurrent RR = 1.59 [95% CI 1.17-2.17]), short stature (incident RR = 1.34 [95% CI 1.16-1.54]; recurrent RR = 1.54 [95% CI 1.31-1.82]), prepregnancy underweight (incident RR = 1.32 [95% CI 1.07-1.64]; recurrent RR = 1.30 [95% CI 1.03-1.64]), and inadequate weight gain (incident RR = 1.41 [95% CI 1.22-1.64]; recurrent RR = 1.33 [95% CI 1.10-1.60]). Race-ethnicity, marital or insurance status, alcohol, diabetes, asthma, thyroid disease, depression, or interpregnancy interval were not associated with incidence or recurrence. CONCLUSION: There was considerable overlap in the risk factors for SGA recurrence and incidence. Recurrence and incidence risk factors included smoking, short stature, underweight, and inadequate weight gain. Maternal age and hypertensive diseases increased the risk for incidence only. Regardless of the SGA definition, some potentially modifiable risk factors for recurrence were identified.

The influence of sporadic anovulation on hormone levels in ovulatory cycles.

STUDY QUESTION: Do ovulatory hormone profiles among healthy premenopausal women differ between women with and without sporadic anovulation? SUMMARY ANSWER: Women with one anovulatory cycle tended to have lower estradiol, progesterone and LH peak levels during their ovulatory cycle. WHAT IS KNOWN ALREADY: Anovulation occurs sporadically in healthy premenopausal women, but the influence of hormones in a preceding cycle and the impact on a subsequent cycle's hormone levels is unknown. STUDY DESIGN, SIZE, DURATION: The BioCycle Study was a prospective cohort including 250 healthy regularly menstruating women, 18-44 years of age, from Western New York with no history of menstrual or ovulation disorders. The women were followed with up to eight study visits per cycle for two cycles, most of which were consecutive. PARTICIPANTS/MATERIALS, SETTING AND METHODS: All study visits were timed to menstrual cycle phase using fertility monitors and located at the University at Buffalo women's health research center from 2005 to 2007. The main outcomes measured were estradiol, progesterone, LH and follicle-stimulating hormone levels in serum at up to 16 visits over two cycles. Anovulation was defined as peak serum progesterone concentrations ≤5 ng/ml and no serum LH peak detected during the mid- or late-luteal phase visit. MAIN RESULTS AND THE ROLE OF CHANCE: Reproductive hormone concentrations were lower during anovulatory cycles, but significant reductions were also observed in estradiol (-25%, P = 0.003) and progesterone (-22%, P = 0.001) during the ovulatory cycles of women with one anovulatory cycle compared with women with two ovulatory cycles. LH peak concentrations were decreased in the ovulatory cycle of women with an anovulatory cycle (significant amplitude effect, P = 0.004; geometric mean levels 38% lower, P < 0.05). LIMITATIONS, REASONS FOR CAUTION: Follow-up was limited to two menstrual cycles, and no ultrasound assessment of ovulation was available. Data were missing for a total of 168 of a possible 4072 cycle visits (4.1%), though all women had at least five visits per cycle (94% had seven or more per cycle). WIDER IMPLICATIONS OF THE FINDINGS: These results suggest a possible underlying cause of anovulation, such as a longer-term subclinical follicular, ovarian or hypothalamic/pituitary dysfunction, even among healthy, regularly menstruating women.

Bone mineral density and blood metals in premenopausal women.

Exposure to metals, specifically cadmium, lead, and mercury, is widespread and is associated with reduced bone mineral density (BMD) in older populations, but the associations among premenopausal women are unclear. Therefore, we evaluated the relationship between these metals in blood and BMD (whole body, total hip, lumbar spine, and non-dominant wrist) quantified by dual energy X-ray absorptiometry in 248 premenopausal women, aged 18-44. Participants were of normal body mass index (mean BMI 24.1), young (mean age 27.4), 60% were white, 20% non-Hispanic black, 15% Asian, and 6% other race group, and were from the Buffalo, New York region. The median (interquartile range) level of cadmium was 0.30 µg/l (0.19-0.43), of lead was 0.86 µg/dl (0.68-1.20), and of mercury was 1.10 µg/l (0.58-2.00). BMD was treated both as a continuous variable in linear regression and dichotomized at the 10th percentile for logistic regression analyses. Mercury was associated with reduced odds of decreased lumbar spine BMD (0.66, 95% confidence interval: 0.44, 0.99), but overall, metals at environmentally relevant levels of exposure were not associated with reduced BMD in this population of healthy, reproductive-aged women. Further research is needed to determine if the blood levels of cadmium, lead, and mercury in this population are sufficiently low that there is no substantive impact on bone, or if effects on bone can be expected only at older ages.

Placental characteristics and risks of maternal mortality 50 years after delivery.

INTRODUCTION: Adverse pregnancy outcomes such as preterm delivery and preeclampsia are associated with a higher maternal risk for subsequent cardiovascular disease (CVD) and all-cause mortality. While such pregnancy conditions are related to abnormal placentation, little research has investigated whether pathologic placental measures could serve as a risk factor for future CVD mortality in mothers. METHODS: Longitudinal study of 33,336 women from the Collaborative Perinatal Project (CPP; 1959-1966) linked to mortality information through December 2016. Pathologists took extensive morphological and histopathological measures. Apart from assessing associations with morphological features, we derived an overall composite score and specific inflammation-related, hemorrhage-related, and hypoxia-related pathologic placenta index scores. Cox regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for mortality adjusting for covariates. RESULTS: Thirty-nine percent of women died with mean (standard deviation, SD) time to death of 39 (12) years. Mean (SD) placental weight and birthweight were 436 g (98) and 3156 g (566), respectively. Placenta-to-birthweight ratio was associated with all-cause mortality (adjusted HR 1.03: 1.01, 1.05 per SD in ratio). In cause-specific analyses, it was significantly associated with respiratory (HR 1.06), dementia (HR: 1.10) and liver (HR 1.04) related deaths. CVD, cancer, diabetes and kidney related deaths also tended to increase, whereas infection related deaths did not (HR 0.94; 0.83, 1.06). Placental measures of thickness, diameters, and histopathological measures grouped by inflammatory, hemorrhagic, or hypoxic etiology were not associated with mortality. DISCUSSION: Placental weight in relation to birthweight was associated with long-term maternal mortality but other histopathologic or morphologic features were not.

Urban-rural residence and the occurrence of neural tube defects in Texas, 1999-2003.

Neural tube birth defects (NTDs) affect more than 4000 pregnancies in the US annually. The etiology of NTDs is believed to be multifactorial, but much remains unknown. We examined the pattern and magnitude of urban-rural variation in anencephaly, spina bifida without anencephaly, and encephalocele in Texas in relation with urban-rural residence for the period 1999-2003. There was no evidence that urban-rural residence was associated with changes in the rate of anencephaly or spina bifida without anencephaly in unadjusted or adjusted analyses. In contrast, rates of encephalocele were statistically significantly higher in areas classified as suburban or more rural compared to urban areas using four different urban-rural residence indicators.

Pregnancy and perinatal health in Inner Mongolia, China, 1996-1999.

OBJECTIVE: To obtain descriptive measures of maternal and perinatal health in the Ba Men Region of Inner Mongolia, China. METHODS: Data collected from the Examination Chart for Pregnant Women for approximately 22,000 pregnancies in a three-county area of Inner Mongolia, China from December 1, 1996 through December 31, 1999 were analyzed for maternal, perinatal, and neonatal outcomes. RESULTS: Compared to selected developing countries, a higher percentage of women (99%) in this region received at least one prenatal care visit. This region was also characterized by a low percentage of low birthweight (<2.5 kg) infants (1%) and neonatal mortality rate (5 deaths per 1000 live births). CONCLUSIONS: Maternal and neonatal health outcomes in this region of Inner Mongolia were better than those in selected developing countries.

Maternal serum markers of lipid metabolism in relation to neonatal anthropometry.

OBJECTIVE: The objective of this study is to examine associations between lipids (high-density lipoprotein, low-density lipoprotein, total cholesterol, triglycerides and lipoprotein (a)) measured on average three time points during pregnancy and neonatal anthropometrics. STUDY DESIGN: Stored samples from a preeclampsia trial measured as part of a case-control study from five US centers (1992 to 1995) were used. The sample included women without pregnancy complications (n=136) and cases of gestational diabetes (n=93), abnormal glucose tolerance (AGT; n=76), gestational hypertension (n=170) and preeclampsia (n=177). Linear regression and linear mixed-effects models estimated adjusted associations between lipids and birth weight z-score, ponderal index (PI), length and head circumference. RESULTS: Among women without complications, cross-sectional associations between total cholesterol measured at different gestational ages increased PI 2.23 to 2.55 kg m-3 per-unit increase in cholesterol. HDL was inversely associated with birth length (ß's=-2.21 and -2.56 cm). For gestational hypertension, triglycerides were associated with birth weight z-score (ß's=0.24 to 0.31). For preeclampsia, HDL was associated with lower birth weight z-scores (ß's=-0.49 and -0.82). Women with gestational diabetes or AGT had inconsistent associations. Examining the level changes across pregnancy, each 0.0037 mmol l-1 increase in HDL was associated with decreased birth weight z-score (ß=-0.22), length (ß=-0.24 cm) and head circumference (ß=-0.24 cm), whereas each 0.028 mmol l-1 increase in triglycerides was associated with increased birth weight z-score (ß=0.13) and head circumference (ß=0.19 cm). CONCLUSIONS: Although associations varied by complications, in general, growth-promoting fuels such as total cholesterol and triglycerides were associated with increased neonatal size, whereas high HDL was associated with smaller size. Maternal HDL that failed to decrease over pregnancy was associated with smaller neonate size.

Environmental organochlorine exposure and postmenopausal breast cancer risk.

Environmental exposure to organochlorine compounds has been associated with a potential role in breast cancer etiology, but results from previous investigations yielded inconsistent results. In this case-control study, we examined the effect of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), hexachlorobenzene (HCB), mirex, and several measures of polychlorinated biphenyls (PCBs) on postmenopausal breast cancer risk. The study sample included 154 primary, incident, histologically confirmed, postmenopausal breast cancer cases and 192 postmenopausal community controls. Usual diet, reproductive and medical histories, and other lifestyle information was obtained by an extensive in person interview. Serum levels (ng/g) of DDE, HCB, mirex, and 73 PCB congeners were determined by gas chromatography with electron capture. PCB exposure was examined as total measured PCB levels, total number of detected PCB peaks, and three PCB congener groups. In the total sample, there was no evidence of an adverse effect of serum levels of DDE [odds ratio (OR), 1.34; 95% confidence interval (CI) 0.71-2.55], HCB (OR, 0.81; 95% CI, 0.43-1.53), or mirex (OR, 1.37; 95% CI, 0.78-2.39). Further, higher serum levels of total PCBs (OR, 1.14; 95% CI, 0.61-2.15), moderately chlorinated PCBs (OR, 1.37; 95% CI, 0.73-2.59), more highly chlorinated PCBs (OR, 1.19; 95% CI, 0.60-2.36), or greater number of detected peaks (OR, 1.34; 95% CI, 0.72-2.47) were not associated with increased risk. There was some indication of a modest increase in risk for women with detectable levels of less chlorinated PCBs (OR, 1.66; 95% CI, 1.07-2.88). Among parous women who had never lactated, there was some evidence for increased risk, associated with having detectable levels of mirex (OR, 2.42; 95% CI, 0.98-4.32), higher serum concentrations of total PCBs (OR, 2.87; 95% CI, 1.01-7.29), moderately chlorinated PCBs (OR, 3.57; 95% CI, 1.10-8.60), and greater numbers of detected PCB congeners (OR, 3.31; 95% CI, 1.04-11.3). These results suggest that an increase in risk of postmenopausal breast cancer associated with environmental exposure to PCBs and mirex, if at all present, is restricted to parous women who had never breast-fed an infant. Future studies should consider lactation history of participants, as well as use similar epidemiological and laboratory methodologies, to ensure comparability of results across studies.

Can regular multivitamin/mineral supplementation modify the relation between maternal smoking and select adverse birth outcomes?

PURPOSE: The purpose of this study was to examine whether or not regular multivitamin/mineral supplementation can modify the relation between maternal smoking and preterm birth (gestational age < 37 weeks), very-low-birthweight (VLBW) (< 1500 g), moderately-low-birthweight (MLBW) (< 2499 g), or small-for-gestational-age (SGA) (< 10th percentile of birth weight for gestational age). METHODS: Live birth data from the 1988 National Maternal and Infant Health Survey (NMIHS) were used for the analysis. Maternal smoking referred to self-reported average number of cigarettes smoked after recognition of pregnancy, while regular multivitamin/mineral supplementation referred to use of multivitamin/mineral supplements for at least three days per week during the three months before and/or after recognition of pregnancy. Sample sizes included 9402 singleton infants for the analysis of preterm birth, 9395 for very or moderately low birthweight, and 9363 for small-for-gestational-age. Odds ratios were derived from logistic regression analyses after adjusting for a number of demographic and reproductive variables. RESULTS: Major results include: 1) increased risks for the adverse outcomes studied were observed among smoking women; 2) no effect of regular multivitamin/mineral supplementation in the absence of maternal smoking was revealed; and 3) relative excess risks due to interaction at different smoking levels and overall interactions between smoking and supplementation were not observed. CONCLUSIONS: These results suggest that regular multivitamin/mineral supplementation does not minimize the adverse effects associated with maternal smoking.

Identifying critical windows of exposure for children's health.

Several authors have considered the importance of exposure timing and how this affects the outcomes observed, but no one has systematically compiled preconceptional, prenatal, and postnatal developmental exposures and subsequent outcomes. Efforts were undertaken to examine the information available and to evaluate implications for risk assessment for several areas: a) respiratory and immune systems, b) reproductive system, c) nervous system, d) cardiovascular system, endocrine system, and general growth, and e) cancer. Major conclusions from a workshop on "Critical Windows of Exposure for Children's Health" included a) broad windows of sensitivity can be identified for many systems but detailed information is limited; b) cross-species comparisons of dose to target tissue and better data on the exposure-dose-outcome continuum are needed; c) increased interaction among scientific disciplines can further understanding by using laboratory animal results in designing epidemiological studies and human data to suggest specific laboratory studies on mechanisms and agent-target interactions; and d) thus far, only limited attention has been given to peripubertal/adolescent exposures, adult consequences of developmental exposures, and genome-environment interactions. More specific information on developmental windows will improve risk assessment by identifying the most sensitive window(s) for evaluation of dose-response relationships and exposure, evaluation of biological plausibility of research findings in humans, and comparison of data across species. In public health and risk management, information on critical windows may help identify especially susceptible subgroups for specific interventions.

Consumption of PCB-contaminated sport fish and risk of spontaneous fetal death.

Spontaneous fetal death has been observed among various mammalian species after exposure to polychlorinated biphenyls (PCBs). Our exposure-based cohort study assessed the relationship between consumption of PCB-contaminated Lake Ontario sport fish and spontaneous fetal death using 1820 multigravid fertile women from the 1990-1991 New York State Angler Cohort Study. Fish consumption data were obtained from food frequency questionnaires and history of spontaneous fetal death from live birth certificates. Analyses were stratified by number of prior pregnancies and controlled for smoking and maternal age. No significant increases in risk for fetal death were observed across four measures of exposure: a lifetime estimate of PCB exposure based on species-specific PCB levels; the number of years of fish consumption; kilograms of sport fish consumed in 1990-1991; and a lifetime estimate of kilograms eaten. A slight risk reduction was seen for women with two prior pregnancies at the highest level of PCB exposure (odds ratio = 0.36; 95% CI, 0.14-0.92) and for women with three or more prior pregnancies with increasing years of fish consumption (odds ratio = 0.97; 95% CI, 0.94-0.99). These findings suggest that consumption of PCB-contaminated sport fish does not increase the risk of spontaneous fetal death.

Assessing exposure to disinfection by-products in women of reproductive age living in Corpus Christi, Texas, and Cobb county, Georgia: descriptive results and methods.

We conducted a field study in Corpus Christi, Texas, and Cobb County, Georgia, to evaluate exposure measures for disinfection by-products, with special emphasis on trihalomethanes (THMs). Participants were mothers living in either geographic area who had given birth to healthy infants from June 1998 through May 1999. We assessed exposure by sampling blood and water and obtaining information about water use habits and tap water characteristics. Two 10-mL whole blood samples were collected from each participant before and immediately after her shower. Levels of individual THM species (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) were measured in whole blood [parts per trillion (pptr)] and in water samples (parts per billion). In the Corpus Christi water samples, brominated compounds accounted for 71% of the total THM concentration by weight; in Cobb County, chloroform accounted for 88%. Significant differences in blood THM levels were observed between study locations. For example, the median baseline blood level of bromoform was 0.3 pptr and 3.5 pptr for participants in Cobb County and Corpus Christi, respectively (p = 0.0001). Differences were most striking in blood obtained after showering. For bromoform, the median blood levels were 0.5 pptr and 17 pptr for participants in Cobb County and Corpus Christi, respectively (p = 0.0001). These results suggest that blood levels of THM species vary substantially across populations, depending on both water quality characteristics and water use activities. Such variation has important implications for epidemiologic studies of the potential health effects of disinfection by-products.

Evaluation of a container for collection and shipment of semen with potential uses in population-based, clinical, and occupational settings.

Large, population-based studies of semen quality are encumbered by the logistics and expense of obtaining semen samples from men who live in a variety of locations. A prototype semen collection and transportation kit, the TRANSEM100, can be distributed to study participants and then directly shipped to a central laboratory for analysis. This study was designed to evaluate the ability of male volunteers to correctly use the kit. Thirty volunteers aged 20 to 44 years with no history of diabetes, recent chemotherapy, fertility problems, or vasectomy were recruited through a newspaper advertisement, interviewed to obtain demographic information, and instructed on the use of the kit. Twenty-six of the initial subjects provided at least 1 semen specimen using the kit and returned the specimens by overnight delivery to the laboratory for analysis, 25 completed a follow-up interview on the use of the collection kit, and 20 submitted a second semen sample using the same method. The average volunteer was white, 27.8 years old, and held at least a college degree. Forty percent of the volunteers were married. In general, participants correctly followed the instructions for collecting, packaging, and shipping the semen samples. Volunteers were instructed to collect samples after at least 2, but no more than 7 days of abstinence. For the first and second samples submitted, participants collected semen samples after an average of 3.3 and 3.9 days of abstinence, respectively. Seventeen (65%) of the samples from the first sampling period and 16 (80%) of the samples from the second period were received in the laboratory the day after they had been collected. In summary, the TRANSEM100 may prove to be useful for collecting human semen in field studies. Further testing of this method is warranted to evaluate preservation of sample quality and use of the kit by men among diverse socioeconomic groups.

Dental students' treatment of anxious patients.

Patients' anxiousness over treatment is an important factor in the utilization, delivery, and outcome of health care. Patient anxiety over dental treatment is widespread and is a source of stress for both patients and dentists. This paper reports a study of how dental students cope with fearful patients they treat during training, and what tactics they believe are effective. Two classes of senior dental students at a state university (n = 127) completed a brief questionnaire that asked them to describe what they had done in a previous encounter with a nervous patient, and to assess the effect of their actions. Students estimated that almost a quarter of their patients were anxious; most believed that they themselves were made nervous by such patients. Virtually all were committed to using talk plus local anesthesia rather than more extensive, drug-oriented methods. The coping repertoire was extensive. Giving reassurance was the most prominent tactic, followed by providing information about the procedure; expressing empathy or identifying patient feelings and the source of fear; and presenting a calm manner. Most students believed their actions had at least some positive, if not a dramatic, effect. In rating the effectiveness of 10 actions a dentist can take to deal with patient anxiety, the large majority of students rated every behavior as being at least somewhat effective. The behaviors rated 'very effective' by half or more of the students included having a calm manner, demonstrating that what the patient says is taken seriously, being friendly, making the patient feel welcome, and giving moral support during the procedure.

Comparative analysis of successful and unsuccessful candidates for the pediatric surgical matching program.

Only one third of the applicants for training in pediatric surgery obtain a position through the pediatric surgery matching program. In order to identify factors that contribute to a successful outcome, we conducted a retrospective survey of all participants in the matching process for positions during the years 1983 to 1991. This survey was designed to identify characteristics associated with success in the match through comparison of successful and unsuccessful applicants. Significant factors associated with a successful match included: a greater incidence of residency-supported research (P = .012) with a greater number of publications (P = .003) and national presentations (P = .014), specifically at the annual meetings of the American Pediatric Surgical Association (P = .05) and the American Academy of Pediatrics (P = .05). In addition, successful candidates had more contact with (P = .004) and letters of recommendation from (P = .015) well-known pediatric surgeons involved in the general surgical residency program. This information should be invaluable to those counseling medical students and residents interested in a career in pediatric surgery.

The dentist-patient relationship: perceived dentist behaviors that reduce patient anxiety and increase satisfaction.

This study relates perceived dentist behaviors to anxiety reduction in patients during treatment, and to satisfaction with the dental visit. The sample consisted of 250 adult patients, 110 men and 140 women, at two outpatient hospital dental clinics. Immediately after treatment, patients were asked to respond to a list of 25 dentist behaviors thought to be associated with positive dentist-patient interaction. Criterion measures obtained by patients were self-ratings of anxiety during treatment and satisfaction measures from the DVSS. Ten behaviors were significantly associated with anxiety reduction. A stepwise multiple regression analysis with anxiety reduction as the dependent variable indicated that to the patient, the dentist's explicit dedication to prevent pain was the most important dentist behavior, with friendliness, working quickly, being calm, and giving moral support, being important auxiliary behaviors. Most of the 25 dentist behaviors studied were associated with patient satisfaction. A stepwise multiple regression analysis indicated that the dentist's empathy and communicativeness were among important correlates of patient satisfaction. An experimental approach to causal analysis of anxiety reducing behaviors needs to be studied.

Infecundity and consumption of polychlorinated biphenyl-contaminated fish.

Biologic capacity for reproduction, or fecundity, may be threatened by environmental contaminants, especially compounds capable of disrupting endocrine pathways. Telephone interviews that focused on reproductive events were conducted with female members of the New York State Angler Cohort Study who became pregnant between 1991 and 1993 and who reported known time to pregnancy (N = 895; 73%). Consumption of polychlorinated biphenyl-contaminated Lake Ontario sportfish and other factors were ascertained in 1991. The authors classified the women as follows: (a) fecund (time to pregnancy < or =12 cycles; n = 723); (b) having resolved infecundity (time to pregnancy > 12 cycles; n = 81); or (c) having unresolved infecundity (time to pregnancy > 12 cycles without pregnancy; n = 94). Adjusted odds ratios for duration of fish consumption for both resolved and unresolved infecundity were elevated (1.46 and 1.19, respectively), although confidence intervals included unity. Frequency of recent fish consumption was associated with an increased risk for select categories, although confidence intervals included one.