Prenatal phthalate exposure and performance on the Neonatal Behavioral Assessment Scale in a multiethnic birth cohort

We investigated the relationship between prenatal maternal urinary concentrations of phthalate metabolites and neonatal behavior in their 295 children enrolled in a multiethnic birth cohort between 1998 and 2002 at the Mount Sinai School of Medicine in New York City. Trained examiners administered the Brazelton Neonatal Behavioral Assessment Scale (BNBAS) to children within 5 days of delivery. We measured metabolites of 7 phthalate esters in maternal urine that was collected between 25 and 40 weeks' gestation. All but two phthalate metabolites were over 95% detectable. We summed metabolites on a molar basis into low and high molecular weight phthalates. We hypothesized the existence of sex-specific effects from phthalate exposure a priori given the hormonal activity of these chemicals. Overall we found few associations between individual phthalate metabolites or their molar sums and most of the BNBAS domains. However, we observed significant sex-phthalate metabolite interactions (p<0.10) for the Orientation and Motor domains and the overall Quality of Alertness score. Among girls, there was a significant linear decline in adjusted mean Orientation score with increasing urinary concentrations of high molecular weight phthalate metabolites (B=-0.37, p=0.02). Likewise, there was a strong linear decline in their adjusted mean Quality of Alertness score (B=-0.48, p<0.01). In addition, boys and girls demonstrated opposite patterns of association between low and high molecular weight phthalate metabolite concentrations and motor performance, with some indication of improved motor performance with increasing concentration of low molecular weight phthalate metabolites among boys. This is the first study to report an association between prenatal phthalate exposure and neurological effects in humans or animals, and as such requires replication.

Prenatal phenol and phthalate exposures and birth outcomes

BACKGROUND

Many phthalates and phenols are hormonally active and are suspected to alter the course of development.

OBJECTIVE

We investigated prenatal exposures to phthalate and phenol metabolites and their associations with body size measures of the infants at birth.

METHODS

We measured 5 phenol and 10 phthalate urinary metabolites in a multiethnic cohort of 404 women in New York City during their third trimester of pregnancy and recorded size of infants at birth.

RESULTS

Median urinary concentrations were > 10 microg/L for 2 of 5 phenols and 6 of 10 phthalate monoester metabolites. Concentrations of low-molecular-weight phthalate monoesters (low-MWP) were approximately 5-fold greater than those of high-molecular-weight metabolites. Low-MWP metabolites had a positive association with gestational age [0.97 day gestational age per ln-biomarker; 95% confidence interval (CI), 0.07-1.9 days, multivariate adjusted] and with head circumference. Higher prenatal exposures to 2,5-dichlorophenol (2,5-DCP) predicted lower birth weight in boys (-210 g average birth weight difference between the third tertile and first tertile of 2,5-DCP; 95% CI, 71-348 g). Higher maternal benzophenone-3 (BP3) concentrations were associated with a similar decrease in birth weight among girls but with greater birth weight in boys.

CONCLUSIONS

We observed a range of phthalate and phenol exposures during pregnancy in our population, but few were associated with birth size. The association of 2,5-DCP and BP3 with reduced or increased birth weight could be important in very early or small-size births. In addition, positive associations of urinary metabolites with some outcomes may be attributable partly to unresolved confounding with maternal anthropometric factors.

Prenatal organophosphate metabolite and organochlorine levels and performance on the Brazelton Neonatal Behavioral Assessment Scale in a multiethnic pregnancy cohort

Prenatal exposures to organophosphate pesticides and polychlorinated biphenyls have been associated with abnormal neonatal behavior and/or primitive reflexes. In 1998-2002, the Mount Sinai Children's Environmental Health Center (New York City) investigated the effects of indoor pesticide use and exposure to polychlorinated biphenyls on pregnancy outcome and child neurodevelopment in an inner-city multiethnic cohort. The Brazelton Neonatal Behavioral Assessment Scale was administered before hospital discharge (n = 311). Maternal urine samples were analyzed for six dialkylphosphate metabolites and malathion dicarboxylic acid. A random subset of maternal peripheral blood samples from the entire cohort (n = 194) was analyzed for polychlorinated biphenyls and 1,1'-dichloro-2,2'-bis(4-chlorophenyl)ethylene. Malathion dicarboxylic acid levels above the limit of detection were associated with a 2.24-fold increase in the number of abnormal reflexes (95% confidence interval: 1.55, 3.24). Likewise, higher levels of total diethylphosphates and total dialkylphosphates were associated with an increase in abnormal reflexes, as was total dimethylphosphates after paraoxonase expression was considered. No adverse associations were found with polychlorinated biphenyl or 1,1'-dichloro-2,2'-bis(4-chlorophenyl)ethylene levels and any behavior. The authors uncovered additional evidence that prenatal levels of organophosphate pesticide metabolites are associated with anomalies in primitive reflexes, which are a critical marker of neurologic integrity.

Methodologic and logistic issues in conducting longitudinal birth cohort studies: lessons learned from the Centers for Children's Environmental Health and Disease Prevention Research

In anticipation of the National Children's Study, lessons can be learned from the smaller birth cohort studies conducted by five Centers for Children's Environmental Health and Disease Prevention Research funded by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency. The populations studied are diverse in ethnicity and social class and reside in urban and rural environments. Although almost all of the centers chose to enroll participants through medical care facilities, they had to develop independent staffs and structures because of the overburdened medical care system. Some of the lessons learned by the centers include the importance of continuous funding, building community partnerships to conduct culturally appropriate research, hiring bilingual and bicultural staff from the community, prioritizing research goals, developing biorepositories to ensure future utility of samples, instituting quality control procedures for all aspects of specimen and data collection, maintaining frequent contact with study participants, ensuring ethical conduct of the research in a changing medical-legal climate, and communicating results in a timely and appropriate manner to participants and the wider community. All centers underestimated the necessary start-up time, staff, and costs in conducting these birth cohort studies. Despite the logistical complexity and added expenses, all centers emphasize the importance of studying the impact of environmental exposures on those children most at risk, those living in minority and low-income communities. These centers present barriers encountered, solutions found, and considerations for future research, with the hope that the lessons learned can help inform the planning and conduct of the National Children's Study.

Psychological trauma associated with the World Trade Center attacks and its effect on pregnancy outcome

The destruction of the World Trade Center (WTC) on 11 September 2001 was a source of enormous psychological trauma that may have consequences for the health of pregnant women and their fetuses. In this report, we describe the impact of extreme trauma on the birth outcomes of women highly exposed to the WTC. We enrolled 187 women who were pregnant and living or working within close proximity to the WTC on 11 September. Among women with singleton pregnancies, 52 completed at least one psychological assessment prior to delivery. In adjusted multivariable models, both post-traumatic stress symptomatology (PTSS) and moderate depression were associated with longer gestational durations, although only PTSS was associated with decrements in infant head circumference at birth (beta=-0.07, SE=0.03, P=0.01). The impact of stress resulting from extreme trauma may be different from that which results from ordinary life experiences, particularly with respect to cortisol production. As prenatal PTSS was associated with decrements in head circumference, this may influence subsequent neurocognitive development. Long-term follow-up of infants exposed to extreme trauma in utero is needed to evaluate the persistence of these effects.

Transgenerational effects of posttraumatic stress disorder in babies of mothers exposed to the World Trade Center attacks during pregnancy

CONTEXT

Reduced cortisol levels have been linked with vulnerability to posttraumatic stress disorder (PTSD) and the risk factor of parental PTSD in adult offspring of Holocaust survivors.

OBJECTIVE

The purpose of this study was to report on the relationship between maternal PTSD symptoms and salivary cortisol levels in infants of mothers directly exposed to the World Trade Center collapse on September 11, 2001 during pregnancy.

DESIGN

Mothers (n = 38) collected salivary cortisol samples from themselves and their 1-yr-old babies at awakening and at bedtime.

RESULTS

Lower cortisol levels were observed in both mothers (F = 5.15, df = 1, 34; P = 0.030) and babies of mothers (F = 8.0, df = 1, 29; P = 0.008) who developed PTSD in response to September 11 compared with mothers who did not develop PTSD and their babies. Lower cortisol levels were most apparent in babies born to mothers with PTSD exposed in their third trimesters.

CONCLUSIONS

The data suggest that effects of maternal PTSD related to cortisol can be observed very early in the life of the offspring and underscore the relevance of in utero contributors to putative biological risk for PTSD.

Exposures among pregnant women near the World Trade Center site on 11 September 2001

We have characterized environmental exposures among 187 women who were pregnant, were at or near the World Trade Center (WTC) on or soon after 11 September 2001, and are enrolled in a prospective cohort study of health effects. Exposures were assessed by estimating time spent in five zones around the WTC and by developing an exposure index (EI) based on plume reconstruction modeling. The daily reconstructed dust levels were correlated with levels of particulate matter < or = 2.5 microm in aerodynamic diameter (PM2.5; r = 0.68) or PM10 (r = 0.73-0.93) reported from 26 September through 8 October 2001 at four of six sites near the WTC whose data we examined. Biomarkers were measured in a subset. Most (71%) of these women were located within eight blocks of the WTC at 0900 hr on 11 September, and 12 women were in one of the two WTC towers. Daily EIs were determined to be highest immediately after 11 September and became much lower but remained highly variable over the next 4 weeks. The weekly summary EI was associated strongly with women's perception of air quality from week 2 to week 4 after the collapse (p < 0.0001). The highest levels of polycyclic aromatic hydrocarbon-deoxyribonucleic acid (PAH-DNA) adducts were seen among women whose blood was collected sooner after 11 September, but levels showed no significant associations with EI or other potential WTC exposure sources. Lead and cobalt in urine were weakly correlated with sigmaEI, but not among samples collected closest to 11 September. Plasma OC levels were low. The median polychlorinated biphenyl level (sum of congeners 118, 138, 153, 180) was 84 ng/g lipid and had a nonsignificant positive association with sigmaEI (p > 0.05). 1,2,3,4,6,7,8-Heptachlorodibenzodioxin levels (median, 30 pg/g lipid) were similar to levels reported in WTC-exposed firefighters but were not associated with EI. This report indicates intense bystander exposure after the WTC collapse and provides information about nonoccupational exposures among a vulnerable population of pregnant women.

Predictors of organochlorines in New York City pregnant women, 1998-2001

Organochlorine compounds (OCs) have been found widely in human tissues. However, levels have been rapidly declining since their virtual ban in the 1970s. We measured 1,1'-dichloro-2,2'-bis(4-chlorophenyl)ethylene (DDE), polychlorinated biphenyls (PCBs), and trans-nonachlor (TN) in 194 pregnant women in New York City and examined demographic and dietary predictors of their levels in serum. Serum OC levels were low (median microg/L: 0.64 DDE, 0.79 PCB); TN was largely below the level of detection (74%). In multivariate models, levels of OCs increased with age; DDE was higher in women not born in the US or Puerto Rico; PCB were higher in women who bought fresh fish and lower in those with higher body mass indices.

Prospective study of blood and tibia lead in women undergoing surgical menopause

Despite the dramatic decline in environmental lead exposure in the United States during the past couple of decades, concern has been expressed regarding mobilization during menopause of existing lead stored in bone. To investigate whether bone lead concentrations decrease and blood lead levels increase, we conducted a prospective study of 91 women who were scheduled to undergo a bilateral oophorectomy for a benign condition at Mount Sinai Hospital in New York City during October 1994 through April 1999. We excluded women who were younger than 30 years of age or who were postmenopausal at the time of the surgery. We observed a small but significant increase in median blood lead levels between the baseline visit and the 6-month visit (0.4 microg/dL, p<0.0001), particularly for women who were not on estrogen replacement therapy (0.7 microg/dL, p=0.008). No significant change was observed in blood lead values between 6 and 18 months postsurgery, nor was there evidence of significant changes in tibia lead concentrations during the follow-up period. These findings do not point to substantial mobilization of lead from cortical bone during menopause.

Characteristics of pubertal development in a multi-ethnic population of nine-year-old girls

PURPOSE

Early age at menarche increases future disease risk. Secular decline in age at menarche has been attributed to body size characteristics, diet, and energy expenditure. Risk factors for puberty have been less frequently explored.

METHODS

A cross-sectional study of 186 New York Metropolitan Area, 9-year-old girls (54 African-American, 70 Hispanic, 62 Caucasians) used interviewer-administered questionnaires to assess exposures. Height and weight were measured. Pediatricians assessed pubertal development according to Tanner stages.

RESULTS

African-Americans were more likely than Caucasians to have achieved puberty as determined by breast or hair development (stage 2 or higher) [age-adjusted odds ratios and 95% confidence intervals = 4.91 (2.15-11.19) and 4.25 (1.85-9.77), respectively]. Pubertal development was similar among Hispanics and Caucasians. Adiposity and height were significantly positively associated with breast or hair development. More sedentary activity hours non-significantly increased the likelihood of hair development. Lower energy, but higher polyunsaturated fat, consumption were suggestive of an association with breast development. Vitamin C and hair development were inversely related. No other nutrients or physical activity measures were related to pubertal development.

CONCLUSIONS

Results are consistent with height and adiposity being associated with pubertal development. Sedentary activity or diet might possibly influence maturation.

Study design: evaluating gene-environment interactions in the etiology of breast cancer - the WECARE study

INTRODUCTION

Deficiencies in cellular responses to DNA damage can predispose to cancer. Ionizing radiation can cause cluster damage and double-strand breaks (DSBs) that pose problems for cellular repair processes. Three genes (ATM, BRCA1, and BRCA2) encode products that are essential for the normal cellular response to DSBs, but predispose to breast cancer when mutated.

DESIGN

To examine the joint roles of radiation exposure and genetic susceptibility in the etiology of breast cancer, we designed a case-control study nested within five population-based cancer registries. We hypothesized that a woman carrying a mutant allele in one of these genes is more susceptible to radiation-induced breast cancer than is a non-carrier. In our study, 700 women with asynchronous bilateral breast cancer were individually matched to 1400 controls with unilateral breast cancer on date and age at diagnosis of the first breast cancer, race, and registry region, and counter-matched on radiation therapy. Each triplet comprised two women who received radiation therapy and one woman who did not. Radiation absorbed dose to the contralateral breast after initial treatment was estimated with a comprehensive dose reconstruction approach that included experimental measurements in anthropomorphic and water phantoms applying patient treatment parameters. Blood samples were collected from all participants for genetic analyses.

CONCLUSIONS

Our study design improves the potential for detecting gene-environment interactions for diseases when both gene mutations and the environmental exposures of interest are rare in the general population. This is particularly applicable to the study of bilateral breast cancer because both radiation dose and genetic susceptibility have important etiologic roles, possibly by interactive mechanisms. By using counter-matching, we optimized the informativeness of the collected dosimetry data by increasing the variability of radiation dose within the case-control sets and enhanced our ability to detect radiation-genotype interactions.

In utero pesticide exposure, maternal paraoxonase activity, and head circumference

Although the use of pesticides in inner-city homes of the United States is of considerable magnitude, little is known about the potentially adverse health effects of such exposure. Recent animal data suggest that exposure to pesticides during pregnancy and early life may impair growth and neurodevelopment in the offspring. To investigate the relationship among prenatal pesticide exposure, paraoxonase (PON1) polymorphisms and enzyme activity, and infant growth and neurodevelopment, we are conducting a prospective, multiethnic cohort study of mothers and infants delivered at Mount Sinai Hospital in New York City. In this report we evaluate the effects of pesticide exposure on birth weight, length, head circumference, and gestational age among 404 births between May 1998 and May 2002. Pesticide exposure was assessed by a prenatal questionnaire administered to the mothers during the early third trimester as well as by analysis of maternal urinary pentachlorophenol levels and maternal metabolites of chlorpyrifos and pyrethroids. Neither the questionnaire data nor the pesticide metabolite levels were associated with any of the fetal growth indices or gestational age. However, when the level of maternal PON1 activity was taken into account, maternal levels of chlorpyrifos above the limit of detection coupled with low maternal PON1 activity were associated with a significant but small reduction in head circumference. In addition, maternal PON1 levels alone, but not PON1 genetic polymorphisms, were associated with reduced head size. Because small head size has been found to be predictive of subsequent cognitive ability, these data suggest that chlorpyrifos may have a detrimental effect on fetal neurodevelopment among mothers who exhibit low PON1 activity.

The CYP3A4*1B variant is related to the onset of puberty, a known risk factor for the development of breast cancer

Breast development, one of the first signs of puberty, is closely associated with age at menarche; and early menarche is in turn a well-established risk factor for female breast cancer. We examined the relationships between the onset of puberty and gene variants for certain enzymes that regulate hormone metabolism among 137 healthy nine-year-old girls from two pediatric clinics. High-activity CYP17 alleles, involved in estrogen formation, and high-activity CYP1A2 and CYP1B1 alleles, whose gene products metabolize estradiol, were not associated with pubertal stage. High activity CYP3A4, but not CYP3A5, which primarily metabolizes testosterone, showed a striking association with the onset of puberty (adjusted odds ratio, 3.21; 95% confidence interval, 1.62-6.89 for the genotype 0-1-2 rapid alleles). Of the homozygous CYP3A4*1B/1B girls, 90% had reached puberty; whereas, for the low-activity homozygous CYP3A4*1A/1A individuals, only 40% had done so. In heterozygotes, 56% had reached puberty. CYP1B1, CYP3A4, and CYP3A5 rapid variants were more common in African-American than in Hispanic or Caucasian girls.

Exposure to indoor pesticides during pregnancy in a multiethnic, urban cohort

Evidence is growing that indoor pesticide exposure is of considerable magnitude in the United States and that pesticide concentrations may be especially high in urban areas. Of particular concern is exposure of pregnant women because animal data suggest that exposure to pesticides during pregnancy and early life may impair neurodevelopment in the offspring. To investigate the relationship between prenatal exposure to indoor pesticides and infant growth and development, we are conducting a prospective, multiethnic cohort study of mothers and infants delivered at Mount Sinai Hospital in New York City. This article provides data on pesticide exposure based on questionnaire items and analysis of maternal urinary metabolite levels among 386 women. Both the questionnaire and laboratory data revealed that exposure to indoor pesticides was considerable. The proportion of women estimated from questionnaire data as having been exposed during pregnancy to indoor pesticides (approximately 70%) was somewhat lower than the 80-90% of American households who reportedly used pesticides in previous surveys, but some of the latter surveys included both indoor and outdoor pesticide use. Urinary metabolite levels of 3,5,6-trichloro-2-pyridinol (TCPy; median = 11.3 micro g/g creatinine), phenoxybenzoic acid (PBA; median =19.3 micro g/g creatinine), and pentachlorophenol (PCP; median =7.3 micro g/g creatinine) were higher than those reported in other studies of adults in the United States. Furthermore, no associations were evident between the pesticide questionnaire data and the urinary metabolites. Assessments of sociodemographic and building characteristics with questionnaire data and the metabolite levels revealed no consistent trends. Significant temporal variations were observed for urinary PBA but not TCPy or PCP. The temporal variations for PBA were consistent with seasonal spraying of pyrethroid pesticides. These data underscore the need to assess the potentially adverse effects of pesticide exposure on fetuses and infants and the importance of finding alternative methods for pest management to reduce pesticide exposures.

The Long Island Breast Cancer Study Project: description of a multi-institutional collaboration to identify environmental risk factors for breast cancer

The Long Island Breast Cancer Study Project is a federally mandated, population-based case-control study to determine whether breast cancer risk among women in the counties of Nassau and Suffolk, NY, is associated with selected environmental exposures, assessed by blood samples, self-reports, and environmental home samples. This report describes the collaborative project's background, rationale, methods, participation rates, and distributions of known risk factors for breast cancer by case-control status, by blood donation, and by availability of environmental home samples. Interview response rates among eligible cases and controls were 82.1% (n = 1,508) and 62.8% (n = 1,556), respectively. Among case and control respondents who completed the interviewer-administered questionnaire, 98.2 and 97.6% self-completed the food frequency questionnaire; 73.0 and 73.3% donated a blood sample; and 93.0 and 83.3% donated a urine sample. Among a random sample of case and control respondents who are long-term residents, samples of dust (83.6 and 83.0%); soil (93.5 and 89.7%); and water (94.3 and 93.9%) were collected. Established risk factors for breast cancer that were found to increase risk among Long Island women include lower parity, late age at first birth, little or no breast feeding, and family history of breast cancer. Factors that were found to be associated with a decreased likelihood that a respondent would donate blood include increasing age and past smoking; factors associated with an increased probability include white or other race, alcohol use, ever breastfed, ever use of hormone replacement therapy, ever use of oral contraceptives, and ever had a mammogram. Long-term residents (defined as 15+ years in the interview home) with environmental home samples did not differ from other long-term residents, although there were a number of differences in risk factor distributions between long-term residents and other participants, as anticipated.

1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene and Polychlorinated Biphenyls and Breast Cancer: Combined Analysis of Five U.S. Studies

BACKGROUND

Environmental exposure to organochlorines has been examined as a potential risk factor for breast cancer. In 1993, five large U.S. studies of women located mainly in the northeastern United States were funded to evaluate the association of levels of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and polychlorinated biphenyls (PCBs) in blood plasma or serum with breast cancer risk. We present a combined analysis of these results to increase precision and to maximize statistical power to detect effect modification by other breast cancer risk factors.

METHODS

We reanalyzed the data from these five studies, consisting of 1400 case patients with breast cancer and 1642 control subjects, by use of a standardized approach to control for confounding and assess effect modification. We calculated pooled odds ratios (ORs) and 95% confidence intervals (CIs) by use of the random-effects model. All statistical tests were two-sided.

RESULTS

When we compared women in the fifth quintile of lipid-adjusted values with those in the first quintile, the multivariate pooled OR for breast cancer associated with PCBs was 0.94 (95% CI = 0.73 to 1.21), and that associated with DDE was 0.99 (95% CI = 0.77 to 1.27). Although in the original studies there were suggestions of elevated breast cancer risk associated with PCBs in certain groups of women stratified by parity and lactation, these observations were not evident in the pooled analysis. No statistically significant associations were observed in any other stratified analyses, except for an increased risk with higher levels of PCBs among women in the middle tertile of body mass index (25-29.9 kg/m(2)); however, the risk was statistically nonsignificantly decreased among heavier women.

CONCLUSIONS

Combined evidence does not support an association of breast cancer risk with plasma/serum concentrations of PCBs or DDE. Exposure to these compounds, as measured in adult women, is unlikely to explain the high rates of breast cancer experienced in the northeastern United States.

Lack of effect of psychosocial stress on maternal corticotropin-releasing factor and catecholamine levels at 28 weeks' gestation

OBJECTIVE

Corticotropin-releasing factor (CRF) and catecholamines are among the major hormones activated during the adaptive response to stressful stimuli. In pregnant women, serum CRF and catecholamines levels increase during labor and preterm delivery. The aim of the present study was to evaluate whether psychosocial stress measures are correlated with serum CRF or urinary catecholamine [ie, epinephrine, norepinephrine (NE), dopamine (DA)] levels in healthy midtrimester pregnant women.

METHODS

A large group of white pregnant women (n = 382) participated in the present study. The Work Conditions Questionnaire and the Psychiatric Epidemiology Research Interview were administered to measure job stress and general life stress, respectively. Urine and blood specimens were collected at 28 weeks of gestation at the time of psychosocial evaluation. Epinephrine, NE, and DA were quantified in the urine by a highly sensitive method based on an amperometric detector. Serum CRF and cortisol levels were measured in blood specimens by using specific radioimmunoassays.

RESULTS

Serum CRF and cortisol levels did not vary between patients with high and low scores on psychological tests, and no correlation was found between CRF and cortisol levels. One job stress measure, low job latitude, was significantly associated with a mild increase in NE and DA levels in the afternoon and night (P < .05, analysis of variance). Serum cortisol levels were inversely correlated with NE in the morning (r = -0.447; P =.002) and night segments (r = -0.391; P = .007) and with DA in the night period (r = -0.367; P = .013).

CONCLUSION

The absence of a significant relationship between CRF/cortisol and psychosocial stress measures in pregnant women suggests that the hypothalamic-pituitary-adrenal response to psychosocial stress may be masked at midtrimester by the constantly high levels of placental CRF, whose control is beyond the influence of environmental stressors.

The rationale for a national prospective cohort study of environmental exposure and childhood development

Evidence is growing that pre- and perinatal exposures and factors play a role in not only childhood but adulthood disorders. Therefore, there is a compelling need to undertake a national cohort study to evaluate the effects of such factors, ideally through adult life. Several recent developments, including advancements in computer technology, the management, storage, and analysis of biological specimens, and the rapid growth of genetic markers, facilitate the evaluation of the influence of environmental exposures on the subsequent risk of developmental abnormalities and disease. The rationale behind the establishment of such a cohort is discussed.

Organochlorine exposures and breast cancer risk in New York City women

A hospital-based case-control study of breast cancer risk related to organochlorine (OC) exposure was conducted in a multiethnic setting in New York City. We enrolled 175 breast cancer patients and 355 control patients. The overall racial/ethnic distribution was 57% Caucasian, 21% Hispanic, 22% African-American; cases and controls were frequency-matched by age and race/ethnicity. Tumor markers (estrogen and progesterone receptors, p53, erbB-2) were assessed and organochlorines (DDE, DDT, trans-nonachlor, and higher (HPCB) and lower (LPCB) chlorinated biphenyls) were measured in blood serum. Tumors among minority women were of slightly higher stage than among Caucasians, but tumor markers were similar across the racial/ethnic groups. DDE levels were highest among African-American and Hispanic women; DDT was highest among Hispanics; HPCBs were highest among African-Americans; LPCBs were lowest among Hispanics; and trans-nonachlor was highest among African-Americans. However, OC levels were not associated with risk for breast cancer, nor did OCs differ with respect to tumor stage or tumor markers. Higher DDE levels were associated with increasing body mass index (BMI), but with decreasing level of education, frequency of nulliparity, and frequency of family history of breast cancer. HPCB levels decreased with BMI and were not correlated with breast cancer risk factors. These relationships can be attributed to historical patterns of exposure and to metabolic differences in OCs related to BMI.

Methodological issues related to studies of lead mobilization during menopause

While there has been a substantial decline in lead exposure in the United States during the past two decades, mobilization of existing lead stored in bone potentially represents an important endogenous source of exposure for menopausal women. It has been hypothesized that lead may be mobilized from skeletal stores during conditions of high bone turnover, such as during menopause. However, such mobilization has not been documented in prospective studies. This discussion is focussed on some of the methodological difficulties to be anticipated in longitudinal studies of lead mobilization specific to menopause and the issues that need to be taken into account when evaluating the results of such studies. To evaluate whether lead mobilization occurs during menopause, a prospective repeated measures design is needed using X-ray fluorescence analysis of lead in bone and serial measurements of blood lead. Potential confounders and effect modifiers also need to be taken into account in the statistical analysis.

Lead exposure among young urban women

OBJECTIVE

Blood lead levels have declined among every age group in the United States, but urban minority residents remain at disproportionate risk for elevated lead levels. Our objective was to measure lead burden in young women of childbearing age in New York City. We also describe successful means of recruiting this population into a cohort study.

MATERIAL AND METHODS

Healthy women aged 18-25 attending a New York City health care center in 1995-1998 were eligible for participation. Participants were recruited by health care providers, the study coordinator and the participants themselves. Venous blood samples were obtained for whole blood lead, ferritin and hematocrit measurements, and detailed questionnaires were administered.

RESULTS

239 women have been recruited to date. The population is predominately minority: 62% African-American, 33% Hispanic and 5% Caucasian/Asian. The average age of participants is 19.3 years. Recruitment of participants into the study is predominantly (55%) through "word of mouth" from previously enrolled participants. Few participants learned of the study through their health care providers. The mean blood lead level among study participants is 2.1 +/- 1.7 micrograms/dl, which is consistent with the most recent United States national survey.

CONCLUSIONS

Blood lead levels are low in young, urban minority women of childbearing age in New York City. In this population, recruitment efforts were substantially enhanced with the help of enrolled participants and the health care community.

Concordance among measures of pregnancy outcome based on fetal size and duration of gestation

Epidemiologic and clinical studies of pregnancy outcome often consider a variety of related, overlapping outcome measures. The overlap among these measures was analyzed using data from the Mount Sinai Hospital Perinatal Data Base, New York City, New York. A total of 52,621 births from 1986 through 1996 were included, with information on gender, ethnicity, birth weight, and gestational age assigned based on last menstrual period or early ultrasound. The authors considered very low birth weight (VLBW) (<1,500 g), low birth weight (LBW) (<2,500 g), degrees of preterm delivery (less than 32, 34, and 37 weeks' gestation), and small for gestational age (less than the 10th percentile of weight for gestational age) births. Infants at the extremes of gestational age (<32 or 34 weeks' gestation) were almost always LBW (97.6 and 91.7%, respectively), and those who were VLBW were almost always preterm (99.2%). However, only 69.2% of LBW infants were preterm, and 50.2% of preterm infants were LBW (kappa = 0.54). Only for VLBW and less than 32 weeks' gestation were both measures of overlap at least 70% (kappa = 0.98). The lack of concordance among measures suggests that multiple outcome measures be considered and that results from analyses using disparate measures not be compared directly.

Placental abruption and adverse perinatal outcomes

CONTEXT

Pregnancies complicated by abruption result in increased frequency of perinatal death and decreased fetal size and gestational duration, yet the extent of placental separation and its effect on these adverse outcomes is unknown.

OBJECTIVE

To assess the contribution of placental abruption and extent of placental separation to stillbirth, preterm delivery, and fetal growth restriction.

DESIGN

Hospital-based, retrospective cohort study.

SETTING

Mount Sinai Hospital, New York City, NY.

PARTICIPANTS

A total of 53,371 pregnancies occurring in 40,789 women who were delivered of singleton births between 1986 and 1996.

MAIN OUTCOME MEASURES

Risks and relative risks for stillbirth (>20 weeks), preterm delivery (<37 weeks), and fetal growth restriction (birth weight below 10th percentile for gestational age) in relation to abruption.

RESULTS

The incidence of abruption was 1 % (n = 530). Abruption was associated with an 8.9-fold (95% confidence interval [CI], 6.0-13.0) adjusted relative risk (aRR) of stillbirth. Preterm birth proportions among women with and without abruption were 39.6% and 9.1 %, respectively, yielding an aRR of 3.9 (95% CI, 3.5-4.4). In the abruption group, 14.3% of neonates were growth restricted, compared with 8.1 % among all other births (aRR, 2.0; 95% CI, 1.5-2.4). Extent of placental separation had a profound effect on stillbirth (aRR for 75% separation, 31.5; 95% CI, 17.0-58.4), although evident only among those with at least 50% separation. However, the risk of preterm delivery was substantially increased even for mild abruptions (aRR for 25% separation, 5.5; 95% CI, 4.2-7.3).

CONCLUSIONS

In this cohort, placental abruption had a profound impact on stillbirth, preterm delivery, and fetal growth restriction. The risk of stillbirth was dramatically increased for severe placental separation, but preterm delivery was common even among women with lesser degrees of placental separation.

Pesticides and inner-city children: exposures, risks, and prevention

Six million children live in poverty in America's inner cities. These children are at high risk of exposure to pesticides that are used extensively in urban schools, homes, and day-care centers for control of roaches, rats, and other vermin. The organophosphate insecticide chlorpyrifos and certain pyrethroids are the registered pesticides most heavily applied in cities. Illegal street pesticides are also in use, including tres pasitos (a carbamate), tiza china, and methyl parathion. In New York State in 1997, the heaviest use of pesticides in all counties statewide was in the urban boroughs of Manhattan and Brooklyn. Children are highly vulnerable to pesticides. Because of their play close to the ground, their hand-to-mouth behavior, and their unique dietary patterns, children absorb more pesticides from their environment than adults. The long persistence of semivolatile pesticides such as chlorpyrifos on rugs, furniture, stuffed toys, and other absorbent surfaces within closed apartments further enhances urban children's exposures. Compounding these risks of heavy exposures are children's decreased ability to detoxify and excrete pesticides and the rapid growth, development, and differentiation of their vital organ systems. These developmental immaturities create early windows of great vulnerability. Recent experimental data suggest, for example, that chlorpyrifos may be a developmental neurotoxicant and that exposure in utero may cause biochemical and functional aberrations in fetal neurons as well as deficits in the number of neurons. Certain pyrethroids exert hormonal activity that may alter early neurologic and reproductive development. Assays currently used for assessment of the toxicity of pesticides are insensitive and cannot accurately predict effects to children exposed in utero or in early postnatal life. Protection of American children, and particularly of inner-city children, against the developmental hazards of pesticides requires a comprehensive strategy that monitors patterns of pesticide use on a continuing basis, assesses children's actual exposures to pesticides, uses state-of-the-art developmental toxicity testing, and establishes societal targets for reduction of pesticide use.

Risk factors for preterm birth subtypes

To assess epidemiologic risk factors for preterm birth subcategories in an urban population, we undertook a study of 31,107 singleton livebirths that took place at Mount Sinai Hospital in New York City between 1986 and 1994. We subdivided the preterm births into preterm premature rupture of the membranes, preterm labor, and medically induced births. We obtained information regarding the preterm subtypes and their epidemiologic risk factors from a computerized perinatal database. Adjusted odds ratios showed an increased risk for all three preterm birth subtypes in women who were black (1.9 for preterm premature rupture of membranes, 2.1 for preterm labor, and 1.7 for medically induced births) or Hispanic (1.7 for preterm premature rupture of membranes, 1.9 for preterm labor, and 1.6 for medically induced births), those who had had a previous preterm birth (3.2 for preterm premature rupture of membranes, 4.5 for preterm labor, and 3.3 for medically induced births), those who began prenatal care after the first trimester ( 1.4 for preterm premature rupture of membranes, 1.3 for preterm labor, and 1.3 for medically induced births), women who had been exposed to diethylstilbestrol in utero (3.1 for preterm premature rupture of membranes, 4.1 for preterm labor, and 3.7 for medically induced births), patients with preexisting diabetes mellitus (2.2 for preterm premature rupture of membranes, 2.4 for preterm labor, and 9.5 for medically induced births), and those with antepartum bleeding (2.8 for preterm premature rupture of membranes, 3.6 for preterm labor, and 3.7 for medically induced births). Other sociodemographic, constitutional, life-style, and obstetrical characteristics differed across the groups. Variation in some of the risk factors among the preterm subtypes implies that epidemiologic assessment of the more specific outcomes would be advisable.

p53 haplotype determination in breast cancer

Inheritance of certain germ line haplotypes consisting of three biallelic polymorphisms of p53 has been proposed as a risk factor for breast cancer and colorectal cancer [A. Själander et al., Carcinogenesis (Lond.), 17: 1313-1316, 1996, and Carcinogenesis (Lond.), 16: 1461-1464, 1995]. In their studies, pairwise haplotypes of these three polymorphisms were estimated. Extended haplotypes were further projected from the pairwise combinations. To overcome the necessity to estimate pairwise and extended haplotype frequencies, a PCR method has been developed to determine the absolute extended p53 haplotypes in diploid genomes. The method requires allele-specific PCR, confirmed by restriction analysis, and successive amplicon analysis. It has been applied to a nested case-control study of breast cancer (284 subjects; 99 cases and 185 controls; 182 Caucasians, 56 Hispanics, and 46 African-Americans). Evidence is presented that minor variants of the intron 3, codon 72, and intron 6 polymorphisms were moderately elevated in Caucasian breast cancer cases (intron 3, P = 0.03 for genotype and P = 0.01 for allelic frequency; codon 72, P = 0.07 for genotype and P = 0.054 for allelic frequency; and intron 6, P = 0.02 for genotype and P = 0.02 for allele frequency). Accordingly, analysis of haplotype distributions suggested an association of minor p53 haplotypes with breast cancer risk in Caucasians (P = 0.07). The relative allelic frequencies in breast cancer cases compared with controls also differed by age and menopausal status; the 1-2-1 haplotype was overrepresented in postmenopausal cases (P = 0.02) and cases older than 50 years (P = 0.02), whereas the other minor haplotypes (1-1-2 and rare variants) were overrepresented in premenopausal cases (P = 0.003) and cases 50 years of age and younger (P = 0.02). Genotype distributions at each locus and for all control groups were consistent with Hardy-Weinberg equilibria. Differences in haplotype distribution were associated with ethnicity (Caucasians versus African-Americans and Caucasians versus Hispanics, P < 0.001). The new haplotyping method may be useful in the study of gene-environment interactions.

Corticotropin-releasing factor and its binding protein: maternal serum levels in term and preterm deliveries

OBJECTIVE

The primary objective of this investigation was to evaluate whether maternal serum corticotropin-releasing factor levels during pregnancy were predictive of spontaneous preterm delivery.

STUDY DESIGN

Maternal serum levels of corticotropin-releasing factor and its binding protein were measured from 20 weeks of gestation in a cross-sectional study of 396 asymptomatic women at high risk for preterm delivery.

RESULTS

Gestational age-specific corticotropin-releasing factor levels were not consistently or substantially increased for preterm compared with term deliveries, whether preterm delivery was due to preterm labor or preterm premature rupture of membranes. The binding protein for corticotropin-releasing factor did not vary according to gestational age until term, when it dropped substantially.

CONCLUSION

Serum corticotropin-releasing factor levels do not appear to be an important predictor of preterm birth in asymptomatic patients who subsequently have either preterm labor or preterm premature rupture of membranes. Nevertheless, the drop in the corticotropin-releasing factor binding protein level at term suggests that the bioavailability of corticotropin-releasing factor increases as parturition approaches.

The role of DDE and polychlorinated biphenyl levels in preterm birth

Maternal serum levels of DDE and polychlorinated biphenyls (PCB) and their congeners were compared for 20 women who had a spontaneous preterm delivery and 20 matched women who had delivered at term at Mount Sinai Medical Center in New York between October 1990 and August 1993. Since no substantial case-control differences were evident, these findings do not indicate that increased DDE or PCB levels are associated with spontaneous preterm birth.

Risk factors for cryptorchidism: a nested case-control study

A nested case-control study of cryptorchidism (i.e. undescended testicles) was undertaken as part of a hospital-based cohort study of 6699 singleton male neonates in New York City. Since some of the cryptorchid infants experienced spontaneous descent of their testes, separate analysis was performed for this third group of 'late descenders' (n=140). Cases (n=63) represented infants whose testes remained undescended at the one year assessment. Controls (n=219) represented the next male infant who was delivered immediately after an infant who was cryptorchid at birth. The only independent risk factors for cryptorchidism were Asian ethnic group (adjusted odds ratio (OR) = 3.90, 95% confidence interval (CI) = 1.22-12.41), swollen legs or feet during pregnancy (adjusted OR = 2.16, 95% CI = 1.15-4.04), a family history of cryptorchidism (adjusted OR = 4.32, 95% CI = 1.91-9.80), low birthweight (adjusted OR = 4.10, 95% CI = 1.39-12.08), and use of analgesics during pregnancy (adjusted OR = 1.93, 95% CI = 1.03-3.62). Multiple logistic regression analysis was also performed to identify those factors that were associated with late testicular descent. In this analysis the independent risk factors were black or Hispanic ethnicity (adjusted OR = 2.05, 95% CI = 1.09-3.83), a family history of cryptorchidism (adjusted OR = 4.25, 95% CI = 1.84-9.78), consumption of cola-containing drinks during the pregnancy (adjusted OR = 2.09, 95% CI = 1.10-3.99), a low birthweight delivery (adjusted OR = 9.78, 95% CI = 3.39-28.20), and preterm birth (adjusted OR = 4.01, 95% CI = 1.66-9.70).

Corticotropin-releasing hormone and related pituitary-adrenal axis hormones in fetal and maternal blood during the second half of pregnancy

There is little information available concerning the ontologic development of the human hypothalamic-pituitary-adrenal (HPA) axis nor of the potential interactions among fetal, maternal and placental-derived HPA axis hormones. This study evaluated levels of these hormones in matched maternal and fetal pairs during the second half of uncomplicated pregnancies. Immunoassays were used to measure serum concentrations of corticotropin-releasing hormone (CRH), adrenocorticotropin (ACTH) and cortisol in 104 matched fetal and maternal blood samples. Fetal specimens were obtained by percutaneous umbilical blood sampling (PUBS) between 18 and 40 weeks in patients whose pregnancies resulted in healthy, term infants. Correlations among these hormones, and the effect of gestational age were assessed. Maternal CRH concentrations [median (range)] [1.10 ng/ml (0.15 to 23.69)] were significantly greater than fetal values [0.35 ng/ml (0.07 to 1.0)]. Levels of maternal CRH (r = 0.73; p < 0.001) but not fetal CRH (r = 0.01; p = 0.98) correlated with gestational age. Maternal ACTH decreased (r = -0.21; p = 0.04) while fetal ACTH increased (r = 0.35; p < 0.003) with gestational age. Both maternal (r = 0.45; p < 0.001) and fetal (r = 0.57; p < 0.001) cortisol levels increased with gestational age. Maternal serum CRH values correlated best with fetal cortisol (r = 0.40; p = 0.0002) and correlated modestly with maternal cortisol (r = 0.28; p = 0.01), fetal ACTH (r = 0.24; p = 0.03) and fetal CRH (r = 0.23; p = 0.04); but not with maternal ACTH (r = -0.12; p = 0.3). Maternal CRH concentrations increase in the third trimester and correlate with rising fetal cortisol levels.

Employment-related physical activity and pregnancy outcome

Concern about possible adverse reproductive effects of employment reflects the increasing participation of pregnant women in the labor force. Although the literature on the effect of employment-related physical activity on pregnancy outcome is substantial, no general consensus has been reached. A growing number of studies, however, suggests that prolonged standing and long working hours may pose a risk to pregnancy. The provision of maternity benefits varies greatly between the United States and European countries. Current modifications of working conditions for both pregnant and non-pregnant women differ even among European countries.

Working conditions, maternity legislation, and preterm birth

The review of the scientific literature on the role of employment-related physical activity suggests that prolonged standing and long working hours may increase the risk of preterm delivery. Although maternity legislation in many European countries has regulated work schedules and working conditions for pregnant women, none of the European countries except for France seems to have experienced a reduction in preterm rates. France has had both a comprehensive maternity legislation and a national program specifically aimed to reduce preterm birth. Despite the lack of reduction in preterm rates, paid maternity leave, guaranteed job protection, and regulation of hazardous working conditions remain a desirable societal goal for any industrialized nation.

Maternal and neonatal risk factors for cryptorchidism

We assessed risk factors for cryptorchidism in a prospective hospital-based cohort study at Mount Sinai Hospital in New York City. We examined at birth 6,699 singleton male neonates who were delivered between October 1987 and October 1990. Follow-up examinations were undertaken at 3 months and 1 year for those diagnosed as cryptorchid at birth. We calculated prevalence ratios and adjusted odds ratios according to selected maternal and neonatal characteristics for those who remained cryptorchid at the 1-year assessment. We found elevated risks for maternal obesity [prevalence ratio = 2.42; 95% confidence interval (CI) = 1.11-5.27], for infants delivered by cesarean section (adjusted odds ratio = 2.17; 95% CI = 1.29-3.65), for low birthweight (adjusted odds ratio = 2.29; 95% CI = 1.12-4.70), for preterm birth (adjusted odds ratio = 2.25; 95% CI = 1.16-4.35), and for infants with congenital malformations (prevalence ratio = 13.97; 95% CI = 1.27-26.67). We observed a seasonal effect, with a peak in births of cryptorchid infants during September through November and a smaller peak during the months of March through May. We found no evidence that young women, white women, or primiparas were at increased risk.

An estrogen receptor genetic polymorphism and the risk of primary and secondary recurrent spontaneous abortion

OBJECTIVE

A case-control study was undertaken to assess the association between an estrogen receptor gene variant and the risk of recurrent spontaneous abortions.

STUDY DESIGN

The frequency of the estrogen receptor gene variant in blood lymphocyte deoxyribonucleic acid and other selected maternal characteristics was compared among 60 primary recurrent aborters, 61 secondary recurrent aborters, and 43 women who had had at least two live births but no spontaneous abortions.

RESULTS

No association was evident between the estrogen receptor gene variant and the risk of either primary or secondary recurrent abortion. There were data suggesting that primary recurrent aborters in particular were more likely to report a family history of recurrent abortion and a family history of breast cancer.

CONCLUSIONS

These findings indicate that the estrogen receptor polymorphism is not a genetic marker for recurrent spontaneous abortions. Therefore, as suggested by previous investigations, this polymorphism appears to be a marker for breast cancer risk only among the subgroups who have had a history of repeated abortions.

Association of an estrogen receptor variant with increased height in women

There is an association between a B region allele (here called the B' allele) of the estrogen receptor (ER) and a history of spontaneous abortion in women with ER positive breast cancer, but no such association for women with ER negative tumors or women without breast cancer. In this study we compared the heights of women carrying the B and B' alleles. The B' allele was identified by polymerase chain reaction to amplify genomic DNA around the polymorphic region of the ER gene, followed by allele specific oligonucleotide hybridization. This analysis used DNA obtained from blood lymphocytes. Women carrying the B' allele were significantly taller than those carrying the wild type allele (B allele). Multiple linear regression also demonstrated that this association remained (p = 0.017), controlling for the effects of age and race. Since the B' ER allele results from a silent mutation, a second mutation, segregating with it, no doubt plays a role in producing the high incidence of spontaneous abortion we reported previously and the height difference we report here. This second mutation might lie within the estrogen receptor itself or within one of the genes nearby.

Fractured clavicle in the neonate: a retrospective three-year review

A hospital-based case-controlled study was undertaken to determine maternal and neonatal characteristics associated with fractured clavicle. A total of 11,604 consecutive vaginal deliveries of liveborn infants in vertex presentation at the Mount Sinai Hospital from 1988 to 1990 were reviewed. Maternal and neonatal characteristics were compared for the neonates with and without a diagnosis of a fractured clavicle. Compared to controls, mothers of neonates with a fractured clavicle were more likely to be nulliparas or primiparas, to have had an operative vaginal delivery, and to have been delivered by an attending as opposed to a resident physician. The fractured clavicle group also had a longer gestational age, greater birthweight, and higher frequency of macrosomic infants. After controlling for maternal parity, type of delivery and infant birthweight, experience of the delivering physician, and gestational age at delivery were not significantly different. Fracture of the clavicle in the neonate is related to maternal parity, mode of delivery, and infant birthweight but not to the level of experience of the delivering physician.

Risk factors for severe preeclampsia

OBJECTIVE

To identify risk factors associated with severe preeclampsia and to determine whether these factors are similar in nulliparous and multiparous patients.

METHODS

Patients whose pregnancies were complicated by severe preeclampsia (n = 70) were compared retrospectively to 18,964 non-preeclamptic controls. Information on maternal demographic factors; medical, obstetric, and family histories; and neonatal outcome was retrieved and analyzed by univariate and multivariate analysis.

RESULTS

By logistic regression, the only risk factors associated with the development of severe preeclampsia were severe obesity in all patients (adjusted odds ratio 3.5, 95% confidence interval [CI] 1.68-7.46) and a history of preeclampsia in multiparous patients (adjusted odds ratio 7.2, 95% CI 2.74-18.74).

CONCLUSION

Severe obesity and a history of preeclampsia are the only maternal risk factors identified for the development of severe preeclampsia.

Prevalence and natural history of cryptorchidism

OBJECTIVE

A prospective hospital-based cohort study was conducted to determine the prevalence rates of cryptorchidism at birth, 3 months, and 1 year of age.

DESIGN

A total of 6935 consecutive male neonates delivered at Mount Sinai Hospital in New York City between October 1987 and October 1990 were examined at birth for cryptorchidism. Standardized examination and classification criteria were used. Infants classified as cryptorchid at birth were reexamined at 3 months and 1 year after the expected date of delivery.

RESULTS

Of 6935 neonates assessed at birth, 255 (3.7%) were found to be cryptorchid at birth. The rates were significantly elevated for low birth weight, preterm, small-for-gestational age, and twin neonates. The overall rate had declined to 1.0% by the 3-month assessment and 1.1% at the 1-year assessment. Although the rates at the 1-year assessment tended to be higher for low birth weight and preterm infants, no significant group differences were observed.

CONCLUSIONS

Since the prevalence rates in this study are similar to those reported several decades ago, these data provide no evidence that the rate of cryptorchidism has increased either at birth or by 1 year of age. Furthermore, most testes that descend spontaneously do so within the first 3 months after the expected date of delivery.

Association between pregnancy-induced hypertension and asthma during pregnancy

OBJECTIVE

Pregnancy-induced hypertension is an important cause of maternal mortality, intrauterine growth retardation, and perinatal mortality. We examined the relationship between pregnancy-induced hypertension and asthma.

STUDY DESIGN

The study population consisted of 24,115 women without a history of chronic systemic hypertension who were delivered of live born and stillborn infants at Mount Sinai Medical Center between January 1987 and December 1991. Pregnancy-induced hypertension was defined as blood pressure of at least 140/90 mm Hg or an increase of > or = 30 mm Hg in systolic pressure or > or = 15 mm Hg in diastolic pressure.

RESULTS

There was a significant association between pregnancy-induced hypertension and asthma during pregnancy (chi 2 = 17.86, p < 0.001). In addition, there was a significant upward trend in the incidence of asthma during pregnancy in women without, with moderate, and with severe pregnancy-induced hypertension (Mantel-Haenszel chi 2 = 11.8, p = 0.001). Logistic regression analysis demonstrated that the association between pregnancy-induced hypertension and asthma during pregnancy persisted after adjustment for the confounding factors of race or ethnicity, maternal age, parity, and prepregnancy weight (adjusted odds ratio 2.52, 95% confidence interval 1.47 to 4.35, p = 0.0008). An association between pregnancy-induced hypertension and a history of asthma was also found (chi 2 = 11.2, p = 0.001). However, after adjustment for potential confounders, this association failed to achieve statistical significance (adjusted odds ratio 1.2, 95% confidence interval 0.97 to 1.53, p = 0.083).

CONCLUSION

Both pregnancy-induced hypertension and asthma might be caused by a third factor affecting smooth muscle reactivity.

Morbidity of failed labor in patients with prior cesarean section

OBJECTIVE

The aim of our study was to determine whether the reported increased morbidity associated with failed attempted vaginal birth after cesarean section is attributable to the presence of a uterine scar alone or to labor preceding a cesarean section.

STUDY DESIGN

Primiparous women (N = 237) who underwent repeat cesarean section after a failed trial of vaginal birth after cesarean section were retrospectively compared with 1582 nulliparous women who underwent a primary cesarean section after a failed trial of labor.

RESULTS

There were no significant differences in maternal or neonatal morbidity between the two groups except for an increase in the prevalence of thin meconium in patients undergoing primary cesarean section.

CONCLUSION

Our results suggest that the presence of a previous cesarean section scar does not increase the overall baseline morbidity associated with cesarean section after labor.

Maternal characteristics, neonatal outcome, and the time of diagnosis of gestational diabetes

OBJECTIVE

A study was undertaken to evaluate the yield of early, routine screening for gestational diabetes and to determine whether maternal characteristics and neonatal outcome differ according to the time of diagnosis.

STUDY DESIGN

A total of 2776 women were screened before 24 weeks of gestation, and each was delivered of a singleton infant on the clinic service of Mount Sinai Hospital in New York City between January 1986 and January 1991.

RESULTS

An abnormal glucose tolerance test was diagnosed in 102 women < 24 weeks and in 252 patients at > or = 24 weeks of gestation. Logistic regression analysis showed that the group diagnosed early was significantly older and more likely to have hypertensive disorders and low maternal weight gain and to require insulin treatment, compared with the group diagnosed late. No significant differences were evident in neonatal outcome.

CONCLUSIONS

These data indicate that a sizable proportion of patients with gestational diabetes can be diagnosed early in pregnancy. The differences in maternal characteristics and insulin requirements between the early- and late-diagnosis groups also suggest heterogeneity of gestational diabetes or the possibility of preexisting impaired glucose intolerance in the early-diagnosis group.

Race/ethnicity and other risk factors for gestational diabetes

Although gestational diabetes is estimated to complicate between 1% and 5% of pregnancies, there are only limited data on the role of race/ethnicity as well as other risk factors in the development of this disorder. Epidemiologic characteristics of gestational diabetes were assessed in an ethnically diverse cohort of 10,187 women who had undergone standardized screening for glucose intolerance and who delivered a singleton infant at the Mount Sinai Medical Center in New York City between January 1987 and December 1989. The overall prevalence of gestational diabetes was 3.2%. Multiple logistic regression analysis showed excess risks for Oriental women, Hispanics born in Puerto Rico or elsewhere outside the United States, women from the Indian subcontinent and the Middle East, older mothers, heavier women, those with a positive family history of diabetes, women with a history of infertility, and those who delivered on the clinic service. These data suggest that, after controlling for traditional risk factors (maternal age, prepregnancy weight, and a family history of diabetes), Orientals, first generation Hispanics, women from the Indian subcontinent and the Middle East, those with a history of infertility, and low socioeconomic status women are at an increased risk for gestational diabetes.

Clinical significance and sonographic diagnosis of velamentous umbilical cord insertion

In order to evaluate the clinical significance of velamentous cord insertion (VCI) and the role of ultrasound in its diagnosis, all 82 cases of VCI during January 1985 to January 1989 at the Mount Sinai Medical Center were reviewed. The overall rate of VCI in our study (0.5%) was similar to that of previous reports. Pregnancy outcomes in VCI patients with 77 singleton gestations were compared with a control group of 15,865 patients. In contrast to the existing literature, multiparity and prior cesarean section deliveries were not increased in pregnancies with VCI. The VCI group had more intrapartum complications and a lower birthweight than the controls. Routine nontargeted obstetric ultrasound failed to detect any cases of VCI, including three cases of vasa previa. Since VCI was not identified prenatally and many of its sequelae are readily identifiable only during the intrapartum period, the potential for preemptive obstetric intervention appears to be limited. In addition, failure to diagnose apparent VCI during a routine ultrasound does not appear to be a departure from the standard of care.