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Irva Hertz-Picciotto

Publications and source records attributed to Irva Hertz-Picciotto.

At least 19 recordsLinked to original sources
PubMed2026

Prenatal cell-free DNA methylome detects association with autism and maternal obesity.

Early identification of autism spectrum disorder (ASD) remains a critical challenge, particularly in utero when non-genetic factors such as maternal obesity (MO) are implicated. Here, we report results of whole-genome bisulfite sequencing of cell-free DNA (cfDNA) from third-trimester maternal plasma in a high-likelihood ASD pregnancy cohort associated with child (3 y) ASD diagnosis and/or MO. Differentially methylated regions (DMRs) between ASD and control cfDNA are strongly enriched for synaptic functions and genes previously implicated in ASD. These cfDNA ASD DMRs recapitulate those observed in ASD placenta and postmortem cortex and significantly overlap with MO DMRs. Our findings establish cfDNA methylation derived from maternal blood as a minimally invasive window into fetal brain ASD etiology, providing a framework for future mechanistic and early intervention studies. Future studies could investigate additional prenatal environmental exposures interacting with genetics during neurodevelopment.

Journal Article↗
PubMed2006

Conditions for bias from differential left truncation.

Spontaneous abortion studies that recruit pregnant women are left truncated because an unknown proportion of the source population experiences losses prior to enrollment. Unconditional logistic regression, commonly used in such studies, ignores left truncation, whereas survival analysis can accommodate left truncation and is therefore more appropriate. This study assessed the magnitude of bias introduced by fitting logistic versus Cox models using left-truncated data from a 1998 US pregnancy cohort study (n = 5,104) of trihalomethanes and spontaneous abortion. In addition, the conditions producing bias were explored by using simulated exposure data. The odds ratios and hazard ratios from the actual study differed by 10% or less. However, when the exposed women entered observation earlier on average than those unexposed, the hazard ratio was closer to the null than the odds ratio, whereas the reverse was true when the exposed entered later. The simulation suggests that bias in the odds ratio will exceed 20% when average gestational age at entry for the exposed versus the unexposed differs by 10 days or more, as has been observed regarding some socioeconomic factors, such as education and ethnicity. Cox regression can correct for left truncation and is no more difficult to perform than logistic regression.

Abortion, Spontaneous↗
PubMed2006

Comparison of organochlorine compound concentrations in colostrum and mature milk.

Human breast milk represents the best choice for the nutrition of infants. It is often used for monitoring human exposures to environmental chemicals. Uniquely suited to meet human biological needs, breast milk composition, especially fat content, changes significantly with time from delivery. With the aim to compare the concentration of organochlorine compounds (OCs) in colostrum versus mature milk, we obtained samples of fourth-fifth day postpartum milk (colostrum) and day-14 postpartum milk (mature milk) from 12 women enrolled in the project "Early Childhood Development and PCB Exposure in Slovakia". The concentrations of selected organochlorine pesticides and congeners of polychlorinated biphenyls (PCBs) were measured using gas chromatography with electron capture detection and reported on lipid adjusted basis. No significant differences were found between organochlorine levels in colostrum and those in mature milk samples. A very close correlation was found between the concentrations of organochlorine compounds in colostrum and mature milk (Spearman correlation coefficient r=0.94-0.98 for PCBs, and r=0.85-0.99 for organochlorine pesticides, p<0.001 for all compounds). The present study concludes that the use of colostrum samples provides a close estimate of the child's exposure to OCs in the early neonatal period and demonstrates that, despite the lower fat content, colostrum specimens are adequate to conduct OC analyses.

Colostrum↗
PubMed2006

Misclassification of gestational age in the study of spontaneous abortion.

Most studies of spontaneous abortion are subject to left truncation, because conception is not observed and thus pregnant women are enrolled postconception. Cox regression can account for left truncation but uses gestational age data, which may be inaccurate. Dating is affected by reporting errors and variability in the day of ovulation. These errors may be differential by outcome, because gestational ages are more likely to be clinically corrected in continuing pregnancies than in pregnancies ending in spontaneous abortion. Errors may be differential by exposure status as well, if exposures affect the time of ovulation. The authors designed a simulation to examine bias caused by errors in gestational age. Pregnancies were assigned true and alternative gestational ages using different assumptions about random reporting error and error due to variation in the time between the last menstrual period and ovulation. In separate scenarios, the errors were differential by outcome, differential by exposure, differential by both exposure and outcome, or nondifferential. Hazard ratios were compared using accurate versus erroneous gestational ages. For proportional hazards, bias was only introduced when the error in gestational age was differential by exposure status. Bias was greatest when the magnitude of error for pregnancies at higher risk was much larger than that for pregnancies at lower risk.

Abortion, Spontaneous↗
PubMed2006

Maternal DDT exposures in relation to fetal and 5-year growth.

BACKGROUND: Dichlorodiphenyltrichloroethane (DDT) is an organochlorine pesticide still used in areas of the world where malaria vector control is needed. Few studies have examined in utero exposures to DDT in relation to fetal and early childhood growth in populations with substantial exposure to DDT. Furthermore, only a portion of these studies have investigated in utero exposures and growth during childhood. METHODS: To assess the role of in utero exposures to DDT on fetal and early childhood growth, we analyzed data from mothers and children who participated in the Child Health and Development Study (CHDS), a cohort study of 20,754 women and their pregnancies conducted in the San Francisco Bay area during the 1960s. We measured p,p'-DDE, o,p'-DDT, and p,p'-DDT concentrations from the stored sera of 399 women collected during pregnancy. Outcomes were measured at the child's birth and at 5 years of age. RESULTS: Maternal p,p'-DDE concentrations were considerable in this study, averaging 6.9 micrograms per gram lipid. After covariate adjustment, a small increase in gestational age was observed with increases in p,p'-DDT and o,p'-DDT, but there was no association with p,p'-DDE. At 5 years of age, an increase from the 25th to the 75th percentile in p,p'-DDE was related to a 2-mm increase in head circumference (95% confidence interval = 0 to 4). Overall effect sizes were small and imprecise. Furthermore, there was little evidence of specificity for a given outcome or exposure at either age. CONCLUSIONS: At the concentrations studied in this sample, DDT compounds did not appear to impair fetal or 5-year growth.

Adult↗
PubMed2006

Association between arsenic exposure from drinking water and anemia during pregnancy.

OBJECTIVE: Arsenic is associated with numerous health effects. We investigated the association between arsenic exposure from drinking water and anemia during pregnancy. METHODS: We conducted a prospective cohort pregnancy study in two Chilean cities with contrasting drinking water arsenic levels: 40 microg/L versus <1 microg/L. This analysis included 810 women who gave birth to live, singleton infants and had at least one hemoglobin determination during pregnancy. RESULTS: Arsenic exposed women were more likely to be anemic during pregnancy after adjusting for other factors. Furthermore, as pregnancy progressed, the prevalence of anemia rose more sharply among those in the exposed versus unexposed city: 49% versus 17%. CONCLUSION: This study suggests an association between moderate arsenic in drinking water and anemia during pregnancy. Further research is needed to identify the specific types of anemia underlying the association.

Adolescent↗
PubMed2006

Child care and social support modify the association between maternal depressive symptoms and early childhood behaviour problems: a US national study.

OBJECTIVE: To investigate the presence and patterns of modification effects of the sex of the child, social support, and childcare on the relation between maternal depressive symptoms and child behaviour problems at two developmental stages. DESIGN: Analyses are based on prospective longitudinal data from the study of early child care. PARTICIPANTS: A total of 1216 families were drawn from 10 locations across the USA. Mothers were age 18 or older at the time of the study child's birth and had completed outcome measures for at least one follow up time point (24 months, 36 months). MAIN OUTCOME MEASURES: Child internalising and externalising behaviour problems assessed at the child's age of 24 months and 36 months, as reported by the mother. RESULTS: Results from generalised estimating equation analyses showed that the association between child externalising behaviour problems and maternal depressive symptoms varied according to the social support received by the mother (p<0.05). Overall, social support mitigated the relation, but protective effects diminished at increasing levels of depressive symptoms. Associations between child internalising behaviour problems and maternal depressive symptoms varied according to whether or not the child received care from caregivers other than the mother (p<0.05). CONCLUSIONS: Health providers who are working with mothers with depressive symptoms may want to examine social support that is available to mothers, especially if mothers are not severely depressed. Furthermore, recommendations to begin, continue, or perhaps increase provision of childcare from other caregivers can provide respite for mothers and opportunities for children to engage in protective interactions with others.

Adolescent↗
PubMed2006

The CHARGE study: an epidemiologic investigation of genetic and environmental factors contributing to autism.

Causes and contributing factors for autism are poorly understood. Evidence suggests that prevalence is rising, but the extent to which diagnostic changes and improvements in ascertainment contribute to this increase is unclear. Both genetic and environmental factors are likely to contribute etiologically. Evidence from twin, family, and genetic studies supports a role for an inherited predisposition to the development of autism. Nonetheless, clinical, neuroanatomic, neurophysiologic, and epidemiologic studies suggest that gene penetrance and expression may be influenced, in some cases strongly, by the prenatal and early postnatal environmental milieu. Sporadic studies link autism to xenobiotic chemicals and/or viruses, but few methodologically rigorous investigations have been undertaken. In light of major gaps in understanding of autism, a large case-control investigation of underlying environmental and genetic causes for autism and triggers of regression has been launched. The CHARGE (Childhood Autism Risks from Genetics and Environment) study will address a wide spectrum of chemical and biologic exposures, susceptibility factors, and their interactions. Phenotypic variation among children with autism will be explored, as will similarities and differences with developmental delay. The CHARGE study infrastructure includes detailed developmental assessments, medical information, questionnaire data, and biologic specimens. The CHARGE study is linked to University of California-Davis Center for Children's Environmental Health laboratories in immunology, xenobiotic measurement, cell signaling, genomics, and proteomics. The goals, study design, and data collection protocols are described, as well as preliminary demographic data on study participants and on diagnoses of those recruited through the California Department of Developmental Services Regional Center System.

Adult↗
PubMed2006

Coal home heating and environmental tobacco smoke in relation to lower respiratory illness in Czech children, from birth to 3 years of age.

OBJECTIVE: The objective of this study was to evaluate how indoor pollution from tobacco and home heating may adversely affect respiratory health in young children. DESIGN: A birth cohort was followed longitudinally for 3 years to determine incidence of lower respiratory illness (LRI). PARTICIPANTS: A total of 452 children born 1994-1996 in two districts in the Czech Republic participated. EVALUATIONS: Indoor combustion exposures were home heating and cooking fuel, mother's smoking during pregnancy, and other adult smokers in the household. Diagnoses of LRI (primarily acute bronchitis) from birth to 3 years of age were abstracted from pediatric records. Questionnaires completed at delivery and at 3-year follow-up provided covariate information. LRI incidence rates were modeled with generalized linear models adjusting for repeated measures and for numerous potential confounders. RESULTS: LRI diagnoses occurred more frequently in children from homes heated by coal [vs. other energy sources or distant furnaces ; rate ratio (RR) = 1.45 ; 95% confidence interval (CI) , 1.07-1.97]. Maternal prenatal smoking and other adult smokers also increased LRI rates (respectively: RR = 1.48 ; 95% CI, 1.10-2.01 ; and RR = 1.29 ; 95% CI, 1.01-1.65) . Cooking fuels (primarily electricity, natural gas, or propane) were not associated with LRI incidence. For children never breast-fed, coal home heating and mother's smoking conferred substantially greater risks: RR = 2.77 (95% CI, 1.45-5.27) and RR = 2.52 (95% CI, 1.31-4.85) , respectively. CONCLUSIONS: Maternal smoking and coal home heating increased risk for LRI in the first 3 years of life, particularly in children not breast-fed. RELEVANCE: Few studies have described effects of coal heating fuel on children's health in a Western country. Breast-feeding may attenuate adverse effects of prenatal and childhood exposures to combustion products.

Air Pollution, Indoor↗
PubMed2006

Social correlates of the chronic stress of perceived racism among Black women.

OBJECTIVES: This study describes the perceptions of racism, passive and active responses to this psychosocial stressor, and it examines socioeconomic correlates of perceived racism in an economically diverse population of Black women. METHODS: The Telephone-Administered Perceived Racism Scale was administered to 476 Black women, aged 36 to 53 years, who were randomly selected from a large health plan. RESULTS: The percentage of respondents who reported personally experiencing racism in the past five years ranged from 66% to 93%, depending on the specific item asked. When respondents were asked about racism toward Blacks as a group, perceptions of racism were even higher. For example, 68% "agreed" or "strongly agreed" that they had personally experienced being followed or watched while shopping because of their race, and 93% reported that Blacks in general experience this form of discrimination. Strong emotional responses to racism were often reported, and though more respondents (41%) reported experiencing very strong active emotions including anger, a substantial group (16%) reported experiencing very strong passive emotions such as powerlessness. Higher education was associated with higher perceived racism, while growing up in a middle-income or well-off family was associated with lower perceived racism and reduced likelihood of passive responses to racism. CONCLUSIONS: The high prevalence of perceived racism in this study population warrants further examination of this stressor as a potential determinant of racial health disparities. Higher education and income do not appear to protect women from experiencing racism and feeling hopeless or powerless in response.

Adult↗
PubMed2005

Choice of exposure scores for categorical regression in meta-analysis: a case study of a common problem.

OBJECTIVE: Reporting categorical relative risk estimates for a series of exposure levels versus a common reference category is a widespread practice. In meta-analysis, categorical regression estimates a dose-response trend from such results. This method requires the assignment of a single score to each exposure category. We examined how closely meta-analytical categorical regression approximates the results of analysis based on the individual-level continuous exposure. METHODS: The analysis included five studies on tea intake and outcomes related to colorectal cancer. In addition, we derived categorical mean and median values from published distributions of tea consumption in similar populations to assign scores to the categories of tea intake when possible. We examined whether these derived mean and median values well approximate the individual-level results. RESULTS: In meta-analytical categorical regression, using the midrange scores approximated the individual-level continuous analyses reasonably well, if the value assigned to the uppermost, open-ended category was at least as high as the lower bound plus the width of the second-highest category. Categorical mean values derived from the published distributions of regular tea (in the US) and green tea (in Japan) well approximated the slope obtained from individual-level analysis. CONCLUSION: Publication of both the categorical and the continuous estimates of effect in primary studies, with their standard errors, can enhance the quality of meta-analysis, as well as providing intrinsically valuable information on dose-response.

Age Distribution↗
PubMed2005

In utero polychlorinated biphenyl exposures in relation to fetal and early childhood growth.

BACKGROUND: Polychlorinated biphenyls (PCBs) are industrial chemicals that were used widely for approximately 50 years. Now banned, they are still ubiquitous because of their persistence in the environment, the food chain, and human fatty tissue. High in utero exposures cause developmental deficits accompanied by growth retardation. Studies examining intrauterine growth at lower exposures have been inconsistent, with most such investigations having relied on surrogate exposure indicators such as consumption of fish from contaminated bodies of water. METHODS: In the 1960s, serum specimens were collected from pregnant women participating in the Child Health and Development Study in the San Francisco Bay Area. The women were interviewed and their serum samples stored at -20 degrees C. At 5 years of age, detailed anthropometric measurements were made on children born in the years 1964-1967. We measured PCBs in specimens from 399 mothers using gas chromatography/electron capture detection. We conducted multiple linear regression to examine the relationship between these organochlorine concentrations and both intrauterine and 5-year growth, with adjustment for medical, lifestyle, sociodemographic, and specimen characteristics. RESULTS: In male infants, higher total in utero PCB exposure was associated with reduced birth weight, head circumference, and weight-for-gestational age. An increase from the 10th to 90th percentile in total PCBs was related to 290 g lower birth weight, a 0.7-cm decrease in head circumference, and for weight for gestational age, a reduction in z-score of 0.6. In girls, smaller head circumference and shorter gestations were observed. In contrast, prenatal PCBs were associated with greater growth in 5-year-old girls, with no apparent effect in 5-year-old boys. CONCLUSIONS: Maternally mediated exposure to PCBs may be detrimental to fetal growth, particularly in boys. These effects apparently are not persistent. Interpretation of greater childhood growth of girls is unclear.

Adult↗
PubMed2005

Air pollution and lymphocyte phenotype proportions in cord blood.

Effects of air pollution on morbidity and mortality may be mediated by alterations in immune competence. In this study we examined short-term associations of air pollution exposures with lymphocyte immunophenotypes in cord blood among 1,397 deliveries in two districts of the Czech Republic. We measured fine particulate matter < 2.5 microm in diameter (PM2.5) and 12 polycyclic aromatic hydrocarbons (PAHs) in 24-hr samples collected by versatile air pollution samplers. Cord blood samples were analyzed using a FACSort flow cytometer to determine phenotypes of CD3+ T-lymphocytes and their subsets CD4+ and CD8+, CD19+ B-lymphocytes, and natural killer cells. The mothers were interviewed regarding sociodemographic and lifestyle factors, and medical records were abstracted for obstetric, labor and delivery characteristics. During the period 1994 to 1998, the mean daily ambient concentration of PM2.5 was 24.8 microg/m3 and that of PAHs was 63.5 ng/m3. In multiple linear regression models adjusted for temperature, season, and other covariates, average PAH or PM2.5 levels during the 14 days before birth were associated with decreases in T-lymphocyte phenotype fractions (i.e., CD3+ CD4+, and CD8+), and a clear increase in the B-lymphocyte (CD19+) fraction. For a 100-ng/m3 increase in PAHs, which represented approximately two standard deviations, the percentage decrease was -3.3% [95% confidence interval (CI), -5.6 to -1.0%] for CD3+, -3.1% (95% CI, -4.9 to -1.3%) for CD4+, and -1.0% (95% CI, -1.8 to -0.2%) for CD8+ cells. The corresponding increase in the CD19+ cell proportion was 1.7% (95% CI, 0.4 to 3.0%). Associations were similar but slightly weaker for PM2.5. Ambient air pollution may influence the relative distribution of lymphocyte immunophenotypes of the fetus.

Air Pollution↗
PubMed2004

A simple approach to performing quantitative cancer risk assessment using published results from occupational epidemiology studies.

Quantitative risk assessment provides formalized scientific input for setting occupational and environmental standards for potentially toxic exposures. We describe the methods to perform quantitative cancer risk assessment based on published epidemiological literature using a hand calculator or spreadsheet. These methods are illustrated for some suspected or known human carcinogens, including perchloroethylene, formaldehyde, benzene and nickel. The approach to cancer risk assessment presented here may prove useful for those without access to original data from epidemiologic studies. The methods described should facilitate the use of published epidemiological data in the estimation of cancer risk in the general or working population.

Humans↗
PubMed2004

Adult hemoglobin levels at birth and risk of sudden infant death syndrome.

BACKGROUND: During the final weeks of gestation, infants normally begin a transition from the production of fetal to adult hemoglobin. Delayed or faulty transition to the production of adult hemoglobin might play a role in the etiology of sudden infant death syndrome (SIDS). OBJECTIVE: To examine the association between adult hemoglobin levels measured at birth and the subsequent risk of SIDS. DESIGN AND SETTING: Cohort study of all infants born in California between March 1, 1990, and December 31, 1997, who were enrolled in the state's Newborn Screening Program and followed up during the first year of life to identify deaths attributed to SIDS. PARTICIPANTS: Population-based sample of 3.2 million infants. MAIN OUTCOME MEASURE: Risk of death attributed to SIDS. RESULTS: The study included 2425 infants whose deaths were attributed to SIDS. There was an inverse relationship between adult hemoglobin level, expressed as a percentage of total hemoglobin, and the subsequent incidence of SIDS. After adjustment for infant sex, race/ethnicity, length of gestation, maternal age, maternal education, maternal smoking, intrauterine growth restriction, and preeclampsia/eclampsia, the relative risks of SIDS for infants in the lower 4 quintiles of adult hemoglobin level were, in descending order, 1.12 (95% confidence interval [CI], 0.96-1.32), 1.38 (95% CI, 1.19-1.59), 1.55 (95% CI, 1.34-1.80), and 2.15 (95% CI, 1.87-2.47) compared with infants in the highest quintile. CONCLUSIONS: These findings suggest that infants with low levels of adult hemoglobin in the first hours after birth are at elevated risk of SIDS. Delayed maturation in production of adult hemoglobin may play a role in the etiology of some SIDS cases.

California↗
PubMed2004

Bed rest and other determinants of bone loss during pregnancy.

OBJECTIVE: The purpose of this study was to evaluate patterns of bone loss during pregnancy and potential influences. STUDY DESIGN: This was a prospective study of 181 women receiving prenatal care at Magee-Womens Hospital or its auxiliary clinics in Pittsburgh, Pennsylvania, between 1992 and 1995. Bone mineral density was measured at approximately 16 and 36 weeks' gestation. RESULTS: Trabecular, but not cortical, bone loss occurred during pregnancy. Mean ultra-distal bone mineral density loss was 1.9% (95% CI 1.2-2.5) during the 20-week period. Women prescribed bed rest had an adjusted mean loss of 4.6% compared with 1.5% for women not prescribed bed rest ( P = .001) and 6-fold higher odds ( P = .001) of bone loss > or =5% during the 20-week period. Nulliparity, calcium intake < 2 000 mg/day, low weight gain, and maternal age < 21 or >30 years were more modestly associated with greater bone loss. CONCLUSION: Substantial trabecular bone loss may occur during pregnancy, particularly in women prescribed bed rest. Study of postpartum bone recovery in such women is needed.

Adolescent↗