Association of Parental Preconception Exposure to Phthalates and Phthalate Substitutes With Preterm Birth.

Importance: Although phthalate exposure during pregnancy has been associated with preterm birth, the association of preconception exposure in either parent with preterm birth constitutes a knowledge gap. Objective: To examine the association of paternal and maternal preconception urinary concentrations of biomarkers of phthalates and phthalate substitutes with singleton preterm birth. Design, Setting, and Participants: This study, conducted at an academic fertility center in Boston, Massachusetts, included a prospective preconception cohort of subfertile couples comprising 419 mothers and 229 fathers and their 420 live-born singleton offspring born between January 1, 2005, and December 31, 2018. Statistical analysis was performed from August 1 to October 31, 2019. Exposures: Urinary concentrations of metabolites of phthalates and phthalate substitutes obtained before conception. Main Outcomes and Measures: Gestational age was abstracted from delivery records and validated using the American College of Obstetricians and Gynecologists guidelines for births after medically assisted reproduction. The risk ratio (RR) of preterm birth (live birth before 37 completed weeks' gestation) was estimated in association with urinary concentrations of 11 individual phthalate metabolites, the molar sum of 4 di-(2-ethylhexyl) phthalate (ΣDEHP) metabolites, and 2 metabolites of 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH, a nonphthalate plasticizer substitute) using modified Poisson regression models adjusted for covariates. Results: The mean (SD) age of the 419 mothers was 34.7 (4.0) years, the mean (SD) age of the 229 fathers was 36.0 (4.5) years, and the mean (SD) gestational age of the 420 singleton children (217 boys) was 39.3 (1.7) weeks, with 34 (8%) born preterm. In adjusted models, maternal preconception ΣDEHP concentrations (RR, 1.50; 95% CI, 1.09-2.06; P = .01) and cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester (MHiNCH, a metabolite of DINCH) concentrations (RR, 1.70; 95% CI, 0.89-3.24; P = .11) were associated with an increased risk of preterm birth. After additional adjustment for prenatal ΣDEHP or MHiNCH concentrations, the association of maternal preconception exposure to ΣDEHP and preterm birth remained robust (RR, 1.69; 95% CI, 1.17-2.44; P = .006), while the association of maternal preconception exposure to MHiNCH and preterm birth was attenuated (RR, 1.17; 95% CI, 0.49-2.81; P = .72). The remaining urinary metabolites examined in either parent showed no association with preterm birth. Conclusions and Relevance: In this prospective cohort of subfertile couples, maternal preconception exposure to ΣDEHP metabolites was associated with an increased risk of preterm birth. The results suggest that female exposure to select phthalate plasticizers during the preconception period may be a potential risk factor for adverse pregnancy outcomes, which may need to be considered in preconception care strategies.

Simulations and directed acyclic graphs explained why assortative mating biases the prenatal negative control design.

OBJECTIVE: The negative control design can be used to provide evidence for whether a prenatal exposure-outcome association occurs by in utero mechanisms. Assortative mating has been suggested to influence results from negative control designs, although how and why has not yet been adequately explained. We aimed to explain why mutual adjustment of maternal and paternal exposure in regression models can account for assortative mating. STUDY DESIGN AND SETTING: We used directed acyclic graphs to show how bias can occur when modeling maternal and paternal effects separately. We empirically tested our claims using a simulation study. We investigated how increasing assortative mating influences the bias of effect estimates obtained from models that do and do not use a mutual adjustment strategy. RESULTS: In models without mutual adjustment, increasing assortative mating led to increased bias in effect estimates. The maternal and paternal effect estimates were biased by each other, making the difference between them smaller than the true difference. Mutually adjusted models did not suffer from such bias. CONCLUSIONS: Mutual adjustment for maternal and paternal exposure prevents bias from assortative mating influencing the conclusions of a negative control design. We further discuss issues that mutual adjustment may not be able to resolve.

Parental occupational exposure to low-frequency magnetic fields and risk of leukaemia in the offspring: findings from the Childhood Leukaemia International Consortium (CLIC).

OBJECTIVES: Previously published studies on parental occupational exposure to extremely low-frequency magnetic fields (ELF-MF) and risk of acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in their offspring were inconsistent. We therefore evaluated this question within the Childhood Leukemia International Consortium. METHODS: We pooled 11 case-control studies including 9723 childhood leukaemia cases and 17 099 controls. Parental occupational ELF-MF exposure was estimated by linking jobs to an ELF-MF job-exposure matrix (JEM). Logistic regression models were used to estimate ORs and 95% CIs in pooled analyses and meta-analyses. RESULTS: ORs from pooled analyses for paternal ELF-MF exposure >0.2 microtesla (µT) at conception were 1.04 (95% CI 0.95 to 1.13) for ALL and 1.06 (95% CI 0.87 to 1.29) for AML, compared with ≤0.2 µT. Corresponding ORs for maternal ELF-MF exposure during pregnancy were 1.00 (95% CI 0.89 to 1.12) for ALL and 0.85 (95% CI 0.61 to 1.16) for AML. No trends of increasing ORs with increasing exposure level were evident. Furthermore, no associations were observed in the meta-analyses. CONCLUSIONS: In this large international dataset applying a comprehensive quantitative JEM, we did not find any associations between parental occupational ELF-MF exposure and childhood leukaemia.

Case-control study of paternal occupational exposures and childhood lymphoma in Great Britain, 1962-2010.

BACKGROUND: This nationwide study investigates associations between paternal occupational exposure and childhood lymphoma. METHODS: The UK National Registry of Childhood Tumours provided cases of childhood lymphoma born and diagnosed in Great Britain 1962-2010. Control births, unaffected by childhood cancer, were matched on sex, birth period and birth registration sub-district. Fathers' occupations were assigned to one or more of 33 exposure groups and also coded for occupational social class. RESULTS: We analysed 5033 childhood lymphoma cases and 4990 controls. Total lymphoma and the subgroups Hodgkin, Burkitt and non-Hodgkin lymphoma were considered separately. No one exposure was significantly associated with increased risk within all subgroups and for total lymphoma. However, exposure to "ceramics and glass" was significantly associated with increased risk of total lymphoma, Hodgkin and non-Hodgkin lymphoma. Paternal lead exposure was associated with Burkitt lymphoma and exposure to metal fumes was associated with Hodgkin lymphoma. CONCLUSIONS: This study provides no support for previous suggestions of an association between childhood lymphoma and paternal occupational exposure to pesticides, solvents/hydrocarbons or infections potentially transmitted by father's social contacts. An association with exposure to "ceramics and glass" was noted for the two major lymphoma subtypes together comprising 80% of total lymphoma.

Risk of selected childhood cancers and parental employment in painting and printing industries: A register-based case‒control study in Denmark 1968-2015.

Objectives Parental exposures and offspring's risk of cancer have been studied with inconsistent results. We investigated parental employment in painting and printing industries and risk of childhood leukemia, central nervous system (CNS) cancers, and prenatal cancers (acute lymphoblastic leukemia, Wilms tumor, medulloblastoma, neuroblastoma, retinoblastoma, and hepatoblastoma). Methods Using Danish registries, children aged ≤19 years diagnosed from 1968-2015 with leukemia (N=1999), CNS cancers (N=1111) or prenatal cancers (N=2704) were linked to parents and their employment history one year before birth to birth for fathers, and one year before birth to one year after for mothers. Twenty randomly selected controls per case were matched by age and sex. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using conditional logistic regression. Results For fathers, we found increased risks for acute myeloid leukemia (AML) consistent in painting (OR 2.26, 95% CI 1.07-4.80) and printing industries (OR 2.43, 95% CI 0.94-6.23) and these industries combined (OR 2.10, 95% CI 1.14-3.87). For mothers, increased risks of CNS cancers were found for painting industries (OR 2.34, 95% CI 1.10-4.95) and painting and printing combined (OR 1.97, 95% CI 1.08-3.64). For fathers working in combined industries, the OR for CNS was increased (OR 1.54, 95% CI 1.02-2.31), most prominently in printing industries (OR 2.09, 95% CI 1.17-3.75). Conclusion We observed increased risks of CNS tumors in offspring after parental employment in painting and printing industries. Children of fathers employed in painting and printing industries had a two-fold increase in AML.

Pregnancy Outcomes Reported During the 13-Year TREAT Registry: A Descriptive Report.

OBJECTIVES: We described pregnancy outcomes in Crohn's disease (CD) patients enrolled in the TREAT Registry who received infliximab before, or during pregnancy and those not treated with infliximab or any biologic agent. METHODS: In the TREAT Registry (1999-2012), pregnancy outcomes were analyzed from maternal and paternal patients exposed to infliximab ≤365 days (gestational exposure), >365 days (pre-gestational exposure) of pregnancy outcome or without infliximab exposure (non-biologic exposed). "Healthy infants" were defined as those with no congenital abnormalities, neonatal complications (e.g., jaundice, prematurity, heart murmur, cortical vision/fine motor delay, cardiac failure, hemophilia, or torticollis), prolonged hospitalization, or those who received no special treatment. Disease activity and concomitant medications were also evaluated. RESULTS: Overall, 92.3% (324/351) of pregnancies had known outcomes. The majority of both maternal pregnancies (92.6, 91.2, and 87.8%) and partner outcomes (92.7, 93.8, and 91.7%) resulted in live births of healthy infants across gestational, pre-gestational, and non-biologic exposure groups, respectively. Among these, rates of neonatal complications were low for both maternal (6.2, 7.0, and 8.5%), and partner outcomes (4.9, 0, and 0%) in gestational, pre-gestational, and non-biologic exposure groups, respectively. Among maternal pregnancies, numerically higher rates of spontaneous abortions were observed for the gestational exposure group than for the pre-gestational or non-biologic exposed groups. CONCLUSIONS: The clinical condition of infants born to women with gestational infliximab exposure was similar to those without exposure. Although a lower live birth rate was reported among infliximab-exposed women, these patients had more severe CD and were more likely to have been exposed to immunosuppressives.

Socio-demographic and preconception risk factors in parents of children suffering from congenital cardiopathy. / Factores sociodemográficos y factores de riesgo preconcepcionales en padres y madres de niños con cardiopatías congénitas.

OBJECTIVE: To identify the preconception risk factors in parents of children suffering from congenital cardiopathy. METHOD: A cross-sectional descriptive study, which included parents of children suffering from cardiopathy, attended at consultations in a not-for-profit organization, in order to be diagnosed and referred for heart surgery or to be assessed in postoperative cardiac monitoring. The sample population included 500 people who responded to a survey for the identification of socio-demographic and preconception risk factors. RESULTS: Couples were found with up to 3 cardiac children. Parents with 2 or more children suffering from cardiopathy were classified in the majority as belonging to the middle socioeconomic level and not owning their own house. An association with the number of children with cardiopathy, the educational level of their parents (P=.013), their home area (P=.041) and type of accommodation (P=.045) was found. Regarding the preconception risk factors, there was evidence of statistically significant associations among the number of children with cardiopathy and their exposure to fertilizers (P=.024), their exposure to fuels (P=.025), the use of antihypertensive medication (P=.37), and alcohol consumption (P=.042) and cocaine use (P=.039) by their parents. CONCLUSIONS: The population of parents with a greater number of children suffering from cardiopathy were characterized as having socioeconomic and educational constraints. The preconception risk factors which show an association with the number of children suffering from cardiopathy were characterized as physical and/or chemical environmental risk factors and the consumption of certain psychoactive substances and medication by their parents. It is necessary to analyze each risk factor separately, taking into account the different types of cardiopathy.

Parental Occupational Exposure to Organic Solvents and Testicular Germ Cell Tumors in their Offspring: NORD-TEST Study.

BACKGROUND: Testicular germ cell tumors (TGCT) were suggested to have a prenatal environmentally related origin. The potential endocrine disrupting properties of certain solvents may interfere with the male genital development in utero. OBJECTIVES: We aimed to assess the association between maternal and paternal occupational exposures to organic solvents during the prenatal period and TGCT risk in their offspring. METHODS: This registry-based case control study included TGCT cases aged 14­49 y (n=8,112) diagnosed from 1978 to 2012 in Finland, Norway, and Sweden. Controls (n=26,264) were randomly selected from the central population registries and were individually matched to cases on year and country of birth. Occupational histories of parents prior to the child's birth were extracted from the national censuses. Job codes were converted into solvent exposure using the Nordic job-Nordic Occupational Cancer Study Job-Exposure Matrix. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Overall, no association was found between prenatal maternal exposure to solvents and TGCT risk. In subset analyses using only mothers for whom occupational information was available in the year of or in the year prior to the child's birth, there was an association with maternal exposure to aromatic hydrocarbon solvents (ARHC) (OR=1.53; CI: 1.08, 2.17), driven by exposure to toluene (OR=1.67; CI: 1.02, 2.73). No association was seen for any paternal occupational exposure to solvents with the exception of exposure to perchloroethylene in Finland (OR=2.42; CI: 1.32, 4.41). CONCLUSIONS: This study suggests a modest increase in TGCT risk associated with maternal prenatal exposure to ARHC. https://doi.org/10.1289/EHP864.

Exposure to toxics during pregnancy and childhood and asthma in children: A pilot study.

Environmental factors, pesticides, alcohol and smoking are linked to asthma in children. The association of toxic substances exposure with asthma has not been evaluated. Our objective is to assess such associations among children aged less than 16years old. This is a cross-sectional study, conducted between January and May 2015, using a sample of Lebanese students from private schools in Beirut and Mount Lebanon. Out of 700 distributed questionnaires, 527 (75.2%) were returned to us. Verbal informed consent was also obtained from all parents prior to participating in the study. A significant association was found between waterpipe smoking and diagnosed asthma (p=0.003; ORa=13.25; 95% CI 2.472-71.026). Alcohol during pregnancy, waterpipe smoking during pregnancy and parents respiratory problems significantly increased the risk of respiratory problems by approximately 5 times, 6 times and 2 times respectively (p=0.016; ORa=4.889; 95% CI 1.339-17.844, p=0.021; ORa=6.083; 95% CI 1.314-28.172, p=0.004; ORa=1.748; 95% CI 1.197-2.554 respectively). Waterpipe smoking, alcohol during pregnancy, recurrent otitis and humidity at home seem to be significantly correlated with asthma in children. Spreading awareness by health care professionals is needed to permit a reduction of the prevalence of these allergic diseases, especially asthma, in children.

Impact of maternal and paternal smoking on birth outcomes.

Background: The adverse effects of maternal and paternal smoking on child health have been studied. However, few studies demonstrate the interaction effects of maternal/paternal smoking, and birth outcomes other than birth weight have not been evaluated. The present study examined individual effects of maternal/paternal smoking and their interactions on birth outcomes. Methods: A follow-up hospital-based study from pregnancy to delivery was conducted from 1997 to 2010 with parents and newborn infants who delivered at a large hospital in Hamamatsu, Japan. The relationships between smoking and growth were evaluated with logistic regression. Results: The individual effects of maternal smoking are related to low birth weight (LBW), short birth length and small head circumference. The individual effects of paternal smoking are related to short birth length and small head circumference. In the adjusted model, both parents' smoking showed clear associations with LBW (odds ratio [OR] = 1.64, 95% confidence interval [CI] 1.18-2.27) and short birth length (-1 standard deviation [SD] OR = 1.38, 95% CI 1.07-1.79; -2 SD OR = 2.75, 95% CI 1.84-4.10). Conclusions: Maternal smoking was significantly associated with birth weight and length, but paternal smoking was not. However, if both parents smoked, the risk of shorter birth length increased.

Birth Outcomes in Children Fathered by Men Treated with Anti-TNF-α Agents Before Conception.

OBJECTIVES: The safety of paternal use of anti-tumor necrosis factor-α (TNF-α) agents immediately prior to conception is practically unknown. On the basis of nationwide data from Danish health registries, we examined the association between paternal use of anti-TNF-α agents within 3 months before conception and adverse birth outcomes. METHODS: This nationwide cohort study is based on data from all women who had a live born singleton child in Denmark from 1 January 2007 through 2013. Children fathered by men treated with anti-TNF-α agents within three months before conception constituted the exposed cohort (N=372), and children fathered by men not treated before conception constituted the unexposed cohort (N=399,498). The outcomes were congenital abnormalities (CAs), preterm birth, and small for gestational age (SGA). We adjusted for multiple covariates, and considered paternal underlying disease and concomitant medication. RESULTS: The adjusted risks of CAs and preterm birth were close to unity, and the adjusted odds ratio (OR) for SGA was 1.70 (95% confidence interval (CI): 0.94-3.09). Restricting our analysis to fathers with inflammatory bowel disease, we found no increased risk of CAs or SGA, and the adjusted OR for pretem birth was 1.42 (95% CI: 0.52-3.86). Restricting our analysis to fathers with rheumatologic/dermatological diseases, we found no increased risk of CAs or preterm birth, and the adjusted OR for SGA was 1.70 (95% CI: 0.74-3.89). CONCLUSIONS: Our results are overall reassuring regarding the safety of paternal preconceptional use of anti-TNF-α agents. The result regarding SGA should, however, be interpreted with caution as we found an increased risk, although not significantly increased.

Parental occupational exposures to endocrine disruptors and the risk of simple isolated congenital heart defects.

This study aims to explore the associations between parental occupational exposures to endocrine disruptors (EDs) and simple isolated congenital heart defects (CHDs). A case-control study with standardized data collection involving 761 children with isolated CHDs and 609 children without any congenital malformations was conducted in Sichuan Province of China from March in 2012 to August in 2013. An adjusted job exposure matrix was used for occupational EDs exposure assessment. Logistic regression analysis was performed to assess the associations between parental occupational EDs exposures and CHDs. Maternal age at births, maternal education level, gravity, parity, induced abortion, folic acid use, medication use, drinking capacity and area of residence periconceptionally were selected as confounding factors for mothers. For fathers, we selected the following confounding factors: paternal education level, smoking, drinking frequencies and drinking capacity periconceptionally. Maternal occupational exposures to phthalates are associated with perimembranous ventricular septal defect (PmVSD) (P = 0.001, adjusted OR 3.7, 95 % CI 1.7-8.0), patent ductus arteriosus (PDA) (P = 0.002, adjusted OR 3.8, 95 % CI 1.6-8.9), secundum atrial septal defect (s-ASD) (P = 0.008, adjusted OR 3.5, 95 % CI 1.4-8.7) and pulmonary valve stenosis (PS) (P = 0.035, adjusted OR 4.2, 95 % CI 1.1-16.0), to alkylphenolic compounds and PmVSD (P = 0.003, adjusted OR 2.2, 95 % CI 1.3-3.6), PDA (P = 0.005, adjusted OR 2.0, 95 % CI 1.1-3.5) and PS (P = 0.004, adjusted OR 3.8, 95 % CI 1.5-9.4), to heavy metals with PmVSD (P = 0.003, adjusted OR 7.3, 95 % CI 2.0-27.6) and s-ASD (P = 0.034, adjusted OR 6.5, 95 % CI 1.1-36.7). Paternal occupational exposures to phthalates are associated with PmVSD (P = 0.035, adjusted OR 1.6, 95 % CI 1.0-2.4) and PS (P = 0.026, adjusted OR 2.4, 95 % CI 1.1-5.2), to alkylphenolic compounds (P = 0.027, adjusted OR 1.5, 95 % CI 1.0-2.2) with PmVSD. In conclusion, parental occupational exposures to some specific EDs, in particular phthalates and alkylphenolic compounds, are associated with an increased risk of some CHD phenotypes. However, the findings need to be considered more circumspectly regarding a crude measure of exposure probabilities and small numbers.

[SYNERGISM OF PRECONCEPTIVE RADIATION EXPOSURE AND PARENTS' ONCO-PATHOLOGY IN THE RISE OF CARCINOGENIC RISK IN THE OFFSPRINGS OF PROFESSIONAL EMPLOYEES].

The problem of carcinogenic risk in offsprings of individuals exposed to radiation is challenging and insufficiently studied. In that there are no evaluations of the interaction between radiation and non-radiation factors. The aim of the study was the analysis of interaction of preconceptive radiation exposure and parents' onco-pathology in cancer mortality in offsprings (F1) of workers (fathers) of the Mayak Production Association exposed to a wide range of doses of radiation over a year prior conception. The number of offspring is 8191 individuals (4180 men and 4011 women). The analysis was performed with the use of fourfold table and eightfold tables. The interaction offactors was estimated on the base of the additive and multiplicative models. The studied factors were independent. The odds ratio (OR) of cancer mortality in the offspring with parents' oncopathology (1.43) was insignificant. OR of cancer mortality in preconceptive radiation exposure in a dose over 110 mGy and without parents' onco-pathology was 2.61 (1.52-4.49), and in their combination--3.86 (1.93-7.71). Index of synergism of preconceptive radiation exposure and parents' onco-patholog in the rise of carcinogenic risk in the offspring was 1.34 and the character of their interaction was multiplicative. Thus, for the first time there was established the interaction between radiation and non-radiation factors in the synergism sort in the increase of carcinogenic risk in the offspring of people exposed to radiation.

Germline minisatellite mutations in workers occupationally exposed to radiation at the Sellafield nuclear facility.

Germline minisatellite mutation rates were investigated in male workers occupationally exposed to radiation at the Sellafield nuclear facility. DNA samples from 160 families with 255 offspring were analysed for mutations at eight hypervariable minisatellite loci (B6.7, CEB1, CEB15, CEB25, CEB36, MS1, MS31, MS32) by Southern hybridisation. No significant difference was observed between the paternal mutation rate of 5.0% (37 mutations in 736 alleles) for control fathers with a mean preconceptional testicular dose of 9 mSv and that of 5.8% (66 in 1137 alleles) for exposed fathers with a mean preconceptional testicular dose of 194 mSv. Subgrouping the exposed fathers into two dose groups with means of 111 mSv and 274 mSv revealed paternal mutation rates of 6.0% (32 mutations in 536 alleles) and 5.7% (34 mutations in 601 alleles), respectively, neither of which was significantly different in comparisons with the rate for the control fathers. Maternal mutation rates of 1.6% (12 mutations in 742 alleles) for the partners of control fathers and 1.7% (19 mutations in 1133 alleles) for partners of exposed fathers were not significantly different. This study provides evidence that paternal preconceptional occupational radiation exposure does not increase the germline minisatellite mutation rate and therefore refutes suggestions that such exposure could result in a destabilisation of the germline that can be passed on to future generations.

Risk of congenital malformations among children of construction painters in Denmark: a nationwide cohort study.

OBJECTIVES: Painters' occupational exposure is classified as a group 1 carcinogen by the International Agency for Research on Cancer (IARC). Previous studies have shown increased risk of congenital malformations among children of women exposed to organic solvents and paint emissions during pregnancy. In Denmark, women comprise half of those enrolled in vocational paint training. We investigated the association between maternal and paternal occupational painting, respectively, and the risk of congenital malformations among children. METHODS: National register data were used to link childbirths, malformations, and parental occupation. The cohort included >1,300,000 children born to occupationally active women in Denmark 1980-2010. Cases were hospital-diagnosed with malformations within the first year of life. Odds ratios (OR) with 95% confidence intervals (95% CI) were estimated using multiple logistic regression with adjustment for potential confounders. RESULTS: Among 3444 children of female construction painters, we found no increased risk of malformations overall (126 cases, OR 0.88, 95% CI 0.74-1.05) or in organ-specific subgroups compared to children of women in all other occupations (55 045 cases). Sensitivity analyses restricted to severe malformations, children of maternal painters with ≥2 years of pre-pregnancy exposure, and firstborn children, and analyses with maternal healthcare assistants and kitchen workers as reference supported the main results. Also, no associations were found when including diagnoses within the first 10 years of life, when stratifying by maternal age, birth year, and sex, or for paternal construction painters. CONCLUSIONS: This nationwide cohort study is reassuring with no indications of increased risk of congenital malformations among children of male or of female construction painters.

Parental occupational paint exposure and risk of childhood leukemia in the offspring: findings from the Childhood Leukemia International Consortium.

PURPOSE: It has been suggested that parental occupational paint exposure around the time of conception or pregnancy increases the risk of childhood leukemia in the offspring. METHODS: We obtained individual level data from 13 case-control studies participating in the Childhood Leukemia International Consortium. Occupational data were harmonized to a compatible format. Meta-analyses of study-specific odds ratios (ORs) were undertaken, as well as pooled analyses of individual data using unconditional logistic regression. RESULTS: Using individual data from fathers of 8,185 cases and 14,210 controls, the pooled OR for paternal exposure around conception and risk of acute lymphoblastic leukemia (ALL) was 0.93 [95% confidence interval (CI) 0.76, 1.14]. Analysis of data from 8,156 ALL case mothers and 14,568 control mothers produced a pooled OR of 0.81 (95% CI 0.39, 1.68) for exposure during pregnancy. For acute myeloid leukemia (AML), the pooled ORs for paternal and maternal exposure were 0.96 (95% CI 0.65, 1.41) and 1.31 (95% CI 0.38, 4.47), respectively, based on data from 1,231 case and 11,392 control fathers and 1,329 case and 12,141 control mothers. Heterogeneity among the individual studies ranged from low to modest. CONCLUSIONS: Null findings for paternal exposure for both ALL and AML are consistent with previous reports. Despite the large sample size, results for maternal exposure to paints in pregnancy were based on small numbers of exposed. Overall, we found no evidence that parental occupational exposure to paints increases the risk of leukemia in the offspring, but further data on home exposure are needed.

A meta-analysis of parental smoking and the risk of childhood brain tumors.

OBJECTIVE: Previous studies regarding the association between parental smoking and the risk of childhood brain tumors (CBT) have reported inconsistent results. We performed a meta-analysis to summarize evidence on this association and to quantify the potential dose-response relationship. METHODS: A systematic literature search was conducted in the Medline and Embase databases. The summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated. Dose-response meta-analysis was also performed for studies that reported categorical risk estimates for a series of smoking exposure levels. RESULTS: A total of 17 studies fulfilled the inclusion criteria. In the meta-analyses, the summary RRs (95% CIs) of CBT for maternal smoking during pregnancy, paternal smoking during pregnancy, maternal smoking before pregnancy, and paternal smoking before pregnancy were 0.96 (0.86-1.07), 1.09 (0.97-1.22), 0.93 (0.85-1.00), and 1.09 (1.00-1.20), respectively. Dose-response meta-analysis also showed no significant association between parental smoking and the risk of CBT. CONCLUSIONS: Findings from our meta-analysis indicate that parental smoking may not be associated with a risk of CBT.

Childhood and parental diagnostic radiological procedures and risk of childhood brain tumors.

PURPOSE: Childhood brain tumors (CBT) are the second most common type of childhood cancer and the leading cause of childhood cancer mortality. Few causes of CBT are known, but parental, fetal, and early life exposures are likely to be important given the early age at diagnosis of many cases. We aimed to investigate whether parents' diagnostic radiological procedures before conception, in the mother during pregnancy or the child's procedures were associated with an increased risk of CBT. METHODS: This population-based case-control study was conducted between 2005 and 2010. Cases were identified through all ten Australian pediatric oncology centers, and controls via nationwide random-digit dialing; frequency-matched to cases on age, sex and state of residence. Information on radiological exposures in the time periods of interest was obtained for 306 case and 950 control families through mailed questionnaires. Analysis used unconditional logistic regression, adjusting for matching variables and potential confounders. RESULTS: We found no evidence of positive associations between risk of CBT overall and childhood or parental pre-pregnancy radiological procedures. Increased ORs for high-grade gliomas associated with childhood radiological procedures were based on small numbers and may be due to chance. CONCLUSIONS: Given the evidence for an increased risk of CBT in cohort studies of computed tomography (CT) in childhood, the lack of such an association in our study may be due to the reduced intensity of CTs after 2001. Future research to investigate the safety of fetal exposure to more intense procedures like CT scans is needed.

Maternal and perinatal factors associated with subsequent meningococcal, Haemophilus or enteroviral meningitis in children: database study.

We used a database of 248 659 births, with follow-up to subsequent disease, in the Oxford record linkage archive (1979-1999) to study the influence of family, maternal, and perinatal factors on subsequent hospital admission for meningococcal, Haemophilus, and enteroviral meningitis in the children. In this summary, we report key findings that were significant in multivariate analysis. Meningococcal meningitis was significantly associated with maternal smoking [odds ratio (OR) 2·1, 95% confidence interval (CI) 1·2-3·7]. Haemophilus meningitis was associated with having older siblings (e.g. second child compared to first-born, OR 3·3, 95% CI 2·0-5·6). Enteroviral meningitis was associated with low birth weight (OR 2·2, 95% CI 1·3-3·6) and male sex (OR 1·7, 95% CI 1·2-2·3). The mothers of six of the 312 children with enteroviral meningitis had previously had enteroviral meningitis themselves. We concluded that several maternal characteristics influence the risk of these types of meningitis.

[On the problem of permissible levels of emergency and subsequent occupational radiation exposure for people of reproductive age].

The results of studies of indices of reproductive function in 3 groups of males examined accordingly to an unified method: Group 1 - The staff of the Kalinin Nuclear Power Plant (KNPP) and the Smolensk Nuclear Power Plant (SNPP), who worked for liquidation of consequences of the accident (LCA) in 1986-87 at the Chernobyl Nuclear Power Plant (ChNPP), group 2 - the staff of the KNPP and the SNPP who did not work for LCA in ChNPP and the group 3 - the liquidators of the accident at ChNPP who were not included in the staff but are registered in the register of LPA participants in the Ryazan region are presented. The occurrence of congenital malformations (CM) and intrauterine growth retardation (IUGR) in infants, indices of unfavourable outcomes of pregnancy (UOP) in the families of males, describing the possible radiation-induced genetic effects in male germ cells was evaluated It was made a conclusion that the given in NRB-99/2009 constraints for emergency and subsequent occupational radiation exposures of males fail to provide protection from genetic effects in the offspring. The necessity to increase the duration of the protected reproductive period in males, on which there are extended restrictions for occupational and emergency radiation exposures from 30 years of age, as it is now accepted to the age of 35 years is demonstrated.