Maternal alcohol and coffee drinking, parental smoking and childhood leukaemia: a French population-based case-control study

We investigated the role of maternal alcohol and coffee drinking during pregnancy and that of parental smoking in the aetiology of childhood leukaemia. A French, population-based, case-control study was conducted, comparing 472 [407 acute lymphoblastic leukaemia (ALL) and 62 acute myeloblastic leukaemia] cases of childhood acute leukaemia (AL) and 567 population controls, frequency-matched with cases on age, gender and region of residence. Both case and control mothers filled in a comprehensive self-administered standardised questionnaire, eliciting detailed data on maternal alcohol and coffee consumption during pregnancy and parental smoking before, during and after pregnancy. Maternal alcohol consumption of more than 1 drink per day was related to ALL (OR = 2.8 [95% CI 1.8, 5.9]). While maternal coffee consumption was not significantly related to AL (OR = 1.4 [95% CI 0.9, 2.3]), highest intake of coffee (more than 3 cups per day) during pregnancy was associated with AL in children whose mothers were non-smokers (OR = 1.9 [95% CI 1.0, 3.5]). No association with parental smoking, either maternal or paternal, was observed with AL. The present results suggest a possible role of the highest consumption of alcohol by the mother during pregnancy in the aetiology of childhood AL.     

Maternal prenatal cigarette, alcohol and illicit drug use and risk of infant leukaemia: a report from the Children's Oncology Group

Several case-control studies have evaluated associations between maternal smoking, alcohol consumption and illicit drug use during pregnancy and risk of childhood leukaemia. Few studies have specifically focused on infants (<1 year) with leukaemia, a group that is biologically and clinically distinct from older children. We present data from a Children's Oncology Group case-control study of 443 infants diagnosed with acute leukaemia [including acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML)] between 1996 and 2006 and 324 population controls. Mothers were queried about their cigarette, alcohol and illicit drug use 1 year before and throughout pregnancy. Odds ratios (ORs) and 95% confidence intervals [CI] were calculated using adjusted unconditional logistic regression models. Maternal smoking (>1 cigarette/day) and illicit drug use (any amount) before and/or during pregnancy were not significantly associated with infant leukaemia. Alcohol use (>1 drink/week) during pregnancy was inversely associated with infant leukaemia overall [OR = 0.64; 95% CI 0.43, 0.94], AML [OR = 0.49; 95% CI 0.28, 0.87], and leukaemia with mixed lineage leukaemia gene rearrangements ('MLL+') [OR = 0.59; 95% CI 0.36, 0.97]. While our results agree with the fairly consistent evidence that maternal cigarette smoking is not associated with childhood leukaemia, the data regarding alcohol and illicit drug use are not consistent with prior reports and are difficult to interpret. It is possible that unhealthy maternal behaviours during pregnancy, some of which carry potential legal consequences, may not be adequately measured using only self-report. Future case-control studies of childhood leukaemia that pursue these exposures may benefit from incorporation of validated instruments and/or biomarkers when feasible.     

Maternal asthma and risk of preterm delivery

PURPOSE: We studied the relation between maternal history of asthma and preterm delivery. METHODS: The 312 preterm delivery cases, studied in aggregate, and in subgroups (spontaneous preterm labor, preterm premature rupture of membranes, medically induced preterm delivery), were compared with 424 randomly selected women who delivered at term. Maternal medical records provided information on maternal lifetime asthma status, pregnancy outcome, and sociodemographic characteristics. Using multivariate logistic regression, we derived maximum likelihood estimates of adjusted odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Maternal history of asthma was associated with an increased risk of preterm delivery overall (OR = 2.37; 95% CI 1.15-4.88). Analyses of preterm delivery sub-groups indicated that maternal history of asthma was associated with at least a doubling in risk of spontaneous preterm labor (OR = 2.35; 95% CI 0.84-6.58) and medically induced preterm delivery (OR = 2.69; 95% CI 1.11-6.53), though only the latter approached statistical significance. There was some evidence of a modest association between maternal asthma and risk of preterm premature rupture of membranes (OR = 1.63; 95% CI 0.50-5.33). CONCLUSIONS: These results support the hypothesis that maternal asthma is associated with an increased risk of preterm labor and delivery.     

Maternal exposure to occupational solvents and childhood leukemia

Many organic solvents are considered probable carcinogens. We carried out a population-based case-control study including 790 incident cases of childhood acute lymphoblastic leukemia and as many healthy controls, matched on age and sex. Maternal occupational exposure to solvents before and during pregnancy was estimated using the expert method, which involves chemists coding each individual's job for specific contaminants. Home exposure to solvents was also evaluated. The frequency of exposure to specific agents or mixtures was generally low. Results were generally similar for the period ranging from 2 years before pregnancy up to birth and for the pregnancy period alone. For the former period, the odds ratio (OR), adjusted for maternal age and sex, for any exposure to all solvents together was 1.11 [95% confidence interval (CI), 0.88-1.40]. Increased risks were observed for specific exposures, such as to 1,1,1-trichloroethane (OR = 7.55; 95% CI, 0.92-61.97), toluene (OR = 1.88; 95% CI, 1.01-3.47), and mineral spirits (OR = 1.82; 95% CI, 1.05-3.14). There were stronger indications of moderately increased risks associated with exposure to alkanes (C5-C17; OR = 1.78; 95% CI, 1.11-2.86) and mononuclear aromatic hydrocarbons (OR = 1.64; 95% CI, 1.12-2.41). Risk did not increase with increasing exposure, except for alkanes, where a significant trend (p = 0.04) was observed. Home exposure was not associated with increased risk. Using an elaborate exposure coding method, this study shows that maternal exposure to solvents in the workplace does not seem to play a major role in childhood leukemia.     

Parental smoking and the risk of childhood leukemia

Cigarette smoke has been linked to adult myeloid leukemia; however, the association between parental smoking and childhood leukemia remains unclear. Parental smoking and the risk of childhood leukemia were examined in the Northern California Childhood Leukemia Study, a case-control study, between 1995 and 2002. The present analysis included 327 acute childhood leukemia cases (281 acute lymphoblastic leukemia (ALL) and 46 acute myeloid leukemia (AML)) and 416 controls matched on age, sex, maternal race, and Hispanic ethnicity. Maternal smoking was not associated with an increased risk of either ALL or AML. Paternal preconception smoking was significantly associated with an increased risk of AML (odds ratio = 3.84, 95% confidence interval: 1.04, 14.17); an increased risk for ALL was suggestive for paternal preconception smoking (odds ratio = 1.32, 95% confidence interval: 0.86, 2.04). Greater risks of ALL were observed compared with the risk associated with paternal preconception smoking alone, when paternal preconception smoking was combined with maternal postnatal smoking (p(interaction) = 0.004) or postnatal passive smoking exposure (p(interaction) = 0.004). These results strongly suggest that exposure to paternal preconception smoking alone or in combination with postnatal passive smoking may be important in the risk of childhood leukemia.     

In Utero Pesticide Exposure and Leukemia in Brazilian Children < 2 Years of Age

Background: An association between pesticide exposure and cancer has been suggested. Infant leukemia is a rare neoplasm and its association with maternal pesticide exposure has been poorly explored.Objectives: We investigated the association between pesticide exposure during pregnancy and leukemia in children < 2 years of age.Methods: A hospital-based case–control study was carried out in 13 Brazilian states during 1999–2007. Mothers of 252 cases and those of 423 controls were interviewed. Information on pesticide exposures 3 months before pregnancy, throughout pregnancy, and during breastfeeding was obtained. Unconditional logistic regression was used to estimate adjusted odds ratios (aORs) for associations between pesticide exposures and leukemia.Results: Associations with ever use of pesticides during pregnancy were observed for acute lymphoid leukemia (ALL) (aOR = 2.10; 95% CI: 1.14, 3.86) and acute myeloid leukemia (AML) (aOR = 5.01; 95% CI: 1.97, 12.7) in children 0–11 months of age, and with ALL (aOR = 1.88; 95% CI: 1.05, 5.23) at 12–23 months of age. According to reported maternal exposure to permethrin, higher risk estimates were verified for children 0–11 months of age (aOR = 2.47; 95% CI: 1.17, 5.25 for ALL; and aOR = 7.28; 95% CI: 2.60, 20.38 for AML). Maternal pesticide exposure related to agricultural activities showed an aOR of 5.25 (95% CI: 1.83, 15.08) for ALL, and an aOR of 7.56 (95% CI: 1.83, 31.23) for AML.Conclusions: These results support the hypothesis that pesticide exposure during pregnancy may be involved in the etiology of acute leukemia in children < 2 years of age.     

#14-S breast-feeding and risk of childhood acute lymphoblastic leukemia: Results and commentary from a case-control study

PURPOSE: To test the hypothesis that breast-feeding mediates the occurrence of childhood ALL as a result of a rare, abnormal response to a common infection in the Northern California Childhood Leukemia Study.METHODS: Incident cases of leukemia (age 0–14) were rapidly ascertained from 1995-1999. Controls were randomly selected from the statewide birth registry and were 1:1 matched to cases on date of birth, sex, maternal race, maternal “Hispanicity,” and maternal county of residence at birth. Breast-feeding data were obtained by self-administered questionnaire and in-home interviews. Using conditional logistic regression adjusting for household income and birth weight, 140 case-control pairs were analyzed.RESULTS: Compared to no breast-feeding, breast-feeding showed a non-significant, higher risk of ALL: ever breast-fed (odds ratio (OR) = 1.16; 95% confidence interval (CI): 0.58–2.33), breast-fed ⩽6 months (OR = 1.04; 95% CI: 0.48–2.28), and breast-fed >6 months (OR = 1.31; 95% CI: 0.59-2.91). Compared to formula-fed only, breast-feeding exclusively produced no discernible pattern in ALL risk: ⩽3 months (OR = 0.85; 95% CI: 0.37–1.96), 4–6 months (OR = 1.80; 95% CI: 0.68–4.75), 7–12 months (OR = 1.23; 95% CI: 0.49–3.05), and ⩾3 months (OR = 0.81; 95% CI: 0.24–2.79).CONCLUSION: In the current literature on breast-feeding and its role in mediating childhood ALL, two recent large studies were conducted in the United States and the United Kingdom. Both studies drew differing conclusions on the effect of breast-feeding on childhood ALL. Although this study was comparatively smaller, the results do suggest further methods of elucidating the role of breast-feeding in the occurrence of childhood ALL via an infectious pathway.     

Risk factors for ectopic pregnancy: a case-control study in France, with special focus on infectious factors

A case-control study was conducted in 1988 in seven Paris area maternity hospitals to evaluate the role of several risk factors, particularly infectious factors, in ectopic pregnancy. A total of 279 cases and 279 controls were compared for sociodemographic characteristics, cigarette smoking, sexual, reproductive and surgical histories, and conditions of conception. Pelvic inflammatory disease confirmed by celioscopy (odds ratio (OR) = 5.5, 95% confidence interval (CI) 2.1-13.9) and Chlamydia trachomatis seropositivity (OR = 3.9, 95% CI 2.3-6.7) appeared to be important risk factors for ectopic pregnancy. Other risk factors found to be associated with an increased risk of ectopic pregnancy were dose-related cigarette smoking at the time of conception (ORs 1.3 to 2.5), appendectomy (OR = 1.6, 95% CI 1.1-2.5), prior tubal surgery (OR = 5.1, 95% CI 1.7-15.4), induced conception cycle (OR = 3.2, 95% CI 1.1-9.3), and prior ectopic pregnancy (OR = 13.3, 95% CI 4.5-39.2). However, some of the latter risk factors, i.e., prior tubal surgery, prior ectopic pregnancy, and perhaps appendectomy, may be considered to be the results of pelvic inflammatory disease and sexually transmitted diseases. Maternal age, parity, prior induced abortion, and prior spontaneous abortion were not associated with ectopic pregnancy. Use of intrauterine device, progestagen micropill, and also combined estroprogestative pill at the time of conception were associated with a better prevention of intrauterine pregnancy than of ectopic pregnancy. These findings confirm the importance of several previously reported risk factors of ectopic pregnancy: sexually transmitted diseases, cigarette smoking, and prior ectopic pregnancy. They also identified new risk factors, appendectomy and induced conception cycle, and revealed that the combined estroprogestative pill does not prevent ectopic pregnancy as effectively as it does intrauterine pregnancy.     

Maternal infections in pregnancy and the development of asthma among offspring.

BACKGROUND: Previous studies have suggested that asthma phenotype could probably be programmed before birth. The current study examined the impact of maternal vaginitis and febrile infections during pregnancy on the subsequent development of asthma among children. METHODS: The analyses were based on 8088 children from the northern Finland birth cohort, 1985-1986. RESULTS: The prevalence of asthma at age 7 was 3.5%. Children had a higher risk of asthma if their mothers experienced vaginitis and febrile infections during pregnancy, odds ratio (OR) = 1.41, (95% CI: 1.08-1.84) and 1.65 (95% CI: 1.25-2.18), respectively, after adjusting for other covariates. There was a clear time trend in risk of childhood asthma corresponding to the timing of maternal febrile infections in pregnancy. The adjusted OR for the first, second and third trimesters were 2.08 (95% CI: 1.13-3.82), 1.73 (95% CI: 1.09-2.75) and 1.44 (95% CI: 0.97-2.15), respectively. Maternal history of allergic diseases, birthweight <2500 g and male gender also seemed to be risk factors for childhood asthma. CONCLUSIONS: Our results suggest that further investigation of the relation of maternal infections during pregnancy to asthma among children seems warranted.     

Household exposure to pesticides and risk of childhood hematopoietic malignancies: The ESCALE study (SFCE)

OBJECTIVES: We investigated the role of household exposure to pesticides in the etiology of childhood hematopoietic malignancies. METHODS: The national registry-based case-control study ESCALE (Etude sur les cancers de l'enfant) was carried out in France over the period 2003-2004. Population controls were frequency matched with the cases on age and sex. Maternal household use of pesticides during pregnancy and paternal use during pregnancy or childhood were reported by the mothers in a structured telephone questionnaire. Insecticides (used at home, on pets, or for garden crops), herbicides, and fungicides were distinguished. We estimated odds ratios (ORs) using unconditional regression models closely adjusting for age, sex, degree of urbanization, and type of housing (flat or house). RESULTS: We included a total of 764 cases of acute leukemia (AL), 130 of Hodgkin lymphoma (HL), 166 of non-Hodgkin lymphoma (NHL), and 1,681 controls. Insecticide use during pregnancy was significantly associated with childhood AL [OR = 2.1; 95% confidence interval (CI), 1.7-2.5], both lymphoblastic and myeloblastic, NHL (OR = 1.8; 95% CI, 1.3-2.6), mainly for Burkitt lymphoma (OR = 2.7; 95% CI, 1.6-4.5), and mixed-cell HL (OR = 4.1; 95% CI, 1.4-11.8), but not nodular sclerosis HL (OR = 1.1; 95% CI, 0.6-1.9). Paternal household use of pesticides was also related to AL (OR = 1.5; 95% CI, 1.2-1.8) and NHL (OR = 1.7; 95% CI, 1.2-2.6); but for AL the relationships did not remain after adjustment for maternal pesticide use during pregnancy. CONCLUSION: The study findings strengthen the hypothesis that domestic use of pesticides may play a role in the etiology of childhood hematopoietic malignancies. The consistency of the findings with those of previous studies on AL raises the question of the advisability of preventing pesticide use by pregnant women.     

Birth characteristics and leukemia in young children

The relation between birth characteristics and leukemia in young children was investigated in a large population-based study in California. Cases were obtained from the statewide cancer registry for 1988-1997. During this time, 1,957 leukemia cases were diagnosed among children under age 5 years. Of these, 1,728 (88%) were matched to a California birth certificate. Two control birth certificates, matched on date of birth and sex, were randomly selected from the statewide birth registry for each case. Analyses were performed separately for acute lymphoid leukemia (ALL) and acute nonlymphoid leukemia (ANLL). Odds ratios and 95% confidence intervals were estimated from conditional logistic regression. The strongest finding was for greatly increased risk of both types of leukemia in children with Down's syndrome (22 cases and no controls). African-American children had strikingly decreased risk for ALL (odds ratio (OR) = 0.29, 95% confidence interval (CI): 0.20, 0.42), and Asian/Pacific Islanders had increased risk for ANLL (OR = 2.00, 95% CI: 1.19, 3.36). Older maternal age was associated with slightly increased risk for ALL (maternal age > or =35 years, OR = 1.25, 95% CI: 1.04, 1.52), although this odds ratio was somewhat reduced when adjusted for other factors. No strong relations were observed for birth weight and ALL or ANLL.     

Household Exposure to Paint and Petroleum Solvents,Chromosomal Translocations,and the Risk of Childhood Leukemia

Background

Few studies have examined the association between home use of solvents and paint and the risk of childhood leukemia.

Objectives

In this case–control study, we examined whether the use of paint and petroleum solvents at home before birth and in early childhood influenced the risk of leukemia in children.

Methods

We based our analyses on 550 cases of acute lymphoblastic leukemia (ALL), 100 cases of acute myeloid leukemia (AML), and one or two controls per case individually matched for sex, age, Hispanic status, and race. We conducted further analyses by cytogenetic subtype. We used conditional logistic regression techniques to adjust for income.

Results

ALL risk was significantly associated with paint exposure [odds ratio (OR) = 1.65; 95% confidence interval (CI), 1.26–2.15], with a higher risk observed when paint was used postnatally, by a person other than the mother, or frequently. The association was restricted to leukemia with translocations between chromosomes 12 and 21 (OR = 4.16; 95% CI, 1.66–10.4). We found no significant association between solvent use and ALL risk overall (OR = 1.15; 95% CI, 0.87–1.51) or for various cytogenetic subtypes, but we observed a significant association in the 2.0- to 5.9-year age group (OR = 1.55; 95% CI, 1.07–2.25). In contrast, a significant increased risk for AML was associated with solvent (OR = 2.54; 95% CI, 1.19–5.42) but not with paint exposure (OR = 0.64; 95% CI, 0.32–1.25).

Conclusions

The association of ALL risk with paint exposure was strong, consistent with a causal relationship, but further studies are needed to confirm the association of ALL and AML risk with solvent exposure.     

Maternal and birth characteristics in relation to childhood leukaemia

Our objective was to investigate the association of childhood leukaemia with selected maternal and birth characteristics by conducting a population-based case-control study using linked cancer registry and birth certificate records for Washington State. We compared maternal and infant characteristics of 595 Washington-born residents <20 years old with leukaemia diagnosed during 1981-2003, and 5,950 control children, using stratified analysis and logistic regression. Maternal age 35+ years (odds ratio [OR] 1.5; 95% confidence interval [CI] 1.1, 2.0), infant birthweight 4,000+ g (OR 1.4; 95% CI 1.1, 1.8), neonatal jaundice (OR 1.5; 95% CI 1.1, 2.1), and Down's syndrome (OR 31.3; 95% CI 6.4, 153.4) were associated with an increased risk of leukaemia. Among women with 2+ pregnancies, having at least two prior early (<20 weeks' gestation) fetal deaths was also associated with an increased risk (OR 1.5; 95% CI 0.97, 2.1). Maternal unmarried status (OR 0.7; 95% CI 0.6, 0.9) and African American race (OR 0.5; 95% CI 0.3, 0.9) were associated with a decreased risk. These results were more marked for acute lymphocytic leukaemia (ALL) than for acute myeloid leukaemia (AML), and for leukaemia diagnosed <5 years of age. These results may provide clues to the aetiology of childhood leukaemia. Genetic epidemiological studies are needed to expand our knowledge of inherent and possibly prenatal influences on the occurrence of this disease.     

Parental marijuana use and risk of childhood acute myeloid leukaemia: a report from the Children's Cancer Group (United States and Canada)

The aetiology of childhood acute myeloid leukaemia (AML) is largely unknown. Maternal marijuana use just before, or during pregnancy has been previously associated with childhood AML. This case-control investigation formally tested the hypothesis that parental marijuana use increases the risk of childhood AML in offspring. Incident cases of AML <18 years of age, diagnosed between 1989 and 1993, and registered with the Children's Cancer Group (a paediatric clinical co-operative group), were eligible for inclusion. Control children were selected via random digit dialling and individually matched 1:1 to cases on age, race and residential location, except for rare morphological subtypes that were matched 1:2. Parental telephone interviews were conducted to determine exposure and covariate information. Conditional logistic regression was used to estimate matched odds ratios (OR) and 95% confidence intervals [CI] adjusted for household income, parental education and parental age. The analysis included 517 cases and 610 matched controls. A series of sensitivity analyses examined the potential for recall bias. Ever lifetime use of marijuana by mothers was not associated with childhood AML [OR = 0.89; 95% CI = 0.66, 1.19]. Maternal marijuana use any time during the 3 months before, or during pregnancy was inversely associated with childhood AML [OR = 0.43; 95% CI = 0.23, 0.80]. Paternal use during the same time period was not associated with risk. Assuming a large degree of differential exposure misclassification was present, the corrected ORs ranged between 0.82 and 1.40. The previously reported positive association between maternal marijuana use before or during pregnancy and childhood AML was not confirmed. The decreased ORs observed in this study may be due to recall bias assuming plausibly low values of sensitivity.     

Household solvent exposures and childhood acute lymphoblastic leukemia

OBJECTIVES: This study explored the risk of childhood acute lymphoblastic leukemia (ALL) associated with participation by household members in hobbies or other home projects involving organic solvents. METHODS: Participants in this case-control study were 640 subjects with ALL and 640 matched controls. RESULTS: Childhood ALL was associated with frequent (> 4 times/month) exposure to model building (odds ratio [OR] = 1.9; 95% confidence interval [95% CI] = 0.7, 5.8) and artwork using solvents (OR = 4.1; 95% CI = 1.1, 15.1). We also found elevated risk (OR = 1.7; 95% CI = 1.1, 2.7) among children whose mothers lived in homes painted extensively (> 4 rooms) in the year before the children's birth. CONCLUSIONS: In this exploratory study, substantial participation by household members in some common household activities that involve organic solvents was associated with elevated risks of childhood ALL.     

Paternal military service and risk for childhood leukemia in offspring

To assess the association between paternal military service and risk for childhood leukemia, the authors analyzed data from three case-control studies conducted by the Children's Cancer Group from 1983 to 1993. A total of 605 acute myeloid leukemia (AML, age < or = 18 years) cases, 2,117 acute lymphoblastic leukemia (ALL, age < or = 14 years) cases, and 3,155 individually matched controls were included in these studies. Paternal military history and other exposure data were obtained in 2,343 matched case-control sets, including 1,805 ALL and 528 AML cases. Paternal general military service was not associated with the leukemia risk. A small, but significant, increase in the risk for AML was seen, however, among offspring of veterans who had served in Vietnam or Cambodia (odds ratio (OR) = 1.7; 95% confidence interval (CI): 1.0, 2.9), after adjustment for paternal education, race, income, smoking, X-ray exposure, and marijuana use. The risk was predominantly present in children diagnosed before the age of 2 (OR = 4.6; 95% CI: 1.3, 16.1), although there were inconsistencies in the risks associated with length of time served and interval between service and diagnosis of leukemia. Military service in Vietnam or Cambodia was unrelated to the risk for ALL. The etiologic importance, if any, of these observations has yet to be determined.     

Breastfeeding and Nutrition to 2 Years of Age and Risk of Childhood Acute Lymphoblastic Leukemia and Brain Tumors

Acute lymphoblastic leukemia (ALL) and childhood brain tumors (CBT) are 2 of the most common forms of childhood cancer, but little is known of their etiology. In 2 nationwide case-control studies we investigated whether breastfeeding, age of food introduction, or early diet are associated with the risk of these cancers. Cases aged 0–14 years were identified from Australian pediatric oncology units between 2003 and 2007 (ALL) and 2005 and 2010 (CBT) and population-based controls through nationwide random-digit dialing. Mothers completed questionnaires giving details of infant feeding up to the age of 2 yr. Data from 322 ALL cases, 679 ALL controls, 299 CBT cases, and 733 CBT controls were analysed using unconditional logistic regression. Breastfeeding was associated with a reduced risk of ALL [odds ratio (OR) = 0.52, 95% confidence interval (CI): 0.32, 0.84), regardless of duration. Introduction of artificial formula within 14 days of birth was positively associated with ALL (OR = 1.57, 95% CI: 1.03, 2.37), as was exclusive formula feeding to 6 mo (OR = 1.81, 95% CI: 1.07, 3.05). No associations were seen between breastfeeding or formula use and risk of CBT. Our results suggest that breastfeeding and delayed introduction of artificial formula may reduce the risk of ALL but not CBT.     

父母职业与儿童白血病

儿童白血病病例-对照研究,发现母亲孕期从事化学品生产及处理,金属冶炼及处理、农业及林业生产、制药及医务等工作与子代白血病危险度增高有关,母亲孕期接触苯、汽油、农药等,其子代急性淋巴及非淋巴细胞白血病均见升高,但苯的暴露与急性非淋巴细胞白血病关系更为密切。未发现父亲职业及职业暴露与儿童白血病有关。     

Refuelling of vehicles, the use of wood burners and the risk of acute lymphoblastic leukaemia in childhood

It is plausible that exposure of the parents before birth or of the child to sources of benzene increases the risk of childhood acute lymphoblastic leukaemia (ALL). The aim of this analysis was to investigate whether refuelling a vehicle with petrol before birth or burning wood to heat the home before or after the child's birth increased the risk of childhood ALL. Data from 389 cases and 876 frequency-matched controls were analysed using unconditional logistic regression, adjusting for study matching factors and potential confounders. The odds ratio (OR) for the mother ever refuelling a vehicle with petrol for non-occupational purposes before or during the pregnancy was 0.97 [95% confidence interval (CI) 0.69, 1.38]. The OR for the father for this exposure in the year before conception was 0.88 [95% CI 0.52, 1.48]. The OR for use of a closed wood burner to heat the home in the year before or during pregnancy was 1.41 [95% CI 1.02, 1.94] and 1.25 [95% CI 0.92, 1.70] after birth. We found no evidence that non-occupational refuelling a vehicle with petrol in the year before or during pregnancy increased the risk of ALL in the offspring. There was weak evidence that burning wood in a closed burner to heat the home increased the risk, but there was no dose-response relationship and chance could explain the finding.     

History of fetal loss and other adverse pregnancy outcomes in relation to subsequent risk of preterm delivery

Objective: To evaluate the association between maternal reproductive history and preterm delivery. Methods: The 312 preterm delivery cases, studied in aggregate, and in subgroups (spontaneous preterm labor, preterm premature rupture of membranes, medically induced preterm delivery, moderate preterm delivery [gestational age at delivery 34–36 weeks], and very preterm delivery [gestational age at delivery <34 weeks]), were compared with 424 randomly selected women who delivered at term. Maternal medical records provided information on maternal reproductive history, pregnancy outcome, as well as sociodemographic characteristics. Using multivariate logistic regression, we derived maximum likelihood estimates of adjusted odds ratios (OR) and 95% confidence intervals (CI). Results: A history of 2+ miscarriages was ( OR = 2.2; 95% CI 1.2–3.9), but a history of 2+ prior induced abortions (OR = 1.2; 95% CI 0.7–2.0) was not, associated with preterm delivery in the index pregnancy. Analyses of preterm delivery subgroups indicated that a history of 2+ miscarriages was associated with an increasedrisk of spontaneous preterm labor (OR = 2.6; 95% CI 1.2–2.8), preterm premature rupture of membrane (OR = 1.8; 95% 0.7–4.4), and medically induced preterm delivery (OR = 1.9; 95% CI 0.8–4.2), though only the former approached statistical significance. Excess risk of preterm delivery was associated with maternal prior history of delivering a stillborn infant (OR = 10.7), a prior history of delivering a newborn that later died during the neonatal period (OR = 3.2), and a prior history of having a pregnancy complicated by spontaneous preterm delivery (OR = 6.0). Generally these associations were evident for each subgroup of preterm delivery, though inferences were often hindered by our relatively small sample size. Conclusions: These results support the hypothesis that maternal adverse reproductive history is associated with an increased risk of preterm labor and delivery.