Study Title and Description
Maternal exposure to tobacco smoke, alcohol and caffeine, and risk of anorectal atresia: National Birth Defects Prevention Study 1997-2003.
Key Questions Addressed
|1||For [population], is caffeine intake above [exposure dose], compared to intakes [exposure dose] or less, associated with adverse effects on reproductive and developmental outcomes?|
Primary Publication Information
|Title||Maternal exposure to tobacco smoke, alcohol and caffeine, and risk of anorectal atresia: National Birth Defects Prevention Study 1997-2003.|
|Author||EA Miller,SE Manning,SA Rasmussen,J Reefhuis,MA Honein, ,|
Secondary Publication Information
There are currently no secondary publications defined for this study.
Extraction Form: Reproductive Toxicity - Design Details
No arms have been defined in this extraction form.
|Question... Follow Up||Answer||Follow-up Answer|
|What outcome is being evaluated in this paper?||Reproductive and Development|
|What is the objective of the study (as reported by the authors)?||To determine whether maternal exposures to alcohol, tobacco smoke or caffeine during the periconceptional period – from 1 month before pregnancy to the first trimester – are associated with anorectal atresia, we examined data from the National Birth Defects Prevention Study (NBDPS). We also assessed whether caffeine intake modified the association between tobacco exposure or alcohol intake with anorectal atresia.|
|Provide a general description of the methods as reported by the authors. Information should be extracted based on relevance to the SR (i.e., caffeine related methods)||Multistate case-control study with 464 infants with anorectal atresia and 4940 infants with no major birth defects. Case infants were identified from 10 with population-based birth defects surveillance systems. Clinical information abstracted from medical records of each case infant was reviewed by a clinical geneticist. Our analysis included infants with anal or rectal atresia (including rectal stenosis) with or without fistula. Infants with anal stenosis or anteriorly placed anus (without other eligible defects) were excluded from the NBDPS because of concern that these defects may have been inconsistently ascertained. In addition to the routine case review by clinical geneticists at each site, all infants with a diagnosis of anorectal atresia/rectal stenosis were reviewed by a clinical geneticist (S.A.R.) to ensure that they met the case inclusion criteria and to further classify cases using guidelines developed for the NBDPS Control infants are a random sample of livebirths from the same geographically defined region. Infants with major structural birth defects are excluded from the control group, but there are no other health-related exclusions (e.g. minor defects, low birthweight, other illnesses). Mothers of all infants were interviewed by telephone 6 weeks to 24 months after the estimated date of delivery. Caffeine intake was derived from the dietary portion of the questionnaire, which assessed dietary habits during the year before pregnancy. Levels of caffeine intake were based on questions regarding consumption of coffee, tea, soda (soft drinks) and chocolate. Women were also asked if intake of coffee, tea or soda increased, decreased or stayed the same during pregnancy compared with their reported consumption during the year before pregnancy. Caffeine content (mg/oz) for tea and coffee was calculated based on findings reported previously. If available, brand-specific caffeine values were used for soda and soft drink intake. Caffeine intake from chocolate was assigned 10 mg/serving and ascertained through a food frequency questionnaire. Caffeine intake was examined from all sources combined and for each source separately. We used unconditional logistic regression to determine the association of exposure to smoking, environmental tobacco smoke (ETS), alcohol or caffeine with anorectal atresia. The variables considered as potential confounders in this analysis included maternal race/ ethnicity, age, education, pre-pregnancy body mass index (BMI), prenatal care, folic acid use, high blood pressure, parity, history of stillbirth or miscarriage, family income, and state of maternal residence at delivery. Alcohol, tobacco and caffeine were examined as potential confounders Effect modification by caffeine intake was assessed on additive and multiplicative scales.|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||anorectal atresia|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|Notes||included infants with anal or rectal atresia (including rectal stenosis) with or without fistula|
|What is the study design?||Case-Control|
|Randomized or Non-Randomized?|
|What were the diagnostics or methods used to measure the outcome?||Both|
|Optional: Name of Method or short description||In addition to the routine case review by clinical geneticists at each site, all infants with a diagnosis of anorectal atresia/rectal stenosis were reviewed by a clinical geneticist (S.A.R.) to ensure that they met the case inclusion criteria and to further classify cases using guidelines developed for the NBDPS|
|Caffeine (general)||Caffeine (general)|
|Pregnant Women||Pregnant Women|
|What was the reference, comparison, or control group(s)? (e.g. high vs low consumption, number of cups, etc.)||Caffeine mg/day: <10, 10-99, 100-299, >/=300|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||The variables considered as potential confounders in this analysis included maternal race/ ethnicity, age, education, pre-pregnancy body mass index (BMI), prenatal care, folic acid use, high blood pressure, parity, history of stillbirth or miscarriage, family income, and state of maternal residence at delivery. Alcohol, tobacco and caffeine were examined as potential confounders.|
|Provide a general description of results (as reported by the authors).||Higher caffeine intake was positively associated with anorectal atresia. Compared with women who consumed <10 mg/day, the ORs for 10–99 mg/day, 100–299 mg/day and >/=300 mg/day were 1.4 [CI 1.0, 1.9], 1.3 [CI 1.0, 1.8] and 1.5 [CI 1.0, 2.2] respectively. The strongest association with isolated defects was among women with caffeine intake of 100– 299 mg/day (OR = 1.9 [CI 1.2, 3.0]). There was no association with anorectal atresia when examining caffeine intake by each source individually (data not shown). Because caffeine intake was assessed for the year prior to pregnancy, results were examined again by assessing reported changes in consumption during pregnancy. Women with caffeine intake <10 mg/day during the year before pregnancy were restricted to those who reported drinking the same amount or more of coffee, tea and soda during pregnancy. The reference group were women with a caffeine intake of <10 mg/ day before pregnancy who consumed the same, less or no caffeine during pregnancy. Compared with women who consumed <10 mg/day, the associations with all anorectal atresia cases for 10–99 mg/day, 100–299 mg/ day and >/=300 mg/day were 2.6 [1.2, 5.6], 2.1 [1.0, 4.4] and 2.6 [1.2, 6.0] respectively.|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||Yes|
|What were the authors's observations re: trend analysis?||NOTE: Trend analysis was not performed; however, authors state the following: It should be noted that the association found in this study did not linearly increase with higher caffeine intakes and that a borderline statistically significant association was detected even at very modest intake levels (10–99 mg/day), which represents less than one 10-oz cup of coffee per day.24 The lack of dose response could be evidence against a causal effect or could be due to imprecision in dose categorisation because of differences in cup sizes consumed, caffeine levels of different brewing techniques, and differences in caffeine content by the specific type of coffee brewed, which has been raised as a concern in other studies examining caffeine intake during pregnancy.33|
|What were the author's conclusions?||Our study provided some evidence that exposure to tobacco smoke and caffeine intake may be associated with anorectal atresia. Because the biological plausibility of these associations with this particular defect is unknown and associations with ETS and caffeine intake have not been reported previously, additional studies are needed to replicate the results.|
|What were the sources of funding?||Supported by the Centers for Disease Control and Prevention.|
|What conflicts of interest were reported?||None reported|
|Does the exposure (dose) need to be standardized to the SR?||No|
|Provide calculations/conversions for the exposure based on the decision tree in the guide (for all endpoints/exposure levels of interest).|
|List all the endpoint(s) followed by the dose (mg) which will be used in comparison to Nawrot. Characterize value as LOAEL/NOAEL, etc. if possible.||anorectal atresia LOAEL = 10-99 mg/day|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||Compared with women who consumed <10 mg/day, the ORs for 10–99 mg/day, 100–299 mg/day and >/=300 mg/day were 1.4 [CI 1.0, 1.9], 1.3 [CI 1.0, 1.8] and 1.5 [CI 1.0, 2.2] respectively. No linear response observed, effects even at <1 cup/day, and all CIs start at 1.0.|
|What is the importance of the study with respect to the adverseness of the outcome?||Important|
No baseline characteristics have been defined for this extraction form.
Results & Comparisons
No Results found.
|Arm or Total||Title||Description||Comments|
No quality dimensions were specified.
No quality rating data was found.