Study Title and Description
Maternal consumption of coffee and caffeine-containing beverages and oral clefts: a population-based case-control study in Norway.
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 consumption of coffee and caffeine-containing beverages and oral clefts: a population-based case-control study in Norway.|
|Author||AM Johansen,AJ Wilcox,RT Lie,LF Andersen,CA Drevon,|
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)?||Coffee is a commonly consumed beverage among pregnant women, and even a small increase in malformation risk could be a matter of concern.We used data from a population based case-control study to evaluate the association of maternal consumption of coffee and caffeinated beverages in early pregnancy with the risk of delivering an infant with an orofacial cleft|
|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)||Large, population-based case-control study of facial clefts; 573 cases (identified in treatment) —377 with cleft lip with or without cleft palate and 196 with cleft palate only—and 763 randomly selected controls. Accompanying defects were reported for 17% of CLP cases and 40% of CPO cases. Cases of clefts without accompanying defects have been categorized as isolated clefts. Mothers completed a 32-page questionnaire. Median time from delivery to completion of the questionnaire was 14 weeks for cases and 15 weeks for controls. The questionnaire included items on maternal consumption of caffeine-containing beverages (coffee, tea, and soft drinks) during the first 3 months of pregnancy. For each beverage, there was 1 question with 5 response categories: none, number of cups per day, number of cups per week, number of cups per month, and number of cups per year (without specifying the size of the cup). An English translation of the questionnaire is available online (http://www.niehs.nih.gov/research/atniehs/labs/epi/ studies/ncl/ncl_pregnancy_en.pdf). An estimate of caffeine from all sources was computed from the data on coffee, tea, and caffeinated soft drinks. Caffeine content was estimated as 100 mg per cup of coffee, 40 mg per cup of tea, and 20 mg per cup of caffeinated soft drink based on values from the Norwegian Health Authorities. The risk of delivering offspring with orofacial cleft was estimated by OR using unconditional linear regression. Adjustments were made for potential confounders (factors associated with clefts in other studies, most of which were also associated in our study), namely, dietary vitamin A (quartiles), dietary folate (quartiles), folic acid supplement (400 l g/day, yes or no), vitamin supplement use (yes or no), consumption of alcohol in early pregnancy (number of drinks per sitting), smoking (ordinal linear with 5 categories: none; passive only; and 1–5, 6–10, and >/= 11 cigarettes a day), nausea during the first trimester (yes or no), employment in early pregnancy (yes or no), education (ordinal linear with 6 categories), father’s income (ordinal linear with 3 categories), and year of birth. Evaluations of possible interactions with coffee intake were carried out for use of folic acid supplements and smoking. In evaluating the effects of coffee or tea separately, we adjusted for the other (categorized as number of cups per day).|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||orofacial clefts - cleft lip with or without clef palate; cleft palate|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|What is the study design?||Case-Control|
|Randomized or Non-Randomized?|
|What were the diagnostics or methods used to measure the outcome?||Objective|
|Optional: Name of Method or short description||Identified as children requiring surgery for cleft|
|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: 0-100, >100-<500, >/=500|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||Adjustments were made for potential confounders (factors associated with clefts in other studies, most of which were also associated in our study), namely, dietary vitamin A (quartiles), dietary folate (quartiles), folic acid supplement (400 lg/day, yes or no), vitamin supplement use (yes or no), consumption of alcohol in early pregnancy (number of drinks per sitting), smoking (ordinal linear with 5 categories: none; passive only; and 1–5, 6–10, and _x0001_11 cigarettes a day), nausea during the first trimester (yes or no), employment in early pregnancy (yes or no), education (ordinal linear with 6 categories), father’s income (ordinal linear with 3 categories), and year of birth. Evaluations of possible interactions with coffee intake were carried out for use of folic acid supplements and smoking. In evaluating the effects of coffee or tea separately, we adjusted for the other (categorized as number of cups per day).|
|Provide a general description of results (as reported by the authors).||Maternal coffee consumption was associated with an increased risk of CLP. In the adjusted analyses, the odds ratio of CLP increased by 7% per-cup increase in daily coffee intake (adjusted odds ratio = 1.07, 95% confidence interval (CI): 1.00, 1.16). Compared with those for women with zero coffee consumption, the adjusted odds ratios of CLP were 1.39 (95% CI: 1.01, 1.92) for daily coffee consumption of less than 3 cups a day and 1.59 (95% CI: 1.05, 2.39) for consumption of 3 or more cups a day, and inspection of categories of coffee intake confirmed that there was a trend in risk by dose (Ptrend = 0.013 in the adjusted analyses). Consumption of caffeine-containing tea was associated with a decrease in the odds ratio of both CLP and CPO. Although there was a positive association in the crude analysis for total caffeine, the association was reduced after adjustment.|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||Yes|
|What were the authors's observations re: trend analysis?||P values for trend were 0.834 and 0.297 in adjusted analyses for caffeine|
|What were the author's conclusions?||In summary, results from our study showed a dosedependent association between coffee consumption during the first trimester and increased risk of CLP. This association was specific to CLP, with no association found between coffee consumption and risk of CPO. There was little or no evidence for an association between caffeine from other types of beverages and CLP. Even with extensive adjustments for confounders, we cannot eliminate the possibility that the associations between coffee consumption and risk of CLP are due to uncontrolled confounding by factors associated with the habit of drinking coffee. Still, considering our results and the prior mixed evidence for a coffee effect on clefts, women cannot be assured that maternal coffee consumption is entirely benign for the developing fetus. Other clefts studies now in progress should give close attention to a possible association of coffee consumption with facial clefts.|
|What were the sources of funding?||This work was supported by the Research Council of Norway (grant 166026/V50); the Freia Medical Foundation; the Throne-Holst Foundation for Nutrition Research; the thematic area of perinatal nutrition, Faculty of Medicine, University of Oslo, Oslo, Norway; and Nutrigenomics, Network of Excellence, FP6, Food Quality and Safety (NuGO FP6-506360). This research was supported in part by the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences.|
|What conflicts of interest were reported?||None declared|
|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.||Cleft lip with or without palate NOAEL = >/=500 mg/day Cleft palate NOAEL = >/=500 mg/day|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||Caffeine content was estimated as 100 mg per cup of coffee, 40 mg per cup of tea, and 20 mg per cup of caffeinated soft drink based on values from the Norwegian Health Authorities.|
|What is the importance of the study with respect to the adverseness of the outcome?||Critcal|
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.