Study Title and Description
Maternal caffeine intake from coffee and tea, fetal growth, and the risks of adverse birth outcomes: the Generation R Study.
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 caffeine intake from coffee and tea, fetal growth, and the risks of adverse birth outcomes: the Generation R Study.|
|Author||R Bakker,EA Steegers,A Obradov,H Raat,A Hofman,VW Jaddoe,|
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)?||Therefore, we examined in a population-based prospective cohort study among 7346 pregnant women the associations of maternal caffeine intake, based on coffee and tea consumption, with fetal growth characteristics measured in each trimester of pregnancy and the risks of adverse birth outcomes.|
|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)||Associations were studied in 7346 pregnant women participating in a population-based prospective cohort study from early pregnancy onward in the Netherlands (2001–2005). Caffeine intake in the first, second, and third trimesters was on the basis of coffee and tea consumption and was assessed by questionnaires. Information about maternal caffeine intake was obtained by postal questionnaires in the first, second, and third trimesters of pregnancy. Response rates for these questionnaires were 91%, 80%, and 77%, respectively. Mothers who reported any coffee or tea drinking were asked to categorize their average number of cups of coffee or tea per day and what type of coffee or tea they consumed (caffeinated, caffeinated and decaffeinated, or decaffeinated). According to standard values for caffeine content, a regular coffee serving (125 mL) in the Netherlands contains ~90 mg caffeine, decaffeinated coffee contains ~3 mg, and tea contains ~45 mg. To calculate the total caffeine intake in each trimester, we weighted the type of coffee or tea (caffeinated coffee = 1, caffeinated and decaffeinated coffee = 0.5, decaffeinated coffee = 0, caffeinated tea = 0.5, caffeinated and decaffeinated tea = 0.25, decaffeinated tea = 0; herbal tea = 0, and green tea = 0.5). Thus, in our analyses, each unit of caffeine intake reflects caffeine exposure based on 1 cup (90 mg caffeine) of caffeinated coffee. Information about birth outcomes was obtained from hospital records. Low birth weight was defined as birth weight ~2500 g. Small-for-gestational-age at birth was defined as a gestational age–adjusted birth weight below the 5th percentile in the study cohort (<-1.81 SD score for boys and <-1.73 SD score for girls), and preterm birth was defined as a gestational age <37 wk at delivery. We used multiple logistic regression models to assess the associations of caffeine intake with the risks of low birth weight, small-for-gestational-age, and preterm birth.|
|How many outcome-specific endpoints are evaluated?||2|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||Birth weight and SGA/IUGR|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|Notes||Also investigated fetal head circumference, fetal weight, crown-rump length, femur length, and birth length but only performed a dose-response analysis on these|
|What is the study design?||Cohort|
|Randomized or Non-Randomized?|
|What were the diagnostics or methods used to measure the outcome?||Both|
|Optional: Name of Method or short description||Medical records|
|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.)||Units caffeine: <2, 2-3.9, 4-5.9, >/=6 (1 unit = 90 mg caffeine)|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||The regression models were adjusted for lifestyle-related and socioeconomic status–related confounders used in previous studies on maternal caffeine intake (maternal height, body mass index, educational level, smoking habits, alcohol consumption, folic acid supplement use, total energy intake, total carbohydrate intake, total fat intake, and total protein intake) and known determinants of fetal growth (maternal age, maternal ethnicity, gestational diabetes, pregnancy-induced hypertension, preeclampsia, parity, and fetal sex).|
|Provide a general description of results (as reported by the authors).||Caffeine intake of >/=6 units/d was associated with an increased risk of low birth weight (adjusted odds ratio: 2.58; 95% CI: 1.26, 5.30). However, this effect estimate was based on small numbers (n = 9), and the overall tests for trend assessing the associations between the number of caffeine units and the risk of low birth weight were not significant. Caffeine intake was positively associated with the risks of delivering a small-for-gestational- age child (P <0.01). Compared with mothers who consumed <2 units caffeine/d, the adjusted odds ratios were 1.38 (95% CI: 1.08, 1.76), 1.50 (95% CI: 0.96, 2.36), and 1.87 (95% CI: 0.84, 4.15) for mothers consuming 2–3.9, 4–5.9, and >/=6 units caffeine/d, respectively (P trend <0.01). No associations were found between caffeine intake and the risk of preterm birth.|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||Yes|
|What were the authors's observations re: trend analysis?||Low birth weight: p=0.14 SGA: p<0.01 Preterm birth: p=0.83|
|What were the author's conclusions?||We showed that caffeine intake of _x0001_6 units/d during pregnancy is associated with impaired fetal weight and length growth. Length- or skeletal-related fetal growth characteristics seemed to be most consistently affected from the first trimester onward. Further structural and functional studies are needed to assess organ-specific effects. Our results suggest that pregnant women should be advised to not consume _x0001_6 caffeine units (.540 mg) per day during pregnancy.|
|What were the sources of funding?||The Erasmus Medical Center Rotterdam, the Erasmus University Rotterdam, and the Netherlands Organization for Health Research and Development (ZonMw) financially supported the first phase of the Generation R Study. VWVJ was supported by the Netherlands Organization for Health Research (ZonMw 90700303). The Generation R Study is conducted by the Erasmus Medical Center in close collaboration with the School of Law and Faculty of Social Sciences of the Erasmus University Rotterdam; the Municipal Health Service Rotterdam area, Rotterdam; the Rotterdam Homecare Foundation, Rotterdam; and the Stichting Trombosedienst & Artsenlaboratorium Rijnmond, Rotterdam. We gratefully acknowledge the contribution of general practitioners, hospitals, midwives, and pharmacies in Rotterdam.|
|What conflicts of interest were reported?||The authors had no financial commitments regarding this publication or any other conflicts of interests.|
|Does the exposure (dose) need to be standardized to the SR?||Multiple metrics|
|Provide calculations/conversions for the exposure based on the decision tree in the guide (for all endpoints/exposure levels of interest).||Note: the authors converted to units of caffeine, 1 unit = 90 mg caffeine Low birth weight: >/=6 units/day = LOAEL 6 units/day x 90 mg = 540 mg/day SGA: >/=6 units = NOAEL 6 units/day x 90 mg = 540 mg/day Preterm birth: >/=6 units = NOAEL 6 units/day x 90 mg = 540 mg/day|
|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.||Low birth weight: LOAEL = 540 mg/day SGA: NOAEL = 540 mg/day Preterm birth: NOAEL = 540 mg/day|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||Only these endpoints had quantitative values comparable to PECO. Low birth weight: OR = 2.58 (1.26-5.30) SGA: ORs = 1.38 (95% CI: 1.08, 1.76), 1.50 (95% CI: 0.96, 2.36), and 1.87 (95% CI: 0.84, 4.15) for mothers consuming 2–3.9, 4–5.9, and >/=6 units caffeine/d, respectively (P trend <0.01) Preterm birth: OR = 1.35 (0.58-3.15)|
|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.