Study Title and Description
High caffeine consumption in the third trimester of pregnancy: gender-specific effects on fetal growth.
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||High caffeine consumption in the third trimester of pregnancy: gender-specific effects on fetal growth.|
|Author||T Vik,LS Bakketeig,KU Trygg,K Lund-Larsen,G Jacobsen,|
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)?||We have in the present study used data from a prospective multicentre study on causes and consequences of being born small for gestational age (SGA) in Scandinavia to test the hypothesis that caffeine is associated with an increased risk of giving birth to an SGA infant. We were in particular interested in studying gender-specific effects, but we did not have an a priori hypothesis on which sex would be most affected.|
|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)||intake among 747 mothers of non- SGA infants (368 boys, 379 girls). In the second (i.e. at the first study visit before week 20) and the third trimester (i.e. week 33), 3 days of dietary records were prospectively recorded. The pregnant woman was asked to record her food intake at the time the food was eaten. Data were collected during the same three weekdays (Tuesday, Wednesday, Thursday) in both periods. The amounts of food consumed were given in household measures, supplemented by food models presented as a booklet with full scale drawings. Internal validity was tested against a food frequency questionnaire in a comparable group of non-pregnant Norwegian women.Reference values of mg caffeine per 100 ml (100 g chocolate) were: cola 13.0, coffee 57.4, tea 27.0, chocolate milk 2.1, chocolate 66.7. Gestational age was based upon the first day of the last menstrual period (LMP) if this was accurately recalled within ±3 days at the first visit. However, ultrasound was used to date the pregnancy if it differed by more than 14 days from the LMP-based gestational age, or if the LMP could not be recalled accurately. SGA was defined as a birthweight below the 10th percentile for gestational age, corrected for sex and parity. Caffeine intake was dichotomised, creating two groups of women by choosing a cut-off point at the median value for the total population. At week 17 (early second trimester) the median caffeine intake was 232 mg/day, at week 33 (mid-third trimester) it was 205 mg/day, and the median intake of both periods was 223 mg/day. A caffeine intake below these values was defined as ‘low’, while an intake equal to or above it was defined as ‘high’. The odds ratio (OR) was calculated and used as an estimate of the relative risk that a mother with a ‘high’ intake of caffeine had an increased risk of giving birth to an SGA infant, compared with a mother with a ‘low’ intake.|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||SGA (IUGR)|
|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||SGA was defined as a birthweight below the 10th percentile for gestational age, corrected for sex and parity|
|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.)||1) Low vs. high caffeine = 223 mg/day over both periods 2) Caffeine quartile - mg/day: 0-109.9, 110-204.9, 205-309.9, >/=310|
|What were the listed confounders or modifying factors as stated by the authors? (e.g. multi-variable components of models. Copy from methods)||1) Low vs. high caffeine - adjusted for smoking at pregnancy, prepregnancy weight, low education and previous SGA birth 2) Quartile caffeine - none|
|Provide a general description of results (as reported by the authors).||The risk of giving birth to an SGA infant was increased in mothers who had high intakes of caffeine at week 33 (OR 1.8; 95% CI 1.2, 2.7) compared with mothers who had a low intake (Table 4 – [note: unadjusted]). A high caffeine intake during week 17–20 was borderline significantly associated with an increased risk of SGA birth. Caffeine in the third trimester was associated with a nearly threefold increased risk of being SGA at birth in males [OR 2.8; 95% CI 1.5, 5.2]. In contrast, there was no evidence of such an association if the fetus was of female gender (OR 1.2; 95% CI 0.7, 2.1). Caffeine intake early in the second trimester was not associated with an increased risk of delivering an SGA infant, regardless of gender (Table 5). The adjusted ORs show the same pattern for the total population as the crude ORs. A significant trend was reported using caffeine quartiles for the total population (p=0.001) and boys (<0.001) but not girls (p=0.22).|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||Yes|
|What were the authors's observations re: trend analysis?||Significant trend for total population (p=0.001) and boys (<0.001) but not girls (p=0.22)|
|What were the author's conclusions?||In conclusion, we have found that a high intake of caffeine in the third trimester of pregnancy is associated with an increased risk of being born as SGA in male, but not in female fetuses.|
|What were the sources of funding?||The study was supported by the US National Institute of Child Health and Human Development, NIH (NICHD contract No. 1-HD-4–2803 and No. 1-HD-1– 3127).|
|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.||1) Low vs. high adjusted - LOAEL = high (>223 mg/day) 2) Quartiles - LOAEL unadjusted = 110-204.9 mg/day|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||1) Low vs. high adjusted by gender: LOAEL = high (>223 mg/day) males; no significance in females 2) Quartiles unadjusted by gender: LOAEL = 205-309.9 males; no significance in females|
|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.