Study Title and Description
Risk factors for unexplained recurrent spontaneous abortion in a population from southern China.
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||Risk factors for unexplained recurrent spontaneous abortion in a population from southern China.|
|Author||BY Zhang,YS Wei,JM Niu,Y Li,ZL Miao,ZN Wang,|
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 used a multivariate logistic regression model to look for relationships between unexplained RSA and environmental factors as well as BMI in Chinese women, but such factors are likely to also increase the risk of sporadic miscarriage in this population.|
|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)||The test set population for the case group consisted of 326 women whose 3 to 6 miscarriages had never been investigated, and was recruited from several hospitals in the Guangzhou, Guangdong Province, southern China. The karyotypes of the women and their Partners were normal. Women with a history of endocrine or metabolic disorders, autoimmune diseases, venous thrombosis, or uterine abnormalities were excluded from the study. The 400 controls were randomly selected from pregnancy clinics. Case and control subjects were matched by age and education, and the matched pairs were genetically unrelated. A structured questionnaire was administered to collect data on coffee consumption. Caffeine content for conversion not provided. Two-sided χ2 tests were used to assess differences between cases and controls with respect to BMI, family miscarriage history, and history of smoking, ETS, and alcohol and coffee consumption. In each group, odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated using an unconditional logistic regression model, with adjustment for age, level of education, BMI, family miscarriage history, smoking, ETS, alcohol consumption, and coffee consumption.|
|How many outcome-specific endpoints are evaluated?||1|
|What is the (or one of the) endpoint(s) evaluated? (Each endpoint listed separately)||Recurrent pregnancy loss (miscarriage)|
|List additional health endpoints (separately).|
|List additional health endpoints (separately)|
|Notes||RPL defined as 3-6 miscarriages. Gestational timing of loss not defined (i.e., not specifically <20 weeks.|
|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||Patients recruited from hospitals - assumed to have medical records for outcome|
|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: never, </=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)||Two-sided χ2 tests were used to assess differences between cases and controls with respect to BMI, family miscarriage history, and history of smoking, ETS, and alcohol and coffee consumption. In each group, odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were calculated using an unconditional logistic regression model, with adjustment for age, level of education, BMI, family miscarriage history, smoking, ETS, alcohol consumption, and coffee consumption.|
|Provide a general description of results (as reported by the authors).||No correlation was found between increased risk of RSA and coffee consumption.|
|Did the authors perform a dose-response analysis (or trend/related analysis)?||Yes|
|What were the authors's observations re: trend analysis?||Not specifically addressed in text; p for trend = 0.88|
|What were the author's conclusions?||In summary, we studied relationships between environmental factors and unexplained RSA in a population from southern China using a multivariate logistic regression model. No correlation was found between increased risk of RSA and coffee consumption.|
|What were the sources of funding?||This original clinical studywas supported by a Guangdong Provincial Scientific Research Grant B2007021 offered to Bi-Yun Zhang.|
|What conflicts of interest were reported?||The authors declare that they have no conflict of interest.|
|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.||RPL (recurrent miscarriage) NOAEL = >/=300 mg/day|
|Notes regarding selection/listing of endpoints and exposures/doses to be compared to Nawrot.||ORs for all dose levels were >2 but all CI intervals spanned unity. P for trend = 0.88.|
|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.