Table 1.
Characteristics of studies included in the pooled analysis of maternal first trimester alcohol consumption and infant cleft risk
| Study; no. cases/no. controls; design | Period of Enrollment (Birth years) | Location | Case Ascertainment | Control Ascertainment | Mode of exposure ascertainment; timing of completion | Participation Rates | Selected characteristics of control mothers | ||
|---|---|---|---|---|---|---|---|---|---|
| Age range (mean) | Smoking first trimester % |
Education <high school % |
|||||||
| DNBC; 179/828; Case–control analysis nested within cohort |
1998–2002 | Denmark | Live births Danish Facial Cleft Registry |
Live births Random selection from DNBC |
In-person interview; Week 17 of pregnancy (mean) | 30 % | 17–43 (30.0) | 26.6 | 28.2 |
| Iowa; 287/302; Case–control study |
1987–1991 | Iowa, USA | Live births, stillbirths, and elective terminations Iowa State Registry of Congenital and Inherited Disorders |
Live births Random selection from Iowa birth Certificates |
Telephone interview; 2.5 months after delivery (mean) | Cases 74 % Controls 55 % |
15–41 (27.1) | 22.2 | 7.6 |
| MoBa; 184/551; Case–control analysis nested within cohort | 2000–2009 | Norway | Live births Norway Medical Birth Registry |
Live births Random selection from MoBa |
Mailed questionnaire; Weeks 15 and 30 of pregnancy | 45 % | 18–44 (30.0) | 23.8 | 2.6 |
| NBDPS; 3491/8357; Case–control study |
1997–2008 | 10 states, USA | Live births, stillbirths, and elective terminations State birth defect registries |
Live births Random selection from birth certificates; frequency matched to cases by state and date of birth |
Telephone interview; 6–24 months after delivery | Varied by state: Cases 58–77 % Controls 63–73 % |
13–49 (26.9) | 16.3 | 17.3 |
| NCL; 570/763; Case–control study | 1996–2001 | Norway | Live births Referral from 2 surgical centers (Oslo, Bergen) handling all cleft repair in Norway |
Live births Random selection from Norway MBR |
Mailed questionnaire; 14 weeks after delivery for cases and 15 weeks after delivery for controls (mean) | Cases 88 % Controls 76 % |
16–44 (29.2) | 31.9 | 11.4 |
| Utah; 561/660; Case–control study | 1995–2004 | Utah, USA | Live births, stillbirths, and elective terminations Utah Birth Defects Network |
Live births Random selection from Utah birth certificates; frequency matched to cases by month and year of delivery and sex of child |
Telephone interview (in-person interview if telephone not available); 3–4 years after delivery | Cases 87 % Controls 85 % |
15–44 (26.8) | 8.0 | 6.5 |
DNBC Danish National Birth Cohort, MoBa Norwegian Mother and Child Cohort Study, NBDPS National Birth Defects Prevention Study (United States), NCL Norway Facial Clefts Study