Study | Country Study period |
Population source | Exposure definition | Non-exposure definition | Sample size | Rmk |
---|---|---|---|---|---|---|
Källén, 2013 |
Swedish 1996 - 2011 |
Nearly all births in Sweden during the study period (1,575,847) are registered in The Swedish Medical Birth Register. | Infants whose mothers used nitrazepam in early pregnancy. (This is a subgroup of exposure among the whole exposed group considered in the study). |
unexposed (general population or NOS)
Infants in population whose mothers used at least one of a central nervous system active drugs (less than 3%) or weren't exposed in early pregnancy. |
134 / 1575847 | Follow-up period known thanks to author's email reply. |
Study | Country Study period |
Case | Control | Sample size | Rmk |
---|---|---|---|---|---|
Czeizel, 1987 |
Hungary 1970 - 1976 |
Infants born with facial clefting born during the study period. | Infants born witout facial clefting born during the study period. | 1201 / 1201 | Use of Retrospective case control study. There were 630 cases with isolated cleft lip and/or cleft palate, 179 cases with isolated cleft palate, and 392 cases of multiple congenital anomalies including cleft lip and/or cleft palate. |
Eros, 2002 |
Hungary 1980 - 1996 |
Newborn infants with isolated congenital abnormality (CA) and multiple CA. Exclusions of some mild congenital abnormalities and minor congenital abnormality (methods in Czeizel 1999). | Two or three newborn infants without congenital anomalies matched to every case according to sex, birth week in the year when the case was born, and district of parents’ residence from the National Birth Registry of the Central Statistical Office. | 22865 / 38151 | |
Sheehy, 2019 |
Canada 1998 - 2015 |
Pregnancies ending with spontaneous abortion (pregnancy loss between between the beginning of the sixth week of gestation and the 19th completed week of gestation, excluding planned or induced abortions). | Pregnancies ending with live births (5 for each case) randomly selected at the index date and matched with the case pregnancy by gestational age and calendar year. | 27149 / 134305 |