Table 1: Study population characteristics.

Use of trimethoprim in the 12-week period prior to pregnancyNo use of trimethoprim in the 12-week period prior to pregnancy

Age (year)28.529.7
Parity (mean)1.801.85
Household income—number (%)
 <$50,00076 (19)80,899 (16)
 $50,000–$100,000194 (48)241,907 (46)
 $100,000–$150,000110 (27)150,163 (29)
 >$150,00022 (5)48,240 (9)
Education—number (%)
 Low168 (42)182,072 (35)
 Medium123 (31)165,132 (32)
 Long98 (24)149,324 (29)
 No information available10 (2)13,333 (3)
Comorbidityb—number (%)
 Teratogenic infectious diseasesc1a (0.3)133 (0.0)
 Folate deficiency0 (0)39 (0.0)
 Myasthenia gravis0 (0)38 (0.0)
 Virilizing tumors0 (0)84 (0.0)
 Diabetes Mellitus4 (1)6258 (1)
 Alcoholism0 (0)111 (0.0)
 Amniocentesis1a (0.3)5381 (1.0)
 Sjogren’s syndrome0 (0)38 (0.0)
 HIV/AIDS0 (0)60 (0.0)
Pneumocystis carinii pneumonia0 (0)2 (0.0)
 Previous organ transplantation1a (0.0)49 (0.0)
Use of folic acid—number (%)9 (2)4296 (1)

aNone had offspring with a congenital malformation. bAll information on comorbidity were based on diagnoses from the National Hospital Register. cSyphilis, toxoplasmosis, rubella virus, varicella virus, parvovirus B-19, cytomegalovirus, herpes simplex viruses 1 and 2, and Venezuelan equine encephalitis virus.