tokens: However , twin pregnancy ( OR : 1.957 , 95 % CI : 1.245 - 3.076 ) , illness in the first trimester ( OR : 1.306 ; 95 % CI : 1.048 - 1.628 ) , a family history of CHD ( OR : 7.156 ; 95 % CI : 3.293 - 15.552 ) , and having a child with a birth defect ( OR : 2.086 ; 95 % CI : 1.167 - 3.731 ) were positively associated with CHD .