Case-control study of maternal risk factors for fetal congenital heart diseases

Abstract

Objective To investigate maternal risk factors for fetal congenital heart diseases (CHD). Methods A case-control study was conducted on 16 645 pregnant women who underwent cardiovascular malformation screening for fetal cardiovascular system,whose pregnancy outcomes were recorded,and whose newborns were scanned by an echocardiography in Peking University People's Hospital,Haidian,Changping,Mentougou and Daxing Maternal and Child Health Hospital from Nov.2006 to Oct.2009.One hundred and twelve pregnant women whose babies were found to be CHD (40 severe CHD and 72 simple CHD) before or after delivery were taken as study group.Women in control group (n =304) were randomly selected from those pregnant women who had infants without CHD.Logistic regression analysis and x2 test were used to analyze the maternal risk factors for fetal CHD. Results (1) The average age of women whose infants had severe CHD was 28.3 years (21-40 years),and it was 29.9 years (22-39 years) for women whose infants had simple CHD.There were no significant differences between the control group (29.5 years,20-44 years) and the above two groups (t=1.511 and -0.826,P=0.138 and 0.410 respectively).(2) Single factor analysis:during first trimester,the rate of upper respiratory infection (18/39,46.2 ％) and exposure to certain chemicals (13/40,32.5％) of severe CHD group were higher than those of control group [(14.9％ (45/303) and 2.0％ (6/304)] (x2 =22.399 and 62.678,OR=4.895 and 23.753,95％CI:2.419-9.905 and 8.358-67.506,P =0.000 respectively).Compared with control group (0.0％,0/304),the rate of pregnant women with CHD family history in simple CHD group was significantly higher (4.2％,3/72)(Fisher exact test,P=0.007).(3) Logistic regression analysis:maternal upper respiratory infections (OR =5.120,95％CI:2.340-11.206,P =0.000) and exposure to certain chemicals (f)R=23.030,95％CI:7.506-70.665,P=0.000) during first trimester were risk factors for fetal severe CHD. Conclusions Upper respiratory infection and exposure to certain chemicals during first trimester might play important roles in the occurrence of fetal severe CHD.Maternal family history of CHD might associate with fetal simple CHD. Key words: Heart defects, congenital; Fetal diseases; Pregnancy complications; Risk factors; Case-control studies