CONGENITAL HEART-DEFECTS - NATURAL COURSE AND IN-UTERO DEVELOPMENT

Background Most congenital heart defects (CHDs) are diagnosed on targe ted prenatal transvaginal (TVS) or transabdominal (TAS) ultrasonograph y during the early second trimester or at midgestation. Nevertheless, delayed diagnosis in some cardiac malformations still remains despite detailed echocardiographic examination. The present study was conducte d to evaluate the evolution of fetal cardiac anomalies and assess thei r development in utero. Methods and Results We retrospectively reviewe d 22050 pregnant women who were divided into two groups: 6924 who had initial TVSs at 13 to 16 weeks' gestation, followed by TASs at 20 to 2 2 weeks, and 15 126 who had initial TASs at 20 to 22 weeks. Both group s were subsequently examined in their third trimester. All newborns we re examined by certified pediatricians. CHD was diagnosed in 168 babie s: 66 in group A and 102 in group B. In group A, 42 malformations (64% ) were detected at the first TVS examination, and 11 (17%) were found during the subsequent TAS. Three additional anomalies (4%) were found during the third trimester, and 10 malformations (15%) were detected p ostnatally. In group B, 80 malformations (78%) were detected in the in itial examination at midtrimester, and an additional 7 (7%) were found in the third trimester, whereas 15 (15%) were diagnosed postnatally. The 19 anomalies (group A, n=3; group B, n=7) that were detected only during the third trimester comprised aortic stenosis (n=2), cardiac rh abdomyoma (n=2), subaortic stenosis (n=1), tetralogy of Fallot (n=1), aortic coarctation (n=1), sealed foramen ovale (n=1), ventricular sept al defects (n=1), and hypertrophic cardiomyopathy (n=1). Conclusions A lthough most fetal cardiac anomalies are detectable early in gestation , some may evolve in utero at different stages of pregnancy.