Fetal heart screening in low-risk pregnancies.
The aim of this study was to assess whether a screening program for fetal cardiac malformations is justified in a low-risk population, and which factors influence its accuracy. The fetal heart was evaluated in 7024 pregnant women at 20-22 weeks, and evaluation was repeated at a more advanced gestational age in 9% of cases. Cardiological follow-up was continued postnatally until 2 years of age. The overall prevalence of cardiac anomaly was 0.93%. The incidences of major and minor defects were 0.44% and 0.48%, respectively. There were 23 true positives (0.33%): in 20 cases, the diagnosis was made in the second trimester, and 13 women (65%) chose termination of pregnancy. Seventeen of the 20 cases identified in the second trimester were serious malformations. There were 42 false negatives (0.60%). Of these, 12 had signs of cardiac dysfunction at birth or within the 1st month of life, and three of them died as a result of their cardiac anomaly. There were eight false positives (0.11%), all of a minor type. Six abnormal karyotypes, out of a total of 21 performed in the true-positive group (28.5%), were found. In addition, five of the 42 newborns in the false-negative group had trisomy 21. The overall sensitivity was 35.4%, and 61.3% for major defects. The accuracy in two distinct periods was estimated because the level of experience of the operators was different: sensitivity was 45.2% in period 1 (1986-88) (77.8% for major defects) and 26.5% in period 2 (1989-92) (52.9% for major defects). We conclude that a fetal heart screening program in the obstetric population is justified. It defines a high-risk group for karyotyping, allows planning of delivery in a tertiary center or the choice of terminating the pregnancy for the parents and appears to have a positive cost-benefit ratio. A crucial factor is the level of training and experience of the operators, who need specific teaching support.
Rustico
M A
MA
Department of Obstetrics and Gynecology, Instituto per l'Infanzia, Trieste, Italy.
Benettoni
A
A
D'Ottavio
G
G
Maieron
A
A
Fischer-Tamaro
I
I
Conoscenti
G
G
Meir
Y
Y
Montesano
M
M
Cattaneo
A
A
Mandruzzato
G
G
D000293:Adolescent; D000328:Adult; D003362:Cost-Benefit Analysis; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005318:Fetal Heart / Q000000981:diagnostic imaging*; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008403:Mass Screening; D011247:Pregnancy; D011256:Pregnancy Outcome; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000191:economics