Ultrasonography (US) is currently the main diagnostic tool in the prenatal detection of fetal malformations. It allows to perform both a biometric and morphologic evaluation of the fetus and to diagnose not only major malformations but also minor anomalies - markers of cromosomal abnormalities - and genetic syndrome. Ultrasound is a method codified by guidelines that assist the operator in his/her job and provide the patient with adequate information on diagnostic possibilities and limits of the method. Ultrasound validity is worldwide acknowledged in high risk pregnancies but its usefulness as a screening method of general population (low risk of congenital malformations) is still a matter of discussion. Some studies of screening in large low risk populations (incidence of major abnormalities ranging from 1,4% to 2,5%) carried out with ultrasound before the 24th week of gestation showed that prenatal ultrasound examination has excellent specificity and negative predictive value (99,9% and 98-99,5% respectively) while the range of sensitivity and positive predictive value is very wide (17,71% and 75-98% respectively). Since some researchers pointed out that no significant differences arose between the group who underwent routine ultrasound and the control group with regard to the perinatal outcomes (mortality and morbidity) of fetuses affected by malformations, there are conflicting opinions - based on different studies - about the validity of ultrasound screening in low risk pregnancies. The conflicting results may derive from studies based on different samplings of population and they may also depend on the experience of the sonologist and sonografer. It is easy to understand how the results of the analysis of a sample of low risk obstetric population differ completely from whose obtained in high risk or neonatal surgical population. In theory, the group of anomalies diagnosed prenatally can be the expression of a more severe pathology therefore more evident and easier to diagnose ultrasonographically. If this holds true and even though the neonatal outcomes of the group who was offered ultrasound scan are the same as those of the control group, all the same, patients benefit from ultrasound prenatal diagnosis especially because it improves perinatal management and allows to take into accounts neonatal intensive care, if required. Nonetheless prognosis depends on the severity of the malformation.
|Translated title of the contribution||Present possibilities of prenatal diagnosis|
|Number of pages||33|
|Publication status||Published - 2000|
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health