טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentEilon Yael
SubjectValidity of Ultrasound Screening Tests at Different
Stages of Pregnancy in Women whom no Major
Congential Malformation was Diagnosed on
Ultrasound Examination
DepartmentDepartment of Medicine
Supervisors Clinical Professor Etan Zimmer
Mr. Shai Linn


Abstract

Background

There is no consensus regarding the need to perform an ultrasound examination in all pregnancies. Investigators in favor of ultrasound examination disagree regarding the optimal timing for examination namely, transvaginal scan at 13 - 17 weeks gestation or transabdominal scan after 20 weeks gestation.

Aims of study

a)      To evaluate the accuracy of transvaginal and transabdominal scans in cases where no fetal anomaly was detected on the initial examination. 

b)      To evaluate the impact of sonography on medical interventions in pregnancy.

Methods

This was a prospective multicenter study, women in whom no fetal anomaly was detected on the initial scan (vaginal or abdominal) were asked to complete a questionnaire containing demographic and medical pregnancy data. Following delivery they were interviewed on pregnancy and fetal outcome. In cases where a fetal anomaly was reported by the mother we evaluated the newborn's hospital file.

Main findings

The questionnaires were completed by 5522/13,252 (42%) of the women, and 4653 (85%) of them were interviewed after delivery. Six babies with severe anomalies, 9 with moderate and 69 with mild anomalies were born. The main problem was with VSD and hypospadias regarding false negative diagnosis. There were no significant differences between transvaginal and transabdominal examinations. Termination of pregnancy was performed in 13 malformed fetuses. Intrauterine fetal death occurred in 19 cases, only four of them were attributed to medical interventions.

Conclusions

Both transvaginal and transabdominal ultrasound examinations are accurate. The mode of examination should be chosen according to observer’s skills and maternal medical history.