Michele Lauria MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: To determine the impact of instituting a structured genetic sonogram (GS) on the care of pregnant women at low risk for Down Syndrome (DS). Methods and Materials: A structured genetic sonogram scoring system for a standard 15-20 week fetal sonogram was created for women at low risk for fetal aneuploidy based on serum screening and age. A 2 phase study was performed, retrospective and prospective. Sonograms performed at 15-20 weeks from 7/99-12/99 were retrospectively scored. Referrals for prenatal diagnosis PND) during the retrospective phase (RP) were at the sonologist's discretion. From 3/00-9/01, sonograms at 15-20 weeks gestation sonograms were prospectively scored. Points were administered as follows: ultrasound major markers 2 points, ultrasound minor markers 1 point, and CPC 1 point. Women were referred for PND for 1) any major marker, 2) two minor markers, or 3) choroid plexus cysts. PND referrals and DS cases were determined by database and medical record review. Additional pregnancy outcomes in the prospective phase (PP) were obtained via chart review, follow-up letters, delivery logs and referral logs. GS scores and PND referrals in the two phases were compared using Chi square analysis. Results: The rate of isolated minor marker detection was unchanged, 22/243 (9.1%) RP, 45/434 (10.4%) PP. Excluding CPC, 35.3% (6/17) of RP women with isolated minor markers and 6.9% (2/29) of PP women were referred for PND (p < 0.05). One woman in the RP group with an isolated marker uderwent amniocentesis; this did not occur during the prospective phase. There were 5 RP scores of 2 (2%), all due to anomalies, one underwent amniocentesis. 13 PP ultrasounds scored 2 (2.9%): 6 due to major malformations, 2 for thickened nuchal folds, and 5 with multiple minor markers. Eleven were referred for PND, five underwent amniocentesis. No fetus with an isolated minor marker had DS. In the PP, three fetuses had anueploidy and two were diagnosed prenataly. The undiagnosed case occurred in a morbidly obese diabetic patient where adequate imaging could not be obtained, even with fetal echocardiography. Conclusion: Minor markers for DS are often evaluated and reported in low risk women, despite the lack of prospective studies evaluating the impact of screening and its sensitivity. In our institution, using a structured GS with sonographic criteria for increasing DS risk, decreased inappropriate referrals for PND. Further research is needed to determine the best markers for screening low risk women.       Questions about this event email: Michele.Lauria@hitchcock.org

Lauria MD, M, Systematic Genetic Sonogram Screening in a Low Risk Population.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3101268.html