P06.03: Establishment of a first trimester screening service in Brazil: first impressions

Abstract

Objectives: In the last decades, the first trimester has been attracting more and more attention from researchers around the world. This started with the technological improvement of the ultrasound machines, and changed the way many obstetrical pathologies were detected. In this subject, the early screening for chromosomal anomalies, pre-eclampsia and intra-uterine growth restriction had produced promising studies. Our goal was to start a service dedicated to perform the first trimester screening in Sao Paulo Federal University, in a similar way to the screening described in actual literature, meanwhile producing useful research regarding this important subject and improving the knowledge of our medical personnel. Methods: The service flowchart was 1) Initial interview – explaining the screening purpose, identifying risk factors and obtaining related information; 2) Clinical exam and measurement of weight, height and blood pressure; 3) Ultrasound scan; 4) Blood sample; 5) Counseling. In the ultrasound exam, besides the structural evaluation, the following markers are evaluated: nuchal translucency (NT), nasal bone (NB), facial angle (FA), ductus venosus A wave (DV) and tricuspid regurgitation (TR). The uterine artery Doppler indexes are also measured. From the maternal blood sample we obtain free βhCG, PAAP-A and PP-13 concentration. Results: During the initial six months, we evaluated 136 pregnant women that gave written consent to enroll our study. In our sample, 3% of the patients presented a NT above the 95th centile. Feasibility of the other markers was 97% for NB, 95% for FA, 95% for DV and 86% for TR. Uterine Doppler was successfully performed in all cases. Conclusions: These initial results showed that in a short period of time it is possible to establish a first trimester screening service with results similar to the ones described in recent literature. The next step is to correlate our screening results with the pregnancy outcomes and enlarge our sample.