P25.05: First trimester diagnosis of fetal anomalies‐ a beneficial sequel to the introduction of first trimester screen (FTS) anueploidy program

Abstract

To present ultrasound diagnoses made at the time of FTS, and discuss the additive benefit of early ultrasound for aneuploidy. First trimester screening using nuchal translucency (NT) and maternal serum analytes has resulted in more sonographic time spent in the first trimester by highly trained individuals in order to obtain specific images. We reviewed results between January 2007 and January 2008 after the implementation of the FTS program for all women who presented at the correct gestational age. We performed 2432 first trimester screens. A total of 48 major fetal anomalies were detected in the year, and of these 16 were in the first trimester (33%). Only 6 of the 16 women had increased NT. Thirty of the 48 women (63%) diagnosed with major anomalies did not have FTS and were detected by 2nd trimester ultrasound examination. We present 16 cases and images from one year that led to a diagnosis in the first trimester, and their pregnancy outcome. Of the abnormalities detected in the 1st trimester, approximately 70% occurred in women under 35 years old who otherwise would not have an indication for early prenatal diagnosis. The timing of their ultrasounds was solely responsible for the early diagnosis. Eighty-seven percent of the women presented chose to terminate an abnormal pregnancy after early diagnosis. Emotional and medical risks associated with an abnormal pregnancy become limited with early diagnosis. We propose that with highly skilled sonographic examiners performing first trimester ultrasounds, there is also opportunity for early structural diagnosis of severe anomalies that impact on pregnancy outcome. It is likely that the different emotional effect and lower medical risk associated with early pregnancy termination may prove to be of benefit to the patient.