OC26.05: Benefit of third trimester screening of small for gestational age fetuses: study in a prospective cohort of 2000 newborns

In France, an ultrasonography between 30 and 34 weeks with a biometrical evaluation is a part of current practice. Nevertheless, this practise has been poorly evaluated and the benefit of this practise has not been demonstrated through randomised study. We study the impact of third trimester sonographic small for gestational age (SGA) screening on obstetrical cares and neonatal status. We used the data of EDEN prospective cohort. 2000 inclusions were made in two university hospitals (Nancy-Poitier) before 20 weeks with a 5 years planed follow up. Usual obstetrical and neonatal data were compared between true positives (antenataly suspected and really SGA) and false negatives (SGA antenataly not diagnosed). False positives were compared to true negatives. There was no significant difference between true positives and false negatives. On the other hand, when false positives were compared to true negatives, preterm birth was significantly increased (OR = 3.3; [1.3–8.2]) as elective delivery (OR = 3.6; [1.6–8.3] and transferred to NICU (OR = 2.3 [0.9–5.7]). These results showing no clear benefit with side effects for false positive questions our practise. these should be reevaluated and modified. The use of customised chart could be a way to improve the benefit of these exams.