[Investigating into whether systematic fetal weight estimation by ultrasound in the delivery room increases the risk of cesarean delivery].

Ultrasound is a valuable tool commonly used in the delivery room. It has multiple applications. The objective of this study was to investigate whether systematic fetal weight estimation by ultrasound in the delivery room increases the risk of cesarean delivery. Monocentric cohort study. All parturients with singleton pregnancies who gave birth full-term at = 39 weeks were enrolled in the study. We excluded all patients with a contraindication to vaginal birth as well as those in whom fetal weight estimation (FWE) by ultrasound on day of delivery was deemed necessary in making obstetric decision. Parturients enrolled in the study were divided into two groups: - G1: parturients who systematically underwent FWE - G2: parturients who never underwent FWE. We compared cesarean delivery rate with adjustment for potentially confounding factors according to logistic regression. 838 parturients were enrolled in the study. Prematurity, FWE and weight at birth were risk factors for cesarean delivery. After adjustment for confounding factors, FWE by ultrasound systematically performed in G1 proved to be an independent risk factor for cesarean delivery with OR = 3.8 (CI 95% = [2.67 to 5.48]). This risk increased significantly with estimated fetal weight (EFW): OR=2,27(CI 95;1,15-4,47; p=0.018) for 3500 < EFW < 4000g and OR = 10.64 (CI 95; 4.28 to 26.41; p < 0.001 ) for EFW > 4000 g. FWE by ultrasound systematically performed in the delivery room represents an independent and potentially modifiable risk factor for cesarean delivery.