The factors affecting the procedure time during second trimester genetic amniocentesis: retrospective analysis

Abstract

Objective: Genetic amniocentesis is a method of prenatal diagnosis which is still the most commonly performed procedure today. The aim of this retrospective observational study was to analyze the factors affecting the duration of second trimester genetic amniocentesis. Methods:We evaluated the files of 117 patients in the study who undergone second trimester amniocentesis for genetic diagnosis. The duration that the amniocentesis needle was inside the uterine cavity and the duration of total procedure were both recorded and the correlation of these parameters with clinical and demographic characteristics was evaluated. For each patient, the indications for the procedure and clinical information were also registered. Results:The mean±SD values of 117 patients for age and the weeks of gestation were 31.7±5.4 years and 18.4±1.7 weeks, respectively. The mean±SD values of the time the amniocentesis needle was inside the uterine cavity and the total procedure time were 85.3±59.3 and 118.7±79.5 seconds, respectively. While there was no difference among the operators in terms of the duration that the amniocentesis needle was inside the uterine cavity (p=0.079), the total procedure durations were statistically different (p=0.004). The procedure was significantly longer in patients with vaginal bleeding prior to amniocentesis than in patients without vaginal bleeding before the procedure (115.0 vs 74.8 s; p=0.030). Both the appearance of the needle tip on ultrasound and the difficulty degree of procedure felt by the operators were found to have a significant impact on the duration of the procedure (p values were 0.024 and 0.030, respectively). Conclusion:The results of this study objectively show that second trimester genetic amniocentesis is a relatively short procedure. The difficulty degree of the procedure, the appearance degree of the needle tip on ultrasound and the presence of vaginal bleeding prior to the procedure affect the duration of the procedure. A larger scale prospective study is needed on the subject.