title: A 29-gauge atraumatic needle for amniocentesis.
abstract: To compare perforation characteristics of standard 22 G (0.7 mm) to 29 G needle (0.34 mm) for amniocentesis.
  
  
  
  Seventeen human chorio-amnion membranes were perforated immediately after cesarean section using 22 G needle for spinal anesthesia and 29 G "pencil-point" needles for amniocentesis under in-vitro conditions. Area of perforation was determined using a microscope and volume of fluid leakage was measured over a period of 5 min.
  
  
  
  Membrane perforation with the 22 G needle resulted in a mean damaged area of 225,147.4 μm(2), a hole with a mean area of 50,154 μm(2) and amniotic fluid volume passage of 17.5 mL/5 min, whereas the 29 G needle generated a mean damaged area of 114,812.4 μm(2), a hole with an average area of 1382.5 μm(2) and volume passage of 0.28 mL/5 min. These differences were significant.
  
  
  
  The hole formed by membrane perforation with 29 G "pencil-point" needle for amniocentesis is 36 times smaller, and the amniotic fluid loss is 61 times less than that measured with the 22 G standard needle for spinal anesthesia. Significant reduction of complications following amniocentesis is expected with the 29 G needle.
authors.affiliation: University Clinic of Obstetrics and Fetal Medicine, University Medical Center Halle (Saale) of Martin Luther University of Halle-Wittenberg, Germany. michael.tchirikov@uk-halle.de
authors.forename: Michael
authors.initials: M
authors.lastname: Tchirikov
authors.forename: Georgios
authors.initials: G
authors.lastname: Gatopoulos
authors.forename: Joscha
authors.initials: J
authors.lastname: Steetskamp
authors.forename: Ulf-Rüdiger
authors.initials: UR
authors.lastname: Heinrich
authors.forename: Jürgen
authors.initials: J
authors.lastname: Brieger
authors.forename: Kristina
authors.initials: K
authors.lastname: Heidner
authors.forename: Heinz
authors.initials: H
authors.lastname: Koelbl
mesh_terms: D000649:Amniocentesis / Q000009:adverse effects / Q000295:instrumentation*; D000650:Amnion / Q000293:injuries; D002823:Chorion / Q000293:injuries; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D011247:Pregnancy; D013594:Syringes