title: Safer cordocentesis by new 25-gauge needles.
abstract: OBJECTIVE
  The objective of this study was to establish safer cordocentesis by using newly produced 25-gauge needles rather than the needles currently used.
  
  
  METHODS
  Human umbilical cords were preserved in experiment 1. Pinching both ends, cordocenteses were performed by filling the cord with saline inside the sphere of the pressure-equilibrated Ringer's solution bag in an aquarium. Pressure alterations were recorded before and after the cordocenteses (n = 5 in each needle) using 22-, 23-, and 25-gauge needles. In experiment 2, human umbilical blood after delivery was preserved. Umbilical blood was drawn in syringes, and fixed in syringe infusion pumps of 150 ml/h. The blood (n = 8) was then pushed into the test tubes through 22-, 23-, and 25-gauge needles. Hemolysis and platelet activation were evaluated. As in the case of clinical data, non-stress tests (NST) subsequent to cordocenteses were compared between 23-gauge (n = 19) and 25-gauge (n = 16) needles.
  
  
  RESULTS
  In experiment 1, the 25-gauge cordocenteses documented a more favorable pressure curve than other needles. In experiment 2, no statistical significance was observed for plasma-free hemoglobin, total bilirubin, hemoglobin, AST, LDH, potassium, platelet count, beta-thromboglobulin, and platelet factor IV. As in the case of clinical data, NSTs subsequent to cordocenteses revealed strong significance in the duration to recover variability (p = 0.0003) and the duration to recover acceleration (p = 0.0033).
  
  
  CONCLUSIONS
  We concluded that 25-gauge needles appear superior in avoiding blood loss in the leaking phase. Although blood drawing takes time in the sampling phase, no hemolysis or platelet activation was observed. NST proved that 25-gauge cordocenteses showed favorable patterns. We propose that use of 25-gauge needles is promising under appropriate procedures in cordocentesis.
authors.affiliation: Department of Obstetrics and Gynecology, National Defense Medical College, Tokorozawa, Japan. grd1805@ndmc.ac.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsuda
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shibasaki
authors.forename: Masashi
authors.initials: M
authors.lastname: Yoshida
authors.forename: Kenichi
authors.initials: K
authors.lastname: Furuya