A new guidance system for freehand, obstetric ultrasound-guided procedures.

OBJECTIVE

To assess the performance of the UltraGuide 1000 system, and to compare ultrasound-guided freehand mid-trimester amniocentesis with and without the new guidance system.

METHODS

One hundred and sixty-nine women referred for mid-trimester genetic amniocentesis were divided into two groups: a control group of 99 women who underwent the procedure by the freehand technique with scored needles and 70 patients who had the procedure carried out with the aid of a guidance system (UltraGuide 1000) with non-scored needles. The procedures were compared for duration, number of punctures and repositionings of the needle, the visibility of the needle during the puncture and the number of bloody taps.

RESULTS

The study group had significantly lower rates of reinsertion (none vs. 7.1%), repositioning (7.1% vs. 17.7%), bloody taps (none vs. 6.1%), touching the fetus (5.7% vs. 22.2%) and prolonged duration of the procedure (4.3% vs. 14.4%) compared with the control group. There was one fetal loss in the control group. Non-visibility of the needle before reaching the amniotic sac occurred in 18.6% of cases in the study group and in 38.4% of cases in the control group.

CONCLUSIONS

The new guidance system combines the benefits of an attached guide with the flexibility of the 'freehand' technique. Use of the new guidance system for mid-trimester genetic amniocentesis increases needle visibility and lowers the incidence of common complications.