Long-term follow-up after quinacrine sterilization in Vietnam. Part I: interim efficacy analysis.

OBJECTIVE To determine the long-term efficacy of nonsurgical sterilization with quinacrine. DESIGN Observational cohort study. SETTING Rural provinces in northern Vietnam. PATIENT(S) Two thousand seven hundred and nine women who had quinacrine insertions between 1989 and 1993. INTERVENTION(S) Interviews in 1994, 1995, and 1996 and review of available medical records. Pregnancy rates were corrected for problems in detecting and confirming pregnancies. MAIN OUTCOME MEASURE(S) Pregnancy rates. RESULT(S) Over 90% of women were interviewed at least once. Uncorrected cumulative pregnancy rates were 12.9% at 5 y after two insertions and 27.3% after one insertion. Effectiveness varied by age group: the partially corrected pregnancy rates after two insertions were 6.8% in women 35 or older at the time of insertion and 13.0% in women under 35. A subgroup of women who received oral papaverine at the time of quinacrine insertion had lower pregnancy rates, with a cumulative uncorrected rate of 5.3% at 4 years among women of all ages. CONCLUSION(S) Efficacy of quinacrine appears reasonable for two insertions of quinacrine in women 35 and older. It may be possible to improve efficacy by the use of papaverine or the Hieu insertion technique.