Amniocentesis after multifetal pregnancy reduction: Is it safe?

OBJECTIVE: This report reviews the obstetric outcomes of women with multife tal pregnancy reductions who subsequently underwent elective amniocentesis. STUDY DESIGN: Five hundred eight patients underwent multifetal pregnancy re duction at our institution. Among these, 91 patients underwent subsequent e lective amniocentesis. The obstetric outcomes of all 508 patients were foll owed up. By means of logistic regression we evaluated several variables to determine any association with loss rate: (1) the finishing number of fetus es, (2) the number of fetuses undergoing reduction (starting number of fetu ses minus the finishing number of fetuses), (3) the gestational age at redu ction, (4) the maternal age at reduction, and (5) the procedure protocol. W e observed that the finishing number of fetuses, the number of fetuses remo ved. and the procedure protocol were significantly associated with pregnanc y loss rate. Women who underwent subsequent amniocentesis were compared wit h those who did not undergo amniocentesis. By means of multivariate conditi onal likelihood analysis we stratified the two groups according to the prev iously mentioned significant variables to compare the pregnancy loss rates. RESULTS: Among patients who subsequently underwent elective amniocentesis t he total uncorrected pregnancy loss rate was 9.0% and the early premature d elivery rate was 4.5%. The number of fetuses removed, the finishing number of fetuses, and the procedure protocol were statistically significantly ass ociated with the loss rate. The adjusted odds ratio relating amniocentesis to the pregnancy loss rate was 0.7 (95% confidence interval, 0.31.5; P = .3 .) CONCLUSIONS: The uncorrected rates of pregnancy loss and of early premature delivery among patients with multifetal pregnancy reduction who underwent subsequent amniocentesis were comparable to those of patients with multifet al pregnancy reduction who did not undergo amniocentesis.