Amniocentesis and chorionic villus sampling in twin gestations: which is the best sampling technique

OBJECTIVE: To compare the fetal loss rate <24 weeks and the preterm premature rupture of the membranes <34 weeks' gestation according to type of invasive procedure and to sampling techniques in twins. STUDY DESIGN: Retrospective cohort study of 204 twin pregnancies, who underwent amniocentesis (100) or chorionic villus sampling (104). RESULTS: Fetal loss rate <4 weeks was 3.85% in chorionic villus sampling group and 4.00% in amniocentesis group (P value not significant). According to sampling technique, fetal loss rate was 4.17% (chorionic villus sampling 1 puncture), 2.70% (amniocentesis 1 puncture), 3.75% (chorionic villus sampling 2 punctures), and 4.76% (amniocentesis 2 punctures), (P values not significant). Preterm premature rupture of the membranes rate <34 weeks was 8.2% chorionic villus sampling group and 10% in amniocentesis group (P value not significant). According to sampling technique, preterm premature rupture of the membranes rate was 12.5% (chorionic villus sampling 1 puncture), 8.1% (amniocentesis 1 puncture), 6.9% (chorionic villus sampling 2 punctures), and 11.1 % (amniocentesis 2 punctures), (P values not significant). CONCLUSION: Double entry technique does not affect significantly the outcomes evaluated, in both amniocentesis and chorionic villus sampling.