EFFICACY OF 2ND-TRIMESTER SELECTIVE TERMINATION FOR FETAL ABNORMALITIES - INTERNATIONAL COLLABORATIVE EXPERIENCE AMONG THE WORLDS LARGEST CENTERS

OBJECTIVE: Our goal was to develop the most comprehensive database pos sible to counsel patients about selective termination for fetal abnorm alities, because no one center has sufficient data to assess much more than crude loss rates. STUDY DESIGN: A total of 183 completed cases o f selective termination from 9 centers in 4 countries were combined (1 69 twins, 11 triplets, 3 quadruplets). Variables included indications, methods, (potassium chloride, exsanguination, air embolus), gestation al age at procedure, pregnancies lost (less than or equal to 24 weeks) , gestational age at delivery, and neonatal outcome. RESULTS: Indicati ons for selective termination were 96 chromosomal, 76 structural, and 11 mendelian. Selective termination was technically successful in 100% of cases. In 23 of 183 (12.6%) miscarriage occurred before 24 weeks; 2 of 37 (5.4%) occurred when the procedure done at less than or equal to 16 weeks and 21 of 146 (14.4%) when it was done thereafter. Air emb olization had a higher loss rate: 10 of 24 (41.7%) compared with 13 of 156 (8.3%) by potassium chloride (chi(2) = 117, P < 0.0001). Three ca ses of selective termination performed in monochorionic pregnancies al l resulted in pregnancy loss. Among 183 potentially viable deliveries, 7 occurred before 28 weeks, 19 at 29 to 32 weeks, 41 at 33 to 36 week s, and 93 at greater than or equal to 37 weeks. Gestational age at del ivery was not influenced by the technique used or the indication but w as negatively correlated with gestational age at the time of selective termination. No coagulopathy or ischemic damage was observed in survi vors. There was no maternal morbidity. CONCLUSIONS: (1) Selective term ination in experienced hands for a dizygotic abnormal twin is safe and effective when done with potassium chloride. A total of 83.8% of viab le deliveries occurred after 33 weeks and only 4.3% at 25 to 28 weeks. (2) Gestational age at the procedure correlated positively with loss rate and inversely with gestational age at delivery; this emphasizes t he need for early diagnosis in multifetal pregnancies. (3) Coagulopath y tests are probably unnecessary.