Effects of the timing of selective reduction and finishing number of fetuses on the perinatal outcome in triplets: a single-center retrospective study.

OBJECTIVE

This study aimed to evaluate the effect of the timing of selective reduction and finishing the number of fetuses on perinatal outcomes in triplets.

METHOD: The study assessed 417 cases of triplets. Perinatal outcomes were compared between selective reduction (SR) performed at 11-14+6 weeks of gestation and SR performed at 15-24+6 weeks of gestation for the same starting and finishing numbers of fetuses. Then, the perinatal outcomes of reduction to singletons and twins were compared for the same range of SR of gestational weeks.

RESULTS

The spontaneous abortion rate was 6.5% and 14.9%, respectively, when SR was performed at 11-14+6 weeks of gestation (214 cases) and at 15-24+6 weeks of gestation (94 cases) (p = .019). In total, 74 cases of triplets were reduced to singletons and 214 cases were reduced to twins when SR was performed at 11-14+6 weeks of gestation. Preterm labor rates, low birth weight rates, birth weights, and gestational ages at delivery also showed significant differences (p < .001). In total, 35 cases of triplets were reduced to singletons and 94 cases were reduced to twins when SR was performed at 15-24+6 weeks of gestation. The preterm labor rates, low birth weight rates, birth weights and gestational ages at delivery also significantly differed (p < .05).

CONCLUSIONS

When the starting and finishing numbers of fetuses were the same, the timing of SR could affect the spontaneous abortion rates. When the starting number of fetuses was the same, the timing of SR did not affect the neonatal outcome. However, the finishing number of fetuses was the influencing factor.