Pregnancy Outcome after Multifetal Pregnancy Reduction of Triplets to Twins versus Reduction to Singleton

Introduction: Multifetal pregnancy reduction (MPR) of triplets to twins results in improved pregnancy outcome compared with triplet gestations managed expectantly. However, it is not clear whether reduction to singleton may further improve pregnancy outcome.

Aim: To determine the rate of pregnancy complications and perinatal outcomes of MPR from triplets to twins versus reduction from triplets to singleton.

Methods: 277 triplet pregnancies underwent abdominal MPR at 11-14 weeks’ gestation. Cases were divided into two groups according to the final number of embryos: group A, reduction to twins (n=225) and group B, reduction to singleton (n=52).

Results: Triplet pregnancies reduced to twins delivered earlier (36 vs. 39 weeks’ gestation, P<0.001) with lower median birth weight (2,160g vs. 2,820g, P<0.001) and higher incidence of cesarean section (71.4% vs. 32.0%, p<0.001) compared with triplets reduced to singleton. The rates of preterm delivery were significantly higher in group A compared with group B prior to 37 weeks (56.4% vs. 16.3%, p<0.001), 34 weeks (20.2% vs. 4.1%. p=0.007) and 32 weeks’ gestation (9.6% vs. 0.0%, p=0.018). We did not find a significant difference in the rate of pregnancy loss before 24 weeks’ gestation (5.8% vs. 1.8%, p=0.12). Both groups had comparable neonatal outcomes, except for higher rates of NICU admission (33.0% vs. 8.2%, p<0.001) in group A.

Conclusions: Reduction of triplet pregnancies to singleton is associated with a lower risk of prematurity and superior perinatal outcomes. The option of reduction to singleton should be considered in cases where the risk of prematurity seems exceptionally high.