Multifetal pregnancy reduction (MFPR) appears to be an efficacious method for improving the perinatal outcome of ‘high order’ multifetal gestations. The present study was undertaken to evaluate pregnancy outcomes after MFPR to twins in comparison with spontaneously conceived twins. In all, 10 patients with quadruplet gestations (group 1) and 30 patients with triplet gestations (group 2), who underwent MFPR to twins, were prospectively enrolled. Pregnancy complications, gestational age at delivery, mode of delivery and birthweights were compared with 30 consecutive spon-taneous twin gestations (group 3) matched by maternal age and parity. Mean gestational age at delivery and mean birthweights were significantly lower in group 1, compared with groups 2 and 3 (33.2, 35.9, 36.9 weeks, and 1843, 2209, 2361 g respectively). The incidence of pregnancy complications was significantly higher in group 1 compared with group 3. There was also a clear trend of increased incidence of specific pregnancy complications in group 1 compared with groups 2 and 3, especially premature contractions (PMC; 50, 27 and 13% respectively), and pregnancy-induced hypertension (PIH; 40, 23 and 7% respectively). In conclusion, the initial number of fetuses before reduction was inversely correlated with gestational age at delivery and birthweight, and positively correlated with pregnancy complications. Contrary to previous studies, we found a higher incidence of pregnancy complications after MFPR compared with spontaneous twins, especially PMC and PIH.