The study analyzed 1,097 dichorionic (DC), 559 monochorionic without intervention (MC) and 204 monochorionic with intrauterine surgery (MCS) twin pregnancies, including 167 fetoscopic laser procedures and 37 selective reductions. The primary endpoint was objective-based survival (GCS): dual survival in DC and MC or intended survival after reduction; it was achieved in 99.0% DC, 98.4% MC and 79.9% MCS pregnancies. MCS was the strongest predictor of failure to achieve GCS (OR: 21.2, 95% CI: 10.5–42.6, p < 0.001), fetal weight discrepancy ≥ 25% another risk factor (OR: 2.0, 95% CI: 1.3–3.0, p = 0.001). Secondary endpoints included goal compliant week (GCW) achieved in 52.1% DC, 54.2% MC and 37.9% MCS, and goal compliant weight (GCWt) in 82.9% DC, 69.4% MC and 52.3% MCS. Failure to achieve GCW was associated with ≥ 25% weight discrepancy in DC and MC (OR: 2.9–3.1, p ≤ 0.002) and with MCS (OR: 1.66, p = 0.006); failure to achieve GCWt most with non-compliance in DC (OR: 7.2, p < 0.001). Pregnancies with weight discordance ≥ 25% delivered 12–19 days earlier with a newborn weight 680–800 g lower. Chorionicity, weight discrepancy, and fetal surgery independently affect survival, delivery, and neonatal growth.