Pécheux O, et al. - Based on observational epidemiological data, the Institute of Medicine (IOM) recommended a gestational weight gain for full-term twin pregnancies of 17–25 kg for normal Body mass Index patients’, and characterize its guidelines on during twin pregnancies as “provisional”. Researchers examined the IOM’s gestational weight gain guidelines for their optimacy for maternal and neonatal outcomes via retrospectively analyzing all consecutive twin pregnancies delivering two live births. Outcomes revealed better outcomes in correlation with adequate gestational weight gain. The IOM guidelines for twin pregnancy are thus identified as appropriate and are recommended to be used in routine practice.