The authors evaluate the efficacy and safety of fetoscopy on a series of 510 patients in which the procedure was carried out between the 18th and 20th week of gestation in order to obtain a suitable fetal blood sample for prenatal genetic diagnosis; the whole pregnancy could be completely followed up in them. The complication rate was low (1.7%) when the first attempt of fetoscopy was successful, but rose dramatically up to 17.9% on repeated attempts: however, they only amounted to 7.8% of all cases. The results of their study lead the authors to propose fetoscopy as a powerful, accurate and safe addition to the presently available diagnostic methods, provided it is performed by well trained fetoscopists, under aseptic conditions and local anaesthesia.