Embryoscopy: new developments in prenatal medicine.

Embryoscopy is a new technique that allows direct visualization of the embryo/fetus as early as the first trimester. A rigid fiberoptic endoscope is passed transcervically into the extracoelomic cavity and has been utilized to identify developmental milestones from weeks 4 to 8 following conception. All major external and internal structures develop during this period. With this technique, it is possible to both identify anomalies and confirm those diagnosed by ultrasound. Fetal blood sampling has also been preformed utilizing this technology and has established the feasibility of access to the human embryonic circulation. Future applications for embryoscopy include first-trimester prenatal diagnosis and therapeutic interventions such as gene or cell therapy at a time when the embryo is immunologically tolerant.