Embryoscopy and fetoscopy are sometimes referred to as embryofetoscopy.  Embryofetoscopy is capable of providing knowledge about embryonic development as well as provide a method for prenatal investigation of high-risk pregnancies for recurrent genetic disorders, perform fetal intravascular transfusions, and  allow access to the embryo circulation [1,2].  Embryoscopy refers to visualization of the embryo 5 to 8 weeks after conception, while fetoscopy deals with visualization of the fetus 8 weeks following gestation.  Both procedures are performed via insertion of a high-resolution fiber-optic scope transadbominally or transcervically, either into the extracelomic space (before 11 weeks after conception) thus allowing visualization of the embryo through an intact amnion membrane,  or into the amniotic cavity (after 11 weeks)  [1].  A typical endoscope can vary from 1.7mm to 3.5mm in diameter and 0 to 30° in lens angle and is passed using ultrasound guidance [1].  Zero degree endoscopes are also used with resolution up to 50,000 pixels [3] (Figure 1).

            Figure 2:  Schematic diagram of an embryoscope inserted transcervically                                                                                                                                         and passed through the chorion into extraoelomic space [2]
Figure 1:  Embryoscope [3]

Once the scope reaches the opaque chorion, a rapid blunt thrust by the tip of the  endoscope has to be applied perpendicular to the chorionic membrane to allow penetration  into the extracoelomic space (Figure 2) [2].  This procedure has to be performed very  carefully to avoid areas of amnion and chorion juxtaposition as well as the placenta [2].   Consequently, phenotypical properties of the fetus such as head, face, dorsal and ventral  walls, umbilical cord and yolk sac can be observed.  Video recording through the scope  can also be done for more thorough examination at a later date.