The external appearance of a newborn baby can provide important clues for genetic syndromes or to confirm the likelihood of normal outcome. Much of the fetal anatomy can now be well described before delivery using 2-D, 3-D, and 4-D ultrasound. However, it is not always possible to satisfactorily visualize the fetus using non-invasive techniques because the quality of these images can be affected by fetal size, position, and movement.

Fetoscopy involves placement of a thin, flexible instrument into the uterus through a small trans-abdominal incision on the mother. The endoscope can also be used through the maternal cervix. This procedure is typically performed at approximately 18 weeks when many of the external fetal structures are more easily visualized. Occasionally, this technology can be also applied to the examination of first-trimester embryos.

Advances in laparoscopic and microsurgical techniques, with development of novel instruments, have extended the diagnostic capabilities of endoscopy to fetal therapy as well. Endoscopic procedures have been reported on the placenta, umbilical cord, and membranes. The same approach has also been used to treat congenital diaphragmatic hernia with fetal endotracheal occlusion (FETO), deliver laser ablation of abnormal vascular connections in twin-twin transfusion, and repair fetal bladder outlet obstruction.