Development of a nonhuman primate model for fetoscopy.

Twenty-four fetoscopy procedures were performed on 22 monkeys (19 Macaca mulatta, one M. fascicularis, two Erythrocebus patas) with gestational ages ranging from 66 to 145 days. Insertion of the fetoscope without ultrasound guidance was easy in 14 and difficult in ten procedures. Amniotic fluid exchange with normal saline, to improve visualization, was successful in eight of 13 procedures. Fetal blood sampling was successful in four of nine attempts. Nine monkeys aborted within 17 days of the fetoscopy, the remaining 13 went to term or were used in other research protocols. Major complications included maternal hemorrhage into the amniotic fluid, inability to enter the amniotic cavity, and abortion. Maternal serum alpha-fetoprotein following fetoscopy was not a useful indicator of subsequent abortion.