In Vitro Fertilization of Human Follicular Oocytes by Trypsin‐Treated Spermatozoa

Abstract

In vitro fertilization of human follicular oocytes was carried out using trypsin-treated spermatozoa. The oocytes were recovered, from ovaries in situ by culdoscope with a special oocyte recovery apparatus: Using this apparatus, a total of 165 oocytes were recovered by aspirating 324 follicles from 80 patients (average 2.1 oocytes/patient). Degenerated oocytes (32) at the initial evaluation were not included in the experiment and the 61 remaining (45.9%) were matured in vitro. The matured oocytes were then inseminated by trypsin-treated or untreated spermatozoa at concentrations of 6 to 20 times 106 sperm/ml. Eighteen of 31 oocytes (58.1%) inseminated by trypsin-treated spermatozoa were fertilized and three (9.7%) of the fertilized oocytes developed to a blastocyst stage, whereas 6 out of 30 oocytes (20%) which were inseminated with non-treated spermatozoa were fertilized and none of them developed beyond a 16-cell stage. Therefore, it appears that trypsin-treatment may increase the fertilizing ability of human spermatozoa.