A new test for the assessment of sperm-zona pellucida penetration: relationship with results of other sperm tests and fertilization in vitro.
The spermatozoa of some patients attending for in-vitro fertilization (IVF) fail to penetrate the zona pellucida in vitro. A test has been devised to identify these cases. It is based on the number of spermatozoa penetrating into the zona pellucida, which were counted after removing spermatozoa bound to the zona surface by vigorous aspiration of each oocyte through a narrow gauge (120 microns) glass pipette. The oocytes were collected from 197 patients undergoing IVF treatment with their own gametes; 79 with no oocytes fertilized and 118 with some oocytes fertilized. Sperm motility, morphology and DNA normality (acridine orange stain) were also measured. The relationships between sperm test results and IVF rate were examined by logistic regression. The proportions of penetrated zonae, normal sperm morphology and normal DNA were the most significant factors related to IVF rate in the whole group. Also, in patients with > or = 30 spermatozoa bound per zona pellucida or with normal sperm morphology > or = 30%, the proportion of penetrated zonae and normal DNA were most significant. Oocytes from 42 patients who had zero fertilization and low sperm-zona binding (average, 2.2 spermatozoa/zona pellucida) were re-incubated with normal donor spermatozoa: large numbers of spermatozoa bound (average, 88 spermatozoa/zona pellucida) and each zona was penetrated by at least one spermatozoon. In conclusion, the percentage of zonae penetrated was the variable most significantly correlated with IVF rate. Penetration of the zona was also strongly related to fertilization rates in patients without defects of sperm morphology and sperm-zona binding.(ABSTRACT TRUNCATED AT 250 WORDS)
Liu
D Y
DY
University of Melbourne Department of Obstetrics and Gynaecology, Royal Women's Hospital, Victoria, Australia.
Baker
H W
HW
D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000503:physiopathology; D007248:Infertility, Male / Q000503:physiopathology; D008297:Male; D012044:Regression Analysis; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000502:physiology; D015044:Zona Pellucida / Q000502:physiology