Zona pellucida thickness variation and occurrence of visible mononucleated blastomeres in preembryos are associated with a high pregnancy rate in IVF treatment

• Published in: Journal of assisted reproduction and genetics Vol. 15; no. 2; pp. 70 - 75
• Main Authors: PALMSTIERNA, M, MURKES, D, CSEMICZKY, G, ANDERSSON, O, WRAMSBY, H
• Format: Journal Article
• Language: English
• Published: New York, NY Kluwer/Plenum 1998; Springer Nature B.V; Springer US
• Subjects: Biological and medical sciences; Birth control; Blastomeres; Clinical Assisted Reproduction; Gynecology. Andrology. Obstetrics; Infertility; Medical sciences; Pregnancy; Sterility. Assisted procreation; Zona pellucida; Human; Embryo; Prognosis; Assisted procreation; Germinal cell; Blastomere; Zona pellucida; Thickness; In vitro fertilization embryo transfer; Mononuclear cell; Morphology; Predictive value; Female; Oocyte
• ISSN: 1058-0468; 1573-7330
• DOI: 10.1007/BF02766828

Purpose: The ability of six morphological criteria (embryo development rate, fragmentation, regularity of blastomere shape, equality of blastomere size, zona pellucida thickness variation [ZPTV], and visible mononucleated blastomeres [VMBs]) to predict pregnancy in IVF treatment cycles was evaluated.Methods: In order to select a homogeneous study group, 85 consecutive nulliparous couples with single tubal infertility undergoing their first IVF treatment and receiving three preembryos at embryo replacement 2 days after ovum pickup were included.Results: A total of 255 preembryos was replaced two days after ovum pickup and resulted in 34 clinical pregnancies (40%). By logistic regression analysis, ZPTV and VMBs showed highly significant and strong predictive values, whereas none of the other parameters was a significant predictor of pregnancy. In the treatments in which all replaced preembryos had a ZPTV of less than 15%, the pregnancy rate was extremely low (1/22). If the maximum ZPTV of any of the replaced preembryos was in the interval between 15 and 20%, the pregnancy rate was 24.1% (7/29). In the treatments in which at least one preembryo had a ZPTV of more than 20%, the pregnancy rate was 76.5% (26/34). When VMBs were added to the results of the ZPTV analysis, the pregnancy rate was as high as 92.3% (24/26).Conclusions: ZPTV and VMBs seem to be strong predictors of pregnancy in IVF treatment and thus important indicators of good embryo quality.