PURPOSE: Childbearing delay contributes to the increase of subfertile couples that require assisted reproductive technology (ART). Subfertility relates with reproductive aging (RA). In vitro aging (IvA) (due to extended culture) may also impair oocyte competence. Aims of this study were to evaluate and compare the oocyte ultrastructure after RA and IvA. METHODS: Cumulus-oocyte complexes (COCs) (n=68), with metaphase II oocyte and expanded cumulus, from consenting patients (<35years old and ≥35years old, n=36), were selected by phase contrast microscopy and fixed at pick up, or after 24h culture. COCs (n=44) were studied by light and qualitative/morphometric transmission electron microscopy. Two-way ANOVA, with age and culture as grouping factors, was applied for statistical analysis (p<0.05). Metaphase II cumulus-free oocytes (n=24) were selected for confocal microscopy observations. RESULTS: Significant decrease of mitochondria-smooth endoplasmic reticulum aggregates, increase of mitochondria-vesicle complexes size and amount, decrease of cortical granules and microvilli, and alterations of the spindle structure characterized both RA and IvA oocytes. These changes were significantly more evident in the RA oocytes submitted to IvA. RA oocytes also showed changes of the zona pellucida and occurrence of vacuoles after culture. Cumuli appeared re-compacted after culture, irrespective of the age of the patients. CONCLUSIONS: These data demonstrated that aging is related to decay of oocyte ultrastructural quality, and that oocytes from elder women are more sensitive to prolonged culture (IvA) than the oocytes from younger women. These morphological results should be considered when applying ART in aged patients, rescue ICSI, or artificial oocyte activation.

Ultrastructural markers of quality are impaired in human metaphase II aged oocytes: a comparison between reproductive and in vitro aging / Bianchi, S; Macchiarelli, G.; Micara, Giulietta; Linari, Antonella; Boninsegna, Claudia; Aragona, Cesare; Rossi, G.; Cecconi, S.; Nottola, Stefania Annarita. - In: JOURNAL OF ASSISTED REPRODUCTION AND GENETICS. - ISSN 1058-0468. - STAMPA. - 32:9(2015), pp. 1343-1358. [10.1007/s10815-015-0552-9]

Ultrastructural markers of quality are impaired in human metaphase II aged oocytes: a comparison between reproductive and in vitro aging

MICARA, Giulietta;LINARI, Antonella;BONINSEGNA, CLAUDIA;ARAGONA, Cesare;NOTTOLA, Stefania Annarita
2015

Abstract

PURPOSE: Childbearing delay contributes to the increase of subfertile couples that require assisted reproductive technology (ART). Subfertility relates with reproductive aging (RA). In vitro aging (IvA) (due to extended culture) may also impair oocyte competence. Aims of this study were to evaluate and compare the oocyte ultrastructure after RA and IvA. METHODS: Cumulus-oocyte complexes (COCs) (n=68), with metaphase II oocyte and expanded cumulus, from consenting patients (<35years old and ≥35years old, n=36), were selected by phase contrast microscopy and fixed at pick up, or after 24h culture. COCs (n=44) were studied by light and qualitative/morphometric transmission electron microscopy. Two-way ANOVA, with age and culture as grouping factors, was applied for statistical analysis (p<0.05). Metaphase II cumulus-free oocytes (n=24) were selected for confocal microscopy observations. RESULTS: Significant decrease of mitochondria-smooth endoplasmic reticulum aggregates, increase of mitochondria-vesicle complexes size and amount, decrease of cortical granules and microvilli, and alterations of the spindle structure characterized both RA and IvA oocytes. These changes were significantly more evident in the RA oocytes submitted to IvA. RA oocytes also showed changes of the zona pellucida and occurrence of vacuoles after culture. Cumuli appeared re-compacted after culture, irrespective of the age of the patients. CONCLUSIONS: These data demonstrated that aging is related to decay of oocyte ultrastructural quality, and that oocytes from elder women are more sensitive to prolonged culture (IvA) than the oocytes from younger women. These morphological results should be considered when applying ART in aged patients, rescue ICSI, or artificial oocyte activation.
File allegati a questo prodotto
File Dimensione Formato  
Bianchi_Ultrastructural_2015.pdf

solo gestori archivio

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 4.92 MB
Formato Adobe PDF
4.92 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11573/822988
Citazioni
  • ???jsp.display-item.citation.pmc??? 28
  • Scopus 50
  • ???jsp.display-item.citation.isi??? 48
social impact