Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system

Abstract

Recently, in-vitro maturation (IVM) of immature human oocytes recovered from non-stimulated follicles has been applied in the treatment of infertility. However, in previous reports, very few embryos cultured in conventional medium have reached the expanded blastocyst stage following in-vitro maturation and fertilization (IVM/IVF). The objective of this study was to investigate whether the developmental competence of human embryos following IVM/IVF could be enhanced by the use of a human ampullary cell co-culture system. Immature human oocytes were aspirated from small follicles at Caesarean section and then cultured in medium containing human menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes were randomly cultured either in conventional culture medium alone or in the co-culture system. Of 48 embryos cultured in conventional medium alone, all arrested at the 2-16-cell stage on day 3 after insemination. Of 46 embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at the 2-16-cell stage. Six embryos (13%) developed to the morula stage. Fourteen embryos (30.4%) developed to expanded blastocysts and two blastocysts were hatching on day 7 after insemination. We conclude that co-culture significantly enhances the development of blastocysts in embryos resulting from IVM/IVF.

Sterile filtered paraffin oil supports in vitro developmental competence in bovine embryos comparable to co-culture

“…In general, somatic cell co-culture is one method for overcoming the in vitro developmental block of cultured mammalian embryos. In a report by Yuh-Ming Hwu et al (6), co-culture cells may secrete embryotrophic factors such as growth factors, cytokines or oviduct-specific glycoproteins. In our study, the best regime for in vitro bovine embryo development is the use of paraffin oil plus co-culture (SPO + CC).…”

“…Researchers have optimized culture systems for various embryo stages and species (4)(5)(6), thus advancing in vitro culture technology for blastocyst development. The most commonly used culture environment has been the micro drop culture method using oil rather than large scale medium, with the exception of certain specific culture methods.…”

Pregnancies and deliveries after transfer of human blastocysts derived from in vitro matured oocytes in in vitro maturation cycles

“…However, only one of six embryos produced in that case report was competent to develop to the blastocyst stage. Hwu et al (10) reported that embryos derived from IVM oocytes when cultured in human tubal fluid alone arrest at the cleavage stage. However, 30% of 2PN embryos developed to blastocyst when embryos were cocultured with human ampullary cells.…”

In vitro maturation of human oocytes for assisted reproduction

“…Other studies also have suggested that the competence of immature oocytes is independent of the time of retrieval relative to the menstrual cycle (3,73,74). In a case series report, Chian et al (55) described performing natural-cycle IVF of the mature oocyte retrieved in combination with IVM of any immature oocytes retrieved during the same procedure for patients who previously had failed conventional IVF or IUI treatment.…”