Assisted hatching with or without bovine oviductal epithelial cell co-culture for poor prognosis in-vitro fertilization patients.

Older patients and those who consistently return for embryo transfer but without implantation were studied to see if a combination of day 3 assisted hatching and co-culture (AH+CC) might be beneficial compared to assisted hatching alone (AH-alone). Female patients of > or = 38 years and couples who had previously failed to implant embryos three times or more were prospectively and randomly assigned to either an experimental or a control group. In the experimental group all embryos were co-cultured on partial monolayers of bovine oviductal epithelial cells for 2 days followed by assisted hatching by zona drilling (AH+CC). All control embryos were cultured by standard procedures until day 3 when they also underwent zona drilling prior to uterine transfer (AH-alone). With 50 cycles in each group there was unfortunately a marginal bias against the AH+CC group in that these patients had undergone a higher number of previous transfer cycles. There was a marginally lower percentage of fragmentation and a significantly higher degree of zona thickness variability in the AH+CC embryo group. Embryonic implantation was significantly increased (P < 0.05) in the AH+CC group (18%) when compared to the AH-alone group (10%). This difference was reflected in a significantly higher (P < 0.05) initial pregnancy rate (52 versus 32%) in the AH+CC group, and a higher (not significant) viable pregnancy rate (38 versus 22%).