Blastocyst transfer for multiple prior IVF failure: a five year descriptive study

Abstract

Patients with recurrent IVF failure are generally regarded as having a poor prognosis, and when female age exceeds 35 yrs such patients face a particularly bleak outlook. This study reported on blastocyst transfer (BT) performed over a five-year interval in patients seeking "second opinion" after multiple failed IVF cycles. Clinical features and reproductive outcomes were compared between two sets of poor-prognosis IVF patients undergoing BT for the first time, the initial group underwent treatment in 2002 (n=66) and a second group presented five years later (n=392). The two clinical sets had no patients in common. The 2002 group had an average of 3.5 (+/- 1.1) prior failed IVF cycles at baseline, and mean (+/- SD) patient age was 36.4 (+/- 3.9) yrs. Average number of oocytes retrieved in this group was 10.4 (+/- 5.3) with a fertilisation rate of 58.8%. Although embryo arrest resulted in no transfer for 19 patients (28.8%), clinical pregnancy was achieved for 59.6% of transfers. Five years later, 392 patients underwent BT, but this group had an average of 4.5 (+/- 2.3) prior failed IVF cycles. Mean (+/- SD) female age was 36.0 (+/- 3.9) yrs, and the average number of oocytes retrieved in this group was 9.1 (+/- 5.4); the fertilisation rate was 59.5%. No blastocysts were available for transfer in 99 cases (25.3%); clinical pregnancy was achieved for 50.0% of transfers. The number of blastocysts transferred was similar in the two groups (1.6 vs. 1.3; p=0.06); the twinning rate rose slightly from 8.2% to 15.1% (p=0.12) despite an increased utilisation of single embryo transfer in 2007 (19.7% vs. 22.2%; p=0.40). Comparisons from 2002 and 2007 found no important differences between the two patient groups, except for a significantly higher rate of prior failed cycles in the 2007 group (p<0.001). This refractoriness was accompanied by a somewhat reduced blastocyst cryopreservation rate in 2007, compared to 2002 (27.6% vs. 29.5%; p=0.44). Clinical pregnancy rates are not adversely affected by application of BT in patients with multiple prior unsuccessful IVF cycles. For these patients, our data suggest that extended embryo culture and BT should be considered. Further controlled studies are needed to document more precisely the role of BT in this sub-set of refractory IVF patients.