A cumulative embryo scoring system for the prediction of pregnancy outcome following intracytoplasmic sperm injection.

INTRODUCTION

The ability to select the embryos that would lead to pregnancy would help to reduce multiple pregnancy rates. The objective was to evaluate the use of a cumulative embryo scoring system (CES) based on a five-point embryo scoring system for the prediction of pregnancy outcome following intracytoplasmic sperm injection (ICSI).

METHODS

A retrospective cohort study was performed on 364 triple embryo transfers from fresh ICSI cycles only. Embryo quality was assessed using a five-point scoring system. The CES was the summation of the individual scores. For the purpose of analysis, these were categorised into three groups: CES group one (score 9-10), CES group two (score 11-13) and CES group three (score 14-15). Main outcome measures were clinical pregnancy, implantation, live-births and multiple birth rates.

RESULTS

There was a trend towards better outcome with increasing CES scores. This trend was significant with CES groups one, two and three, corresponding with increasing pregnancy rates (30.3 vs. 45.1 vs. 51.7 percent), increasing implantation rates (12.4 vs. 20.5 vs. 21.8 percent), and increasing live-birth rates (12.4 vs. 26.4 vs. 31.0 percent). Age was also a significant independent predictor of clinical pregnancy. However, only CES group score was significant in predicting live-births, while age was significant in predicting multiple births.

CONCLUSION

CES based on the proposed five-point scoring system is useful for the prediction of pregnancy outcome in triple embryo transfers. In younger patients, a policy of transferring fewer embryos to reduce multiple births should be adopted.