A comparative analysis of grade 1 and grade 2 water in the Tygerberg Hospital in vitro fertilisation programme

There are conflicting reports in the literature about the effect of the water source for growth and insemination media in an in vitro fertilisation (IVF) programme. A controlled trial was carried out in which two-cell mouse embryos were cultured in Ham F10 medium containing either grade 1 water (test group) or grade 2 water (control group). Of the two-cell embryos, 92.0% (69 of 75) in the test group and 91.8% (67 of 73) in the control group cleaved to the blastocyst stage (no statistically significant difference). On the basis of this experiment grade 2 water was used in the Tygerberg Hospital human IVF programme with good results. A continuing pregnancy rate of 23% per embryo transfer over a 1-year period is reported.