A RETROSPECTIVE ANALYSIS OF THE IN-VITRO DEVELOPMENT OF SPARE HUMAN IN-VITRO FERTILIZATION PREIMPLANTATION EMBRYOS USING IN-HOUSE PREPARED MEDIUM AND MEDI-CULT COMMERCIAL MEDIUM

In-house prepared medium was used routinely in our in-vitro fertilizat ion (IVF) facility prior to the introduction of the commercial 'Medi-C ult' products, A comparative study of the in-vitro development of embr yos cultured in two [T6 and Earle's balanced salt solution (EBSS)] hum an-inactivated serum (HIS)-supplemented media from days 0 to 5 showed that 44.7% (46/103) of the embryos developed to the blastocyst stage i n the T6 medium compared with 22.3% (23/103) in EBSS, Following the in troduction of the commercial Medi-Cult IVF M2 medium, which is used ro utinely to culture fertilized eggs from days 0 to 2, new baseline data were required for the in-vitro development of 'spare' embryos from da ys 2 to 5, When Medi-Cult M3 medium was used, 35.6% (37/104) of the 's pare' day 2 embryos achieved the blastocyst stage. How ever, if morpho logically similar (four normal nucleated blastomeres with no fragmenta tion) day 2 embryos were selected, an increase in the blastocyst rate to 50.0% (33/66) was achieved, This compared favourably with the 45.0% blastocyst rate (published in the Medi-Cult literature) for M2/M3 med ium cultured human embryos, A small series of experiments with T6 + HI S medium and human serum albumin (HSA)-supplemented Ham's F-10, MCDB 3 02 and M3 media was undertaken to identify a suitable medium which cou ld be used for the culture of M2 medium day 2 embryos, Results show th at M2 medium cultured embryos placed in Ham's F-10 medium supplemented with 10 mg/ml HSA gave an acceptable 37.8% (14/45) blastocyst rate, T herefore, this medium could be substituted for M3 medium in an emergen cy, A total of 483 IVF embryos donated by patients, which were surplus to the therapeutic IVF programme, were used for these studies over a period of 30 months, Late day 2 IVF spare embryos were assigned an emb ryo score based on a high-power phase-contrast microscopic examination prior to being placed in culture. The embryo score provides an effect ive in-vitro parameter with which embryos from different patients can be compared, The cleavage and development of individual embryos were m onitored on days 2 to 5, In some cases, the continuing normal developm ent and viability of the day 5 cultured embryo were assessed by monito ring the hatching, attachment and outgrowth of the cavitated blastocys t.