HIGH IMPLANTATION AND PREGNANCY RATES WITH TRANSFER OF HUMAN BLASTOCYSTS DEVELOPED IN PREIMPLANTATION STAGE ONE AND BLASTOCYST MEDIA

Objective: To evaluate the proficiency of preimplantation stage one (P 1) and blastocyst media in supporting human blastocyst development and to document implantation and clinical pregnancy rates from the transf er of the normally developed blastocysts. Design: Retrospective clinic al study. Setting: Private IVF unit of a university-affiliate center. Patient(s): Twenty-eight women aged 33.7 +/- 2.9 years who underwent I VF treatment for infertility. Intervention(s): Bipronucleate oocytes o btained from IVF and intracytoplasmic sperm injection were cultured in vitro with P1 and blastocyst media for 96-120 hours. One to three emb ryos were transferred (2.1 +/- 0.2 for the patients who became pregnan t and 1.5 +/- 0.3 for those who did not become pregnant). Main Outcome Measure(s): Total number and percentage of developed blastocysts, fre quency of blastocysts of grades A and B, and implantation and pregnanc y rates. Result(s): From 431 oocytes retrieved, 269 bipronucleate oocy tes were cultured, producing 81 blastocysts that resulted in the trans fer of 54 embryos in 27 procedures. Blastocysts developed in 39.7% +/- 5.5% of the pregnant group and 30.2% +/- 4.5% of the nonpregnant grou p. From 15 (15/27 = 55.6%) clinical pregnancies, 18 (18/54 = 33.3%) ge stational sacs were visualized. The rate of implantation in the pregna nt group was 58.1% (18/31). Conclusion(s): These results provide evide nce for the benefits of extending human embryo culture with P1 and bla stocyst media for all normally fertilized embryos in vitro. (Fertil St eril(R) 1998;70:659-63. (C) 1998 by American Society for Reproductive Medicine.).