SERUM IS MORE EFFECTIVE THAN ALBUMIN IN PROMOTING HUMAN EMBRYO DEVELOPMENT AND IMPLANTATION

Objective: To compare the effects of serum with those of Albuminar-5 ( Armour Pharmaceutical Co., Eastbourne, Sussex, United Kingdom) as medi um supplements to Earle's balanced salt solution (EBSS) for NF and sub sequent-embryo development. Design: A retrospective study. Gametes and embryos from 318 patients were cultured in the presence of serum (gro up 1). Gametes and embryos from 130 patients were cultured in the pres ence of Albuminar-5 (group 2). Embryos obtained from IVF were replaced into the uterus within 48 hours after insemination. Surplus bipronucl eate embryos were cultured up to 14 days with either serum or Albumina r-5. Setting: Two tertiary referral fertility clinics; university teac hing hospital. Patients: Four hundred forty-eight patients with a wide spectrum of causes of subfertility, ranging in age from 24 to 43 year s. Main Outcome Measures: Fertilization rate, pregnancy rate (PR), imp lantation rate, and surplus embryo development in vitro. Results: The PR for group 1 patients was higher than that of group 2 (27.0% versus 15.4%, respectively). Although fertilization rates were identical in t he two groups, cumulative embryo scores and implantation rates were si gnificantly higher in group 1. There was no difference between the gro ups in age distribution, types of ovarian stimulation, numbers of pati ents with day 1 or day 2 transfers, or luteal phase support. Of 31 emb ryos cultured with serum, 54.8% reached the fully expanded blastocyst stage and 25.8% hatched. Of 19 embryos cultured with Albuminar-5, only 5.3% reached the fully expanded blastocyst stage and none hatched. Co nclusions: The results suggest that, under certain conditions, serum s upplementation yields better results than protein supplementation alon e. The latter may be suitable only in conjunction with additional comp onents.