The effects of dibromochloropropane (DBCP) and ethylene dibromide (EDB) on the function and ultrastructure of freshly ejaculated washed ram spermatozoa were assessed. These two compounds inhibited the collective motility of the sperm in a dose-dependent fashion when the sperm cells generated their energy either by mitochondrial respiration (2-deoxyglucose-treated sperm cells) or by the intact energy production system. DBCP and EDB inhibited the oxygen uptake by the sperm in a dose-dependent manner. No change in lactic acid accumulation and glucose utilization by the sperm cells was noted following DBCP and EDB addition. No change in the collective motility of the sperm was noted when DBCP or EDB were added to spermatozoa treated with the electron transfer inhibitor, antimycin A. Electron microscopy studies of sperm cells treated with DBCP revealed lesions in the plasma membrane adjacent to the acrosome and in the acrosomal membrane forming vesiculations. The inner membrane and the matrix space of the mitochondria were condensed following DBCP treatment, leaving a large mitochondrial peripheral space, compared with the control. EDB, at the concentration studied, caused no change in the ultramorphological structure of the sperm. DBCP was more potent, at least 4-fold, compared with EDB. An in vitro direct effect of DBCP and EDB on ram spermatozoa was established. It is suggested that quantitative measurements of sperm collective motility derived by different metabolic pathways can be used as an in vitro toxicological model for evaluation of toxicological and environmental factors affecting biological systems.

RESULTS: Embryos with implantation had a shorter time from fertilization to 9 cell formation compared to embryos without implantation, which trended towards significance (66.4 vs. 73.3h, p¼0.081). When data was analyzed from time of PN fading, we observed the same results. When controlled for differences in patient age, AMH, and peak estradiol levels, we found a trend in delayed appearance of the blastocele in embryos that failed implantation (99 vs. 94h, p¼0.075). No statistical difference was observed in time to PN fading, 2, 3, 4, 5, 6, 7, or 8 cell and time from 2-3, 3-5, and 3-4, 5-8 cell. Embryos that implanted were associated with decreased oocyte age (35.57 vs 33.18yr, p¼0.0003), higher maternal AMH (4.41 vs. 2.87ng/mL) and higher peak estradiol levels (3010 vs. 2411pg/mL). A lower BMI trended towards, but did not reach, significance (21.82 vs. 26.86kg/m 2 , p¼0.0811). No difference was found when the annotator of the morphokinetics or patient diagnosis was analyzed.CONCLUSIONS: Implantation success of embryos undergoing IVF correlated with a trend in delayed time to 9 cell and blastocele appearance from PN fading or fertilization in embryos that failed to implant. Clinical factors favoring implantation included maternal factors of decreased oocyte age and increased ovarian reserve, consistent with previous reports. Much larger numbers will be forthcoming and needed to determine if morphokinetic parameters can aid embryo selection within subsets of age and ovarian reserve.