Evaluation of co-culture and alternative culture systems for promoting in-vitro development of mouse embryos.

The goal of this study was to compare mouse embryo development in a defined synthetic medium (human tubal fluid) against the same medium supplemented with a defined synthetic serum (SS), co-culture on human tubal epithelium (TECC), and culture on human fibronectin (FN) with and without SS. After 48 h, TECC, SS and FN + SS cultures demonstrated accelerated development with > 70% achieving > or = 8-cell stage. After 72 h, these culture conditions also significantly increased the proportion of embryos reaching the blastocyst stage but only TECC significantly increased the number of hatching blastocysts. Nuclei of the trophectoderm of unhatched and hatched blastocysts were stained with propidium iodide before fixing and labelling both the trophectoderm and inner cell mass with bisbenzimide. Blastocysts from the TECC contained a significantly higher total cell number (TCN) and trophectoderm and inner cell mass cell numbers than all other groups. These findings indicate equivalent improvements in mouse embryo development to the blastocyst stage in response to TECC, SS and FN and an enhanced number of cells and rate of hatching found only with TECC.

Effects of induced hyperprolactinemia on in vitro fertilization cycles.

OBJECTIVE: To investigate the effect of induced endogenous hyperprolactinemia on the luteinization process, as expressed by the shift in the P:E2 ratio after hCG injection in IVF cycles. PATIENTS AND INTERVENTIONS: Serum PRL, E2, and P levels were measured in 49 IVF patients (leuprolide acetate and hMG protocol) on the day of hCG injection. Estradiol and P also were measured on the day after hCG. Serum P:E2 ratios were calculated for two groups of patients; group I (control): PRL < or = 20 ng/mL (conversion factor to SI unit, 1.00); group II (hyperprolactinemia): PRL > 20 ng/mL. Estradiol and P also were measured in follicular fluid (FF) and the gamete performance was compared between groups. RESULTS: Data analysis showed no significant differences in the mean +/- SD serum peak E2 (pg/mL; conversion factor to SI unit, 3.671) between groups: group I, 1,769 +/- 843; group II, 2,333 +/- 1,194; the mean FF E2 (pg/mL) group I, 351 +/- 221; group II, 370 +/- 186; or the mean FF P (ng/mL; conversion factor to SI unit, 3.180) group I, 8,357 +/- 3,127; group II, 11,354 +/- 12,888. No significant differences were found between groups in the P:E2 ratios on days 1 or 2: group I, 78 +/- 48 and 209 +/- 137; group II, 70 +/- 47 and 224 +/- 197, respectively. The magnitude of the P shift also showed no significant difference between the two groups; the mean +/- SD shift in the P level was 2.9 +/- 2.2 for group I, and 4.3 +/- 5.1 for group II. The serum PRL level had no effect on the fertilization rate (60% for group I and 70% for group II) or on the pregnancy rate (17% for group I and 23% for group II). CONCLUSION: These findings suggest that mild endogenous hyperprolactinemia induced by ovarian stimulation does not affect granulosa cell luteinization and gamete performance in humans.

Umbilical waveform variations in the acutely distressed fetus: an experimental model in the fetal sheep.

In previous experimental studies on the pregnant ewe, umbilical arterial and venous waveform variations, produced by maternal aortic and umbilical cord occlusions of different degrees, were investigated in healthy fetuses (pH > 7.30). In our study, the fetal pH in 10 pregnant ewes was first brought down to below 7.20 with a preliminary series of maternal aortic and umbilical cord occlusions; then the 10 ewes were again submitted to a similar series of maternal aortic and umbilical cord occlusion. There were 24 experimental sessions with series of umbilical occlusions and 27 sessions with maternal aorta occlusions. The differences in waveform responses between these two types of fetuses are characteristic. The acidotic fetus produces more protracted drops in S, D, and venous velocity and, at the end of occlusion, the return to normal is slower with no reactive overflow waveform. In addition, there is a typical venous undulating pattern and no reappearance of blood flow velocity during the umbilical cord occlusion (always observed in healthy fetuses). Another important observation is that the fetal heart rate responses (bradycardia or tachycardia or no fetal heart rate variations) are more erratic in the acidotic fetus and do not relate to the intensity of the occlusion or to the fetal pH. The possible clinical implications of these experimental findings are discussed.