Induction of ovulation in rabbits by pure urinary luteinizing hormone

Hemodynamic changes induced by urinary human chorionic gonadotropin and recombinant luteinizing hormone used for inducing final follicular maturation and luteinization

OBJECTIVE

To compare the safety of recombinant human luteinizing hormone (LH) with that of urinary hCG in terms of the hemodynamic changes when they are used to induce final follicular maturation in patients undergoing in vitro fertilization (IVF). A secondary end point was efficacy in terms of IVF outcome.

DESIGN

Prospective, randomized clinical trial.

SETTING

University teaching hospital.

PATIENT(S)

Thirty IVF patients.

INTERVENTION(S)

Ovarian stimulation was induced with FSH under pituitary suppression. Patients were randomized to receive either hCG or recombinant human LH as a trigger of oocyte maturation (5,000 IU) and for luteal phase support (5,000 IU, 2,500 IU, and 2,500 IU on the day of follicular aspiration, 2 days later, and 5 days later, respectively).

MAIN OUTCOME MEASURE(S)

Mean arterial pressure, cardiac output, peripheral vascular resistance, and serum levels of progesterone, plasma concentrations of aldosterone, norepinephrine, and plasma renin activity were measured in all patients on postovulatory day 7 of the spontaneous menstrual cycle preceding IVF (baseline) and 7 days after the hCG/recombinant human LH ovulatory injection during the IVF cycle.

RESULT(S)

Ovarian response and IVF outcome (pregnancy rate, 60%) were similar in both treatment groups. On the seventh day after hCG/recombinant human LH administration, the peripheral vascular resistance was significantly lower and serum progesterone concentrations significantly higher in the hCG group as compared with the recombinant human LH group. The percentage change from baseline values during IVF cycles in all hemodynamic and neurohormonal variables investigated was higher (albeit not statistically different) in the group treated with hCG vs. the group treated with recombinant human LH.

CONCLUSION(S)

Recombinant human LH is associated with less intense circulatory changes than hCG when it is given to induce final follicular maturation and luteal phase support in IVF procedures.

Recombinant-human luteinizing hormone (r-hLH) as ovulatory stimulus in superovulated does

PURPOSE

To study the effects of r-hLH as ovulatory stimulus in does.

METHOD

New Zealand does, 18 wk old, in estrus, received 25 IU of pregnant mare serum gonadotropin (PMSG) followed at 48 h either by 50 IU of r-hLH (n = 20) or hCG (n = 20) to induce follicular growth and ovulation. All does were previously artificially inseminated to avoid endogenous LH surge. Half of the animals receiving r-hLH (n = 10) or hCG (n = 10) were killed at 72 h after the hormone administration, and the remaining half were killed at 14 days. At 72 h the number of corpora lutea and preovulatory follicles was determined, and fertilization rate, embryo quality, degree of embryonic development, and oviductal transit were all assessed. On day 14 the number corpora lutea and implanted embryos were counted, and implantation rate was determined. Median and interquartile ranges were calculated for each parameter.

RESULTS

At 72 h the median for corpora lutea was 8 (7-10) in the r-hLH group vs 13 (10-14) in the hCG group (P = 0.009); preopvulatory follicles were 7 (6-10) vs 0 (0-0) (P = 0.0007); the percentage of good-quality embryos was 71.4% (54.5-75) vs 33.3% (25-37.5) (P = 0.001), for intermediate-quality embryos it was 25% (14.3-36.4) vs 33.3% (25-38.5), and the percentage of degenerated embryos was 0% (0-12.5) vs 33.3% (25-37.5) (P = 0.015), respectively. Fertilization rates were similar in both groups. Embryonic development was more homogeneous in the animals receiving r-hLH (8 to > or = 16 cells) compared to those receiving hCG (2 to > or = 16 cells). The median of embryos still in oviducts at 72 h was significantly higher in the hCG group [6 (4-13)] than in the r-hLH group [0 (0-4)] (P = 0.41). At 14 days the median of corpora lutea was higher in the hCG [12 (11-16)] than in the r-hLH group [10 (7-13)] (P = 0.008), but no differences were noted in the number of implanted embryos. Implantation rate was higher in the r-hLH group [100 (92.3-100)] than in the hCG group [87.5 (83.3-94.1)] (P = 0.056).

CONCLUSIONS

At the studied dose an ovulatory stimulus with r-hLH induced fewer follicles to ovulate than hCG. Recombinant-hLH produced superior embryo morphological quality, a more homogeneous degree of embryo development, and more synchronous embryo transit than hCG. In spite of the larger number of ovulations following hCG, subsequent events essential for pregnancy were higher with r-hLH, offsetting differences in terms of implanted embryos at 14 days of pregnancy.