Induced corpus luteum dysfunction after aspiration of the preovulatory follicle in monkeys

Hotspots and frontiers in luteal phase defect research: An in-depth global trend bibliometric and visualization analysis over a 52-year period

Luteal phase defect (LPD) is a common female reproductive endocrine defect，which is associated not only with certain diseases but also with the menstrual cycle and fertility in women. With the development of assisted reproductive technology (ART) in recent years, the incidence of luteal phase defect is high among patients using assisted reproductive technology. The aim of this study was to evaluate worldwide research on luteal phase defects using bibliometric analysis. A total of 631 documents related to the study of luteal phase defect were identified over the last 52 years. The current status and trend of globalization can be comprehended by analyzing the annual number of publications, institutions, authors, countries and regions of corresponding authors, journals, influential luteal phase defect publications (which were highly cited), highly cited references in luteal phase defect publications (cocitation analysis) and keywords. The study results provide a comprehensive overview of the development of scientific literature and are of great significance for the future development of the field，especially infertility and early pregnancy loss.

Ovarian stimulation for IVF and endometrial receptivity--the missing link

The contemporary approach to ovarian stimulation for IVF treatment results in supraphysiological concentrations of steroids during the follicular and luteal phases of the menstrual cycle. These sex steroids act directly and indirectly to mature the endometrium, influencing receptivity for implantation. Corpus luteum function is distinctly abnormal in IVF cycles, and therefore luteal support is widely used. Various reasons may underlie the defective luteal phase, including (i) ovarian hyperstimulation per se, (ii) gonadotrophin-releasing hormone (GnRH) analogue co-treatment and (iii) the use of human chorionic gonadotrophin (HCG) to induce final oocyte maturation. The recent introduction of GnRH antagonist co-treatment for the prevention of a premature LH rise during the late follicular phase allows for different approaches to ovarian stimulation for IVF. However, a recent meta-analysis showed that implantation rates may be compromised by using GnRH antagonists in currently employed regimens. The development of endometrium receptive to embryo implantation is a complex process and may be altered by inappropriate exposure to sex steroids in terms of timing, duration and magnitude. New approaches to the assessment of endometrial receptivity are now required. Novel approaches to ovarian stimulation aimed at adjusted GnRH antagonist regimens and achieving a more physiological luteal phase endocrinology are now appearing in the literature and may represent an important step in the improvement of the overall health economics of IVF.

Effect of follicular aspiration just before ovulation on corpus luteum characteristics, circulating progesterone concentrations and uterine receptivity in single-ovulating and superstimulated heifers

The aim of this study was to investigate, in unstimulated and superstimulated heifers, the effect of follicle aspiration just before ovulation on corpus luteum (CL) development, circulating progesterone (P4) concentrations and the ability of the uterus to support embryo development. Following follicle aspiration or ovulation timed from GNRH administration, CL development was assessed by daily ultrasonography, and CL function was assessed in terms of the capacity to produce P4 and the expression of genes involved in steroidogenesis in luteal tissue. The capacity of the uterine environment to support conceptus development was assessed following transfer and recovery of in vitro-produced embryos. Follicular aspiration just before the expected time of ovulation leads to a significant reduction in CL diameter, CL area and area of luteal tissue. This was associated with a decrease in circulating P4 in both unstimulated and superstimulated heifers. Follicle aspiration leads to a reduction in conceptus length and area on day 14 in unstimulated heifers only. Follicle aspiration leads to a reduction in the expression of LHCGR in luteal tissue from unstimulated heifers compared with those in which the CL formed after ovulation. Superstimulation significantly reduced the expression of STAR in luteal tissue in both ovulated and follicle-aspirated heifers. In conclusion, in stimulated and unstimulated heifers, aspiration of the preovulatory dominant follicle(s) just before expected ovulation interferes with the subsequent formation and function of the CL, in terms of size and P4 output and this, in turn, is associated with a reduced capacity of the uterus to support conceptus elongation in unstimulated heifers.

WITHDRAWN: Luteal phase support in assisted reproduction cycles

BACKGROUND

The aspiration of the granulosa cells that surround the oocyte and the use of gonadotropin releasing hormone agonists (GnRHa) during assisted reproduction technology (ART) treatment can interfere with the production, during the luteal phase, of progesterone, which is necessary for successful implantation of the embryo. Providing hormonal supplementation during the luteal phase with either progesterone itself, or human chorionic gonadotropin (hCG), which stimulates progesterone production, may improve implantation and, thus, pregnancy rates.

OBJECTIVES

To determine (1) if luteal phase support after assisted reproduction increases the pregnancy rate, (2) the optimal hormone for luteal phase support, i.e. hCG, progesterone, or a combination of both, and (3) the optimal route of progesterone administration.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group trials register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1971 to Dec 2003), EMBASE (1985 to Dec 2003). We handsearched reference lists of relevant articles were scanned, and abstract books from scientific meetings up to December 2003.

SELECTION CRITERIA

Randomized controlled trials of luteal phase support after ART treatment, comparing hCG or progesterone with placebo or no treatment, comparing progesterone with hCG, progesterone plus hCG, or progesterone plus estrogen, or comparing different routes of progesterone administration. Quasi-randomized trials were excluded from the main analyses, but included in a secondary analysis for each comparison.

DATA COLLECTION AND ANALYSIS

For each comparison, data on live birth, ongoing and clinical pregnancy per embryo or gamete transfer procedure, miscarriage per clinical pregnancy, ovarian hyperstimulation syndrome (OHSS) per transfer, and multiple pregnancy per clinical pregnancy were extracted into 2 x 2 tables and subgrouped by use of GnRHa in the ovarian stimulation regimen. The odds ratio (OR) and risk difference (RD) were calculated.

MAIN RESULTS

Fifty-nine studies were included in the review. Luteal phase support with hCG provided significant benefit, compared to placebo or no treatment, in terms of increased ongoing pregnancy rates (odds ratio (OR) 2.38, 95% confidence interval (CI) 1.32 to 4.29) and decreased miscarriage rates (OR 0.12, 95% CI 0.03 to 0.50), but only when GnRHa was used. The odds of OHSS increased 20-fold when hCG was used in cycles with GnRHa. Progesterone use resulted in a small but significant increase in pregnancy rates (OR 1.34, 95% CI 1.01 to 1.79) when trials with and without GnRHa were grouped together, but no effect on the miscarriage rate was observed. No significant difference was found between progesterone and hCG or between progesterone and progesterone plus hCG or estrogen in terms of pregnancy or miscarriage rates, but the odds of OHSS were more than 2-fold higher with treatments involving hCG than with progesterone alone(OR 3.06, 95% CI 1.59 to 5.86). Comparing routes of progesterone administration, reductions in clinical pregnancy rate with the oral route, compared to the intramuscular or vaginal routes, did not reach statistical significance, but there was evidence of benefit of the intramuscular over the vaginal route for the outcomes of ongoing pregnancy and live birth. No significant difference in pregnancy rate was observed between vaginal progesterone gel and other types of vaginal progesterone.

AUTHORS' CONCLUSIONS

Luteal phase support with hCG or progesterone after assisted reproduction results in an increased pregnancy rate. hCG does not provide better results than progesterone, and is associated with a greater risk of OHSS when used with GnRHa. The optimal route of progesterone administration has not yet been established.

Comparative study of the efficacy and tolerability of two vaginal progesterone formulations, Crinone⁎ 8% gel and Utrogestan† capsules, used for luteal support

OBJECTIVE

To compare the efficacy and tolerability of two different types of vaginal progesterone (P), Crinone 8% gel (Fleet Laboratories Ltd., Watford, United Kingdom) and Utrogestan capsules (Laboratories Besins International, Paris, France), used for luteal support after in vitro fertilization (IVF) cycles.

DESIGN

Cohort study.

SETTING

In Vitro Fertilization Polyclinic, Zagreb, Croatia.

PATIENTS

A total of 285 women aged < or =37 years undergoing IVF-embryo transfer treatment.

INTERVENTIONS

Patients were treated with either Crinone 8% vaginal P gel (90 mg) administered daily, or Utrogestan vaginal capsules (2 x 100 mg) administered three times daily. Progesterone was administered from the day of oocyte retrieval (day 0) to menses or, in a case of pregnancy, until week 12.

MAIN OUTCOME MEASURE

Clinical pregnancy rate. The tolerability and acceptability of both preparations were determined by a questionnaire given to patients.

RESULTS

The similar rates of clinical pregnancies (33.1% vs. 30.9%) [corrected] were obtained by using either Crinone 8% vaginal P gel or Utrogestan vaginal capsules. Overall tolerability and acceptability were significantly better in the Crinone group than in the Utrogestan group.

CONCLUSIONS

The efficacy of the two vaginal P formulations was nearly the same, but the tolerability and acceptability of Crinone 8% gel were superior, in the opinion of patients.

Impact of leuprolide acetate on luteal phase function in women undergoing controlled ovarian hyperstimulation and intrauterine insemination

OBJECTIVE

To determine if the combination of leuprolide acetate (LA) and human menopausal gonadotropin (hMG) results in luteal phase dysfunction.

DESIGN

A prospective, randomized clinical trial.

SETTING

A tertiary care university fertility center.

PATIENT(S)

One hundred thirty-five couples with various etiologies of infertility.

INTERVENTION(S)

Patients were prospectively randomized to receive either hMG and intrauterine insemination (IUI) or luteal phase down-regulation with LA, hMG, and IUI.

MAIN OUTCOME MEASURE(S)

Serum luteal phase progesterone (P) and luteal phase estradiol (E2) were obtained 9 days after hCG administration. Twenty-four-hour urinary P and luteinizing hormone (LH) were analyzed 9 days after human chorionic gonadotropin (hCG). Endometrial biopsies were performed 11 days after hCG and evaluated for luteal phase defects (LPD) using Noyes' criteria.

RESULT(S)

No significant differences in the incidence of LPD (11.9% vs. 13.9%), cycle fecundity (16.6% vs. 16.3%), or luteal phase hormone profiles were observed between the groups receiving and not receiving LA. A significant difference in E2 levels (on the day of hCG administration) between cycles with a luteal phase defect (967 pg/mL +/- 106) and without a luteal phase defect (1,422 pg/mL +/- 83) was observed (P<.05).

CONCLUSION(S)

Pituitary down-regulation with LA combined with hMG did not result in luteal phase dysfunction. The E2 levels on the day of hCG administration in both groups were lower in women with documented luteal phase defects.

Nonhuman primates contribute unique understanding to anovulatory infertility in women

Anovulatory infertility affects a large proportion of reproductive-aged women. Major improvements in successful clinical treatment of this prevalent disorder in women's health have been made possible because of biomedical research employing nonhuman primates. Experiments on female rhesus monkeys were the first to demonstrate that the key hypothalamic neurotransmitter, gonadotropin-releasing hormone, involved in stimulating pituitary gonadotropin synthesis, storage, and release was bioactive only when released in approximately hourly bursts. This breakthrough in understanding gonadotropin regulation enabled identification of hypogonadotropic, apparently normogonadotropic, and hypergonadotropic forms of anovulatory infertility, and development of appropriate stimulatory or inhibitory gonadotropin therapies. Treatments to overcome anovulatory infertility represent one of the major advances in clinical reproductive endocrinology during the last 25 yr. The future promise of nonhuman primate models for human ovulatory dysfunction, however, may be based on an increased understanding of molecular and physiological mechanisms responsible for fetal programming of adult metabolic and reproductive defects and for obesity-related, hyperinsulinemic impairment of oocyte development.

Luteal phase support in assisted reproduction cycles

BACKGROUND

The aspiration of the granulosa cells that surround the oocyte and the use of gonadotropin releasing hormone agonists (GnRHa) during assisted reproduction technology (ART) treatment can interfere with the production, during the luteal phase, of progesterone, which is necessary for successful implantation of the embryo. Providing hormonal supplementation during the luteal phase with either progesterone itself, or human chorionic gonadotropin (hCG), which stimulates progesterone production, may improve implantation and, thus, pregnancy rates.

OBJECTIVES

To determine (1) if luteal phase support after assisted reproduction increases the pregnancy rate, (2) the optimal hormone for luteal phase support, i.e. hCG, progesterone, or a combination of both, and (3) the optimal route of progesterone administration.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group trials register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1971 to Dec 2003), EMBASE (1985 to Dec 2003). We handsearched reference lists of relevant articles were scanned, and abstract books from scientific meetings up to December 2003.

SELECTION CRITERIA

Randomized controlled trials of luteal phase support after ART treatment, comparing hCG or progesterone with placebo or no treatment, comparing progesterone with hCG, progesterone plus hCG, or progesterone plus estrogen, or comparing different routes of progesterone administration. Quasi-randomized trials were excluded from the main analyses, but included in a secondary analysis for each comparison.

DATA COLLECTION AND ANALYSIS

For each comparison, data on live birth, ongoing and clinical pregnancy per embryo or gamete transfer procedure, miscarriage per clinical pregnancy, ovarian hyperstimulation syndrome (OHSS) per transfer, and multiple pregnancy per clinical pregnancy were extracted into 2 x 2 tables and subgrouped by use of GnRHa in the ovarian stimulation regimen. The odds ratio (OR) and risk difference (RD) were calculated.

MAIN RESULTS

Fifty-nine studies were included in the review. Luteal phase support with hCG provided significant benefit, compared to placebo or no treatment, in terms of increased ongoing pregnancy rates (odds ratio (OR) 2.38, 95% confidence interval (CI) 1.32 to 4.29) and decreased miscarriage rates (OR 0.12, 95% CI 0.03 to 0.50), but only when GnRHa was used. The odds of OHSS increased 20-fold when hCG was used in cycles with GnRHa. Progesterone use resulted in a small but significant increase in pregnancy rates (OR 1.34, 95% CI 1.01 to 1.79) when trials with and without GnRHa were grouped together, but no effect on the miscarriage rate was observed. No significant difference was found between progesterone and hCG or between progesterone and progesterone plus hCG or estrogen in terms of pregnancy or miscarriage rates, but the odds of OHSS were more than 2-fold higher with treatments involving hCG than with progesterone alone(OR 3.06, 95% CI 1.59 to 5.86). Comparing routes of progesterone administration, reductions in clinical pregnancy rate with the oral route, compared to the intramuscular or vaginal routes, did not reach statistical significance, but there was evidence of benefit of the intramuscular over the vaginal route for the outcomes of ongoing pregnancy and live birth. No significant difference in pregnancy rate was observed between vaginal progesterone gel and other types of vaginal progesterone.

REVIEWERS' CONCLUSIONS

Luteal phase support with hCG or progesterone after assisted reproduction results in an increased pregnancy rate. hCG does not provide better results than progesterone, and is associated with a greater risk of OHSS when used with GnRHa. The optimal route of progesterone administration has not yet been established.

Comparison of the efficacy and safety of two formulations of micronized progesterone (Ellios and Utrogestan) used as luteal phase support after in vitro fertilization

OBJECTIVE

To compare the efficacy and the tolerability of two different vaginal formulations of micronized progesterone, Ellios and Utrogestan, used for luteal phase support after an in vitro fertilization (IVF) cycle.

DESIGN

Cohort study.

SETTING

Fertility center in a university hospital. PATIENT(S(: One hundred twenty-three women who underwent IVF/intracytoplasmic sperm injection (ICSI) stimulated cycles from October 1998 to March 2000, who had at least six follicles of > or =14 mm on the day of hCG administration.

INTERVENTION(S)

Patients received Ellios pessaries (2 times 200-mg pessary/day) or Utrogestan capsules (2 x 100-mg capsules, two times a day). Progesterone was administered from the day of oocyte pickup (day 0) until menses or up to 10 weeks in pregnant patients.

MAIN OUTCOME MEASURE(S)

Progesterone levels, pregnancy rate, and tolerability tested by patient questionnaire.

RESULT(S)

The progesterone levels on days 0, 9, 16 were not statistically different between the two formulations. The pregnancy rate were similar in groups 1 and 2 (25.5% vs. 18.6%), whereas tolerance was significantly better in group 1 versus group 2 (vaginal discharge: 43% vs. 82%).

CONCLUSION(S)

The efficacy of the two formulations of progesterone is comparable, although the patient tolerance for Ellios is better.

Progesterone supplementation during early gestation after in vitro fertilization has no effect on the delivery rate

OBJECTIVE

To compare the delivery rate with IVF or ICSI in women who did and did not receive progesterone supplementation in the first 3 weeks after a positive hCG test result.

DESIGN

Retrospective study.

SETTING

Fertility Clinic, Rigshospitalet University Hospital, Copenhagen, Denmark.

PATIENT(S)

200 pregnant women who did not receive progesterone (intervention group) and 200 pregnant women who received progesterone for 3 weeks after a positive hCG result.

INTERVENTION(S)

In the study group, vaginal progesterone therapy was withdrawn on the day of positive hCG result. In the control group, treatment with progesterone, 600 mg/d, was continued for 3 weeks after a positive hCG result. Both groups received 600 mg of progesterone starting on the day of embryo replacement until testing positive for pregnancy 14 days after embryo transfer.

MAIN OUTCOME MEASURES

Delivery rate.

RESULT(S)

The number of deliveries was 126 in the study group and 128 in the control group.

CONCLUSION(S)

The delivery rate was the same in pregnant women who received and those who did not receive progesterone for 3 weeks after a positive hCG result. Progesterone supplementation for more than 2 weeks after embryo transfer may therefore yield no benefit in terms of pregnancy.

Selective early elimination of luteal support in assisted reproduction cycles using a gonadotropin-releasing hormone agonist during ovarian stimulation

OBJECTIVE

To determine if women undergoing GnRH agonist-hMG stimulated IVF cycles can undergo successful discontinuation of luteal phase support.

DESIGN

A protocol for selective discontinuation of luteal phase support was evaluated prospectively in women undergoing assisted reproduction cycles.

SETTING

A tertiary care institutional-based assisted reproduction program.

PATIENT(S)

One hundred eighty-eight women who conceived after an IVF or zygote intrafallopian transfer cycle including a GnRH agonist between January 1994 and June 1997.

INTERVENTION(S)

Women with serum progesterone levels of > or = 60 ng/mL at 4 weeks' gestation were selected for discontinuation of their luteal phase support.

MAIN OUTCOME MEASURE(S)

Delivery rate.

RESULT(S)

Sixty-three women (62.4%) met the criteria for discontinuation of luteal phase support. There were no differences in the mean age, peak E2 levels, number of follicles, number of embryos transferred, or delivery rates (85.7% versus 78.9%) between the women who did and those who did not have discontinuation of their progesterone supplementation.

CONCLUSION(S)

These data reveal that luteal phase support can be discontinued successfully for selective women undergoing IVF who are receiving a GnRH agonist.

Ovarian follicular wave synchronization and superstimulation in prepubertal calves

Two experiments were designed to artificially alter the follicular wave pattern in calves to determine if the mechanisms controlling the well-ordered pattern of follicular growth in adults are extant in prepubertal animals as well. Experiment 1 was designed to test the hypothesis that follicle ablation in a random group of calves will induce synchronous emergence of a new follicular wave which is not different from a spontaneous wave. Experiment 2 was designed to test the hypothesis that ovarian superstimulatory response in calves is enhanced when treatment is initiated before rather than after the time of selection of the dominant follicle. In Experiment 1, 6-month-old calves were assigned randomly to an ablation group (n = 10) and a control group (no ablation, n = 10). Follicle ablation was accomplished by transvaginal ultrasound-guided needle aspiration of all follicles > or = 4 mm in diameter. Blood samples were taken and ovarian changes were monitored daily. A rise (P < 0.01) in mean plasma FSH concentration was detected 24 h after follicle ablation (1.51 ng/ml in the ablation group and 0.93 ng/ml in the control group). Wave emergence was detected earlier (P < 0.01) and with less variation (P < 0.0001) in the ablation group than the control group (1.2 +/- 0.1 vs 4.0 +/- 0.7 d). Characteristics of the induced wave were not different from those of the spontaneous wave. In Experiment 2, 7-month-old calves were assigned randomly to a pre-selection group in which superstimulation treatment was initiated at the time of wave emergence (1 d after follicle ablation, n = 11), or to a post-selection group in which superstimulation treatment was initiated after selection of a dominant follicle (4 d after follicle ablation, n = 11). Superstimulation treatment consisted of 30 mg of FSH im twice daily for 3 d. Ultrasound-guided transvaginal follicle ablation was used to synchronize follicle wave emergence at the outset of the experiment. The mean diameter of the largest follicle at the start of superstimulation treatment was 3.2 versus 8.5 mm in the pre- and post-selection groups, respectively (P < 0.001). The day after the last treatment, the number of follicles > or = 3 mm in diameter was greater (P < 0.002) in the pre-selection group than in the post-selection group (19.3 +/- 1.7 versus 11.3 +/- 1.3). In summary, ultrasound-guided follicle ablation resulted in synchronous wave emergence in a random group of calves, and superstimulation treatment initiated at the time of wave emergence (pre-selection group) resulted in the growth of more follicles than treatment initiated later (post-selection group). Mechanisms involved in the control of follicle recruitment, selection, and suppression are extant in calves, similar to those found in adults.

Gamete intrafallopian transfer

GIFT involves placement of a donor's oocyte into a surrogate's oviduct. Fertilization and embryo development occur within the recipient's reproductive tract. GIFT provides a viable method to obtain pregnancies from subfertile mares for which embryo transfer has been nonproductive. Currently, pregnancy rates after GIFT have been variable, although high success rates have been reported recently. Further refinement of techniques should allow GIFT to be used in research and commercial programs.

Is there a role for estrogen in follicular maturation in the primate?

The present study focusses attention on the effects of blocking estrogen synthesis, during follicular phase, on follicular maturation in the adult female bonnet monkey (Macaca radiata). Administration of cycling females (n=4) with an aromatase inhibitor CGS 16949A (Al) by Alzet mini-pump (2,5 mg/day) from day 3 of cycle resulted in significant reduction in basal (by 53%) and surge levels of estrogen (by 70%) but this had no effect on follicular maturation, ovulation and luteal function as assessed by serum hormone profiles as well as laparotomy. This lack of need for estrogen for completion of follicular maturation process was confirmed by administering cycling monkeys hFSH (25 IU/day) from day 3 till day 8 of the cycle along with (5 mg Al/day) or without Al (n=3/group). Administration of AI resulted in suppression of FSH induced increase in serum estrogen (by 100%) and elevation in circulating androstenedione. Aromatase inhibitor treatment had no effect on either the number of follicles developed or their size relative to control. Testing the ability of both granulosa and thecal cells, removed on day 9 of treatment cycle, to respond to gonadotropinsin vitro showed no change indicating that cellular development and maturation of follicular cells had occurred normally. It is concluded that follicular maturation in the primate can occur even when increase in estrogen synthesis is blocked.

Ovarian synchronization following ultrasound-guided transvaginal follicle ablation in heifers

In Experiments 1 and 2, ultrasound-guided transvaginal follicle aspiration was used as a method of follicle ablation to induce and synchronize subsequent follicular wave emergence and enhance ovulation synchrony following PGF2alpha administration. Heifers were at unknown stages of the estrous cycle at the start of both experiments in which all follicles>or=5 mm in diameter were ablated; luteolysis was induced 4 d later with cloprostenol (500 ug/dose, im). In Experiment 1, heifers were randomly assigned to either an ablation (n=17) or a procedural control (no follicle ablation, n=17) group. Ablation-induced wave emergence was indicated by a significant increase in the total number of follicles>or=5 mm within 2 d of ablation (mean, 1.5 d), which was preceded by a significant surge in circulating FSH. Although the mean (+/-SEM) interval from PGF2alpha administration to ovulation did not differ between follicle-ablated heifers (5.1+/-0.5 d range, 3 to 9 d) and control heifers (5.1+/-1.0 d; range, 1 to 5 d), the variability of the interval was different (P<0.05). Inequality of variance between the 2 groups was attributed to a greater (P<0.08) degree of ovulation synchrony in the ablation group than in the control group; 13/16 (81%) versus 9/17 (53%), respectively, ovulated within 5 d of cloprostenol administration. Relative asynchrony of ovulations in control heifers was associated with the status of the follicular wave at the time of PGF2alpha administration and, in part, to incomplete luteolysis following a single dose of PGF2alpha. Experiment 2 was designed to examine the efficacy of 2 doses of cloprostenol 12 h apart (n=7) versus a single dose (n=8) to induce complete luteolysis subsequent to follicle ablation-induced wave emergence. Two doses of cloprostenol potentiated ovulation synchrony; more (P<0.05) 2-dose heifers (7/7, 100%) than single-dose heifers (4/8, 50%) ovulated within 5 d after PGF2alpha administration. In summary, ultrasound-guided transvaginal follicle ablation, done at random during the estrous cycle, induced and synchronized subsequent follicular wave emergence, and resulted in a high degree of ovulation synchrony among heifers after PGF2alpha induced luteolysis, especially when 2 doses of PGF2alpha were administered 12 h apart.

The luteal phase after oocyte recovery in a spontaneous cycle

There is disagreement as to whether follicular aspiration and oocyte recovery leads to a defective luteal phase. A group of 20 women with mild endometriosis was studied over two consecutive spontaneous cycles. Follicular aspiration and oocyte recovery was performed 32 hours after the onset of the endogenous luteinizing hormone surge during the second cycle. There was little disturbance of the luteal phase or in the pituitary gonadal relationship in the aspirated cycle. Although a significantly lower serum progesterone was noted on day 8 of post-oocyte recovery, all results were within the normal range seen in the control cycles.

Pregnancy rate and ovarian hyperstimulation after luteal human chorionic gonadotropin in in vitro fertilization stimulated with gonadotropin-releasing hormone analog and menotropins

The value of luteal phase supplementation with human chorionic gonadotropin (hCG) was assessed after a combined protocol of ovarian stimulation, using a long acting gonadotropin releasing hormone analog (GnRH-a) and human menopausal gonadotropins (hMG), in a randomized prospective study of 36 consecutive cycles in an in vitro fertilization (IVF) program. The patients were allocated on the transfer day to either luteal phase supplementation with hCG (Group A, n = 18) or none (Group B, n = 18). Nine patients of Group A conceived as compared with 3 in Group B. Five patients, all in Group A, developed ovarian hyperstimulation syndrome (OHSS) (3 moderate and 2 severe forms). Analysis of the hormonal profiles disclosed similar progesterone (P), estradiol (E2), and E2/P ratio up to the 6th post ovum pick-up day. Then, E2 and mainly P levels decreased only in Group B resulting in a rising E2/P ratio. These findings stress the importance of luteal support in IVF cycles treated with GnRH-a. In light of the increased risk of OHSS among hCG treated patients, further studies are needed to assess the optimal preparation needed.

In vitro fertilization: the degree of endometrial insufficiency varies with the type of ovarian stimulation

Fifty-eight patients in an in vitro fertilization program who did not have embryo transfers had endometrial biopsies performed on the second day after ovulation. The patients had been stimulated with clomiphene citrate (CC) and human chorionic gonadotropin (hCG) (group I); with CC, human menopausal gonadotropin (hMG), and hCG (group II), or with hMG and hCG (group III). Only 17 patients (30%) showed a normal luteal phase histology. The remaining 41 patients (70%) showed variety of endometrial abnormalities. Patients stimulated with hMG and hCG (group III) had a normal luteal phase at a significantly higher rate (48% versus 16%). Women below the age of 35 had a significantly higher rate of normal luteal phase histology than women older than 35 years. The study establishes abnormal endometrial histology as a possible cause of the low pregnancy rate of in vitro fertilization. The degree of endometrial histologic abnormality varies considerably with the type of ovarian stimulation used.

A short luteal phase in cycles stimulated with clomiphene and human menopausal gonadotropin for in vitro fertilization

Of 70 cycles stimulated with clomiphene and human menopausal gonadotropin (hMG) for an in vitro fertilization-embryo transfer (IVF-ET) program, a short luteal phase of 11 days or less was found in 18. In this group the mean estradiol and progesterone levels were elevated in the early luteal phase. Despite the elevated initial values, progesterone levels fell rapidly at the mid luteal phase as a sign of premature luteolysis. The mean total amount of gonadotropin administered and the mean number of follicles punctured and of oocytes recovered did not show any significant difference between the groups of normal and short luteal phases. The present findings support the theory that hyperestrogenism in the early luteal phase may initiate the premature luteolysis observed in clomiphene-menopausal gonadotropin-stimulated cycles.

Contributions of in vitro fertilization to knowledge of the reproductive endocrinology of the menstrual cycle

The administration of ovarian stimulants to endocrine-normal women in IVF programmes gives the clinical endocrinologist an opportunity to modify natural folliculogenesis. Use of antioestrogens and/or gonadotrophins at the correct time has demonstrated that follicular atresia can be prevented and that multiple pregnancy-potent haploid ova can be obtained. Scrutiny of spontaneous menstrual cycles in patients who show unsatisfactory IVF responses has identified two new syndromes, premature follicle selection and occult ovarian failure, in these patients. The incidence of these disorders in fertile women is still unclear. Early results suggest that endocrine manipulations may overcome premature follicle selection and induce codominant folliculogenesis. Inhibin is a recently characterized ovarian protein which is increased in peripheral blood during IVF treatment. Results from IVF cycles suggest that plasma inhibin may be a new index of follicular function. Other potential indices of ovarian function, such as the luteal protein relaxin, may also develop from the application of basic research to IVF and advance knowledge of the human ovarian and menstrual cycles.

Use of primate folliculogenesis models in understanding human reproductive biology and applicability to toxicology

The nonhuman primate reproductive system provides an excellent model for studying basic physiological processes applicable to humans. This article reviews hormonal observations and experimental manipulations useful in the evaluation of ovarian events in various stages of the reproductive life. As the need arises, primate reproductive toxicological studies may clarify questions relevant to human risk evaluations. Evaluation of reproductive toxicological observations may reveal biological parameters defining premature reproductive failure.

Serum progesterone levels in women treated with human menopausal gonadotropin and human chorionic gonadotropin for in vitro fertilization

For evaluation of the adequacy of luteal function after in vitro fertilization-embryo transfer (IVF-ET), serum progesterone (P) levels were measured on days 3, 7, and 10 after laparoscopic follicle aspiration. Fifty-six infertile patients were treated during 86 cycles with human menopausal gonadotropin-human chorionic gonadotropin (hMG-hCG) for stimulation of follicular development. Serum estradiol (E2) levels were measured daily during hMG-hCG treatment. P levels were determined in 67 cycles. The mean (+/- standard deviation [SD]) of the sums of 3 P levels was 55.63 +/- 24.13 ng/ml. There were 11 pregnancies. The mean of the sums of 3 P levels of pregnant patients was 64.45 +/- 26.23 ng/ml and of 56 nonpregnant cycles was 53.90 +/- 23.35 ng/ml. The duration of luteal phase varied from 9 days to 15 days. The mean of the sums of 3 P values of patients with different luteal phase lengths ranged from 28.8 ng/ml to 60.51 +/- 25.68 ng/ml. The mean of the sums of 3 P levels of women with normal luteal phase and that of women with luteal phase defect by endometrial biopsy study were used as controls for comparison. There was poor correlation (r = 0.3441) between E2 peak levels and P levels; the sum of 3 P levels did not indicate luteal phase inadequacy in IVF-ET patients; and the majority of the nonpregnant cycles (32/56) showed a luteal phase of 11 days or less, in spite of adequate P levels.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of progesterone supplementation around the time of oocyte recovery in patients superovulated for in vitro fertilization

A randomized control trial involving 42 superovulated in vitro fertilization (IVF) patients was carried out to investigate the effects of providing supplementary progesterone (P) around the time of laparoscopy. P was given 12 to 15 hours and 1 hour before and 24 hours after laparoscopy in one group (group B); human chorionic gonadotropin was given 12 hours before laparoscopy in another group (group C); and the remainder received no treatment in addition to normal IVF procedures (group A). There was no difference in fertilization rate, the proportion of normally developing embryos, pregnancy rate, or birth rate between the treatment groups, We conclude that in the superovulation schedule used, P supplementation around the time of laparoscopy does not affect success rate of IVF.

The effect of laparoscopic follicular aspiration on ovarian steroidogenesis during the early preimplantation period

Seventeen patients were studied for the first 72 hours of the luteal phase after spontaneous ovulation or follicle aspiration. Nine patients (group I) underwent follicle aspiration after clomiphene citrate (CC) administration, three women were studied after CC for ovulation induction (group II), and five spontaneous ovulating subjects served as controls (group III). Serum progesterone (P) concentrations were significantly elevated in stimulated cycles with or without follicle aspiration, compared with subjects. Moreover, when aspirated subjects were compared with nonaspirated stimulated subjects, a significant difference in P concentration was identified. It can be concluded that with follicle aspiration, P decreases can be observed, but with multiple follicle development, inadequate P levels are not seen in these stimulated subjects. On the contrary, with such elevated P levels, endometrial advancement may play a role in poor implantation success with human in vitro fertilization procedures.

Follicular development: lessons learned from human in vitro fertilization

In vitro fertilization has offered new insights into our understanding of ovulation induction, folliculogenesis, and luteal phase events. This new information is provided by the ability to precisely study these cycles in a frequent and sequential fashion through the use of peripheral blood markers, ultrasound evaluation, and follicular fluid constituents and cell culture techniques, as well as direct observation of the oocyte, fertilization, and cleavage. In these stimulated cycles the follicular phase serum estradiol levels in conjunction with ultrasound were evaluated; a poor correlation was shown between follicle size and number and estrogen production. This distinct dyssynchrony suggests the recruitment of a number of cohorts of follicles in each stimulated cycle. From the biochemical markers in follicular fluid, cyclic adenosine monophosphate has a distinct predictive value in regard to pregnancy in in vitro fertilization-embryo transfer cycles. In the luteal phase, the mass effect of aspiration of great numbers of granulosa cells, the effect of supplemental progesterone, and the influence of high follicular phase estradiol levels remain controversial and, therefore, a less clear cut pattern emerges. Variations in the protocol have not greatly improved the major problems of folliculogenesis associated with ovulation induction and an in vitro fertilization-embryo transfer program, that is, follicular asynchrony and luteal phase deficiency.

The luteal phase after hyperstimulation for in vitro fertilization

Of 500 cycles in which in vitro fertilization (IVF) was undertaken, laparoscopy was performed 372 times, 272 embryo transfers were carried out, and 55 pregnancies resulted, 30 of which resulted in delivery. Of those patients who underwent laparoscopy, 156 received clomiphene citrate alone, 203 clomiphene citrate and hMG, and 13 hMG alone. All patients were found to have a luteal-phase length of 10 days or greater (measured from the time of ovulation). The midluteal urinary total estrogen (UTE) value and pregnanediol excretion (Pd2) far exceeded the levels seen in normal cycles. There were no significant differences between conceptual and nonconceptual cycles and the high levels encountered would be expected after deliberate hyperstimulation. Fifty-five patients (in whom 11 pregnancies resulted) were monitored every other day throughout the luteal phase after embryo transfer. Both conceptual and nonceptual cycles showed a peak in pregnanediol glucuronide level around luteal day 6, which then fell. The level rose again if the corpus luteum was "rescued" by the implanting embryo. While the difference was not statistically significant, the estradiol levels appeared to decrease earlier in the nonconceptual cycles than in the continuing pregnancy cycles. It is important to note that the pattern of steroid production in the follicular phase was similar in both conceptual and nonconceptual cycles. While these data are not conclusive, they suggest that some nonconceptual cycles may have suffered early corpus luteal regression. Whether luteal-phase support is indicated in patients treated with clomiphene or clomiphene/hMG therapy cannot be determined from this study. However, it is thought that a controlled study of luteal-phase support in patients so stimulated is warranted. It appears that patients treated with hMG alone tend to undergo a compressed cycle and should be given luteal-phase support since other studies have reported shortened luteal phases following such hMG therapy.

Sequential use of clomiphene citrate, human menopausal gonadotropin, and human chorionic gonadotropin in human in vitro fertilization. II. Study of luteal phase adequacy following aspiration of the preovulatory follicles

The 88 patients included in the in vitro fertilization program during 113 cycles were submitted to superovulation by sequential use of clomiphene citrate, human menopausal gonadotropin, and human chorionic gonadotropin. No correlation was found between estradiol and progesterone levels during the luteal phase and estradiol on the days preceding administration of human chorionic gonadotropin. Nineteen biopsies of the endometrium were carried out. The importance of the increase of estradiol between the day before and the day of administration of human chorionic gonadotropin is positively correlated with the quality of the endometrium.

Influence of laparoscopic follicular aspiration under general anaesthesia on corpus luteum progesterone secretion in normal and clomiphene-stimulated cycles

In 32 patients with unstimulated normal cycles and 24 with cycles stimulated with clomiphene and human chorionic gonadotrophin (hCG) all visible follicles were punctured laparoscopically under general anaesthesia for the purpose of in vitro fertilization. In unstimulated cycles the time of surgery was between 24 and 32 h after the first luteinizing hormone (LH) increase in the urine; in the cycles stimulated with hCG (5000 i.u.) laparoscopy was between 35 and 37 h after injection. Blood samples for progesterone determination were taken about 7 days later. Progesterone levels were compared with those in a control group not subjected to surgery, in which the progesterone levels were determined 7 days after the LH increase. There was no statistically significant difference in the progesterone levels in the unstimulated subjects after laparoscopy compared with those in the control subjects but progesterone levels in the stimulated subjects were significantly higher (p less than 0.01). Durations of the luteal phases showed no significant differences thus laparoscopy under general anaesthesia does not impair luteal function.

Hormonal and histological study of the luteal phase in women following aspiration of the preovulatory follicle

A hormonal and histologic study of 60 luteal phases was carried out in 40 patients during spontaneous and stimulated cycles before and after follicle puncture for oocyte recovery. The duration of the luteal phase was modified neither by follicle rupture nor by hormonal stimulation. The aspiration of a spontaneous preovulatory follicle caused a temporary deficiency in plasma progesterone (P) (P less than 0.01) on the third day following aspiration, and a higher prolactin (PRL) level (P less than 0.02) on the ninth day. Dystrophia of the endometrium was observed in one-third of the cases, whereas the P level was normal. In cycles stimulated by clomiphene citrate, no P deficiency was observed. When luteinizing hormone (LH) discharge occurred spontaneously, biopsies carried out 3 days following follicle aspiration indicated a normal secretory state of the endometrium, and the P level was higher from, the sixth day following aspiration (P less than 0.05), as compared with the control cycles. This phenomenon was not observed when human chorionic gonadotropin (hCG) was administered.