The cumulative embryo score: a predictive embryo scoring technique to select the optimal number of embryos to transfer in an in-vitro fertilization and embryo transfer programme

[Towards a single embryo transfer: predictive value of uterine and embryological parameters in assisted reproduction outcome]

OBJECTIVE

The transfer of a single embryo would avoid obstetrical and neonatal complications due to multiple pregnancies. We studied the clinical value of both uterine and embryological parameters to define precise conditions allowing a single embryo transfer without decreasing pregnancy rates.

PATIENTS AND METHODS

Endometrial parameters expressed by a uterine score together with biological criteria of 131 in vitro fertilization or intracytoplasmic sperm injection attempts were retrospectively analysed.

RESULTS

Two hundred and sixty-two day-3 embryos were replaced through 131 transfers. Fifty-seven pregnancies were induced and 16 twins were obtained. The clinical pregnancy rate was 35.9% and the embryonic implantation rate 24.0%. After the transfer of two embryos, successful implantation was determined by the occurrence of top-quality embryos and simultaneously by a receptive endometrium. The uterine pulsatility index was significantly decreased for twin compared to singleton pregnancies.

DISCUSSION AND CONCLUSION

This study confirms that a uterine score constitutes a powerful tool for evaluating the uterine receptivity. This parameter has to be taken into account as well as the embryonic quality, in order to optimise the success rate. Young patients with at least two top-quality embryos available, a high uterine score and a low pulsatility index, have a high risk of multiple births and are suitable for a single-embryo transfer.

Transfer of nonselected transferable day 3 embryos in low embryo producers

OBJECTIVE

To examine the implantation potential of embryos from assisted reproductive technology cycles with low embryo production and to assess the effects of clinical variables and embryo scores (ES) on pregnancy outcome.

DESIGN

Prospective clinical study.

SETTING

Assisted reproductive technology unit in a tertiary medical center.

PATIENT(S)

From July 1998 to December 2001, 280 cycles in 229 infertile couples produced a limited number of one, two, or three embryos 3 days after oocyte retrieval and underwent fresh embryo transfer (ET).

INTERVENTION(S)

Embryos with two or more blastomeres were scored and transferred.

MAIN OUTCOME MEASURE(S)

ES and implantation rate per ET.

RESULT(S)

Of 863 fresh ET cycles during the study period, 32.4% (280) were low embryo producers. Among them, there were no significant differences in average ES of individual embryos in single, dual, or triple ET or in embryos obtained from patients with low or high E2 responses, or young or old age. Embryos derived from conventional IVF had a better ES than those derived from intracytoplasmic sperm injection. The clinical pregnancy rate was strongly correlated with the cumulative ES. Implantation rates were similar among and between groups, with an average rate of 15.9%.

CONCLUSION(S)

Embryos of low embryo producers had an inherently low implantation potential that appeared to be unrelated to the number of embryos transferred, female age, ovarian E2 genesis, or fertilization method. The cumulative ES can serve as a predictor of pregnancy.

Comparison of the response to ovarian stimulation between women with one ovary and those with two ovaries, in a program of ICSI/ET

BACKGROUND

Women with a single ovary form a group of special interest in assisted reproduction. The aim of this study was to compare the outcome of intracytoplasmic sperm injection cycles between women with one and two ovaries. To our knowledge, this is the first study reporting the outcome of intracytoplasmic sperm injection cycles with women with a single ovary.

METHODS

Sixty-three intracytoplasmic sperm injection cycles in 24 women with a single ovary were compared with 191 intracytoplasmic sperm injection cycles in 109 women with both ovaries. All cycles were stimulated with triptorelin-long protocol.

RESULTS

Statistically significant differences were found in the following parameters between women with a single ovary and women with two ovaries: total number of administrated gonadotropins (63.22 +/- 45.03 vs. 44.72 +/- 21.92), number of follicles (8.29 +/- 5.02 vs. 14.45 +/- 7.94), estradiol peak levels (1695.05 +/- 1177.34 vs. 2728.51 +/- 1852.67), number of retrieved metaphase II oocytes (6.95 +/- 3.78 vs. 11.72 +/- 6.11) and number of 2 PN oocytes (4.07 +/- 2.85 vs. 6.53 +/- 4.14). There were no differences in duration of stimulation, number of transferred embryos, and cumulative embryo score. In the group of women with a single ovary 14 pregnancies were achieved (22.2%), whereas 33 pregnancies were achieved in the group of women with two ovaries (17.28%).

CONCLUSIONS

Women with a single ovary have a decreased response to external ovarian stimulation than women with both ovaries, but they present a higher, although not statistically significant, pregnancy rate.

The effect of preincubation period of oocytes on nuclear maturity, fertilization rate, embryo quality, and pregnancy outcome in IVF and ICSI

PURPOSE

To clarify the effect of preincubation of oocytes on the results of IVF and ICSI.

METHODS

A total of 176 IVF and 64 ICSI cycles received long protocol ovarian stimulation. The oocytes were incubated for 1-8 h before insemination or sperm injection. Metaphase II (MII) percentage was evaluated in the ICSI arm; fertilization rates, embryo quality, and pregnancy outcomes were analyzed in both IVF and ICSI arms according to the preincubation period duration of oocytes.

RESULTS

The MII percentage of the ICSI arm was significantly lower (P < 0.05) in the group with preincubation period of < 2.5 h. The fertilization rates in groups with preincubation for 2.5-5.5 h were significantly higher (P < 0.001) for IVF. Embryo quality and pregnancy outcomes were not significantly different between the IVF or ICSI arm.

CONCLUSIONS

The preincubation of oocytes for at least 2.5 h is beneficial to both IVF and ICSI outcomes by increasing the nuclear maturity of oocytes.

Effect of blastomere loss on the outcome of frozen embryo replacement cycles

OBJECTIVE

To assess the impact of survival of cryopreservation and thawing with all blastomeres intact on the outcome of frozen embryo replacement (FER) cycles.

DESIGN

Prospective observational study.

SETTING

University-affiliated tertiary referral assisted conception unit.

PATIENT(S)

The number of intact blastomeres before cryopreservation and after thawing was prospectively recorded in 1,687 cleavage-stage embryos thawed in 377 FER cycles. The cycles were categorized into two groups: group A (n = 184) included cycles in which all embryos transferred survived the cryopreservation and thawing process with all their original blastomeres intact; group B (n = 193) included cycles in which embryos transferred included at least one partially damaged embryo that has lost up to 50% of its original blastomere number.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Pregnancy and embryo implantation rates.

RESULT(S)

Groups A and B were comparable with respect to mean age at cryopreservation, mean number of oocytes retrieved and fertilized normally in the fresh cycle, and mean age at frozen transfer. No significant difference was found between the two groups with regard to mean number of frozen and thawed embryos per cycle and mean endometrial thickness reached before P supplementation. More embryos were transferred per cycle in group B than group A (2.4 +/- 0.6 vs. 2.1 +/- 0.6, respectively). However, the pregnancy and clinical pregnancy rates per cycle were significantly higher in group A than in group B (39.1% and 28.3% vs. 22.8% and 13.5%, respectively). The implantation rate was also higher in group A than in group B (17.3% vs. 8.1%, respectively).

CONCLUSION(S)

FER cycles in which all embryos transferred remained fully intact at thawing achieve a better outcome than those with at least one partially damaged embryo.

Day 3 and day 5 morphological predictors of embryo viability

Controlling multiple pregnancies in patients undergoing artificial reproductive procedures requires consideration of single embryo transfers. Therefore, refinements for embryo evaluation are needed that select for the most developmentally competent embryo. The present study was designed to identify day 3 and day 5 morphological predictors of viability following transfers in which the morphology and fate of each embryo was precisely determined. Assessments on day 3 included cell number, and the extent of fragmentation and asymmetry, and on day 5, the developmental stage. Embryos resulting in a viable fetus at 11 weeks gestation were considered developmentally competent. The relationships among individual and collective embryo morphological characteristics were evaluated. Analysis of the interactions among morphological characteristics of embryos transferred on day 3 enabled identification of a multivariable selection order. Assessment of day 5 embryos revealed that expanding and expanded blastocysts exhibited comparable developmental potential that was superior to that of either morulae or early blastocysts. However, expanding or expanded blastocysts derived from 7-cell or 8-cell embryos were developmentally superior to those derived from other cleavage stages, regardless of fragmentation or asymmetry. Collectively, these findings further understanding of morphological predictors of viability, thereby improving the ability to select the most viable embryo for transfer.

Pronuclear scoring as a predictor of embryo development

Many strategies have been proposed for the selection of viable embryos for transfer in human assisted reproduction. These have included morphological scoring criteria for day 1, 2, 3 and 5 embryos or combinations of these. Other strategies have used predictors such as timing of certain key events, as with early cleavage to the 2-cell, development to the 8-cell stage or patterns of fragmentation. All have shown some correlations with implantation. However, the overall success of these methods is still limited, with over 50% of all transferred embryos failing to implant. The use of pronuclear oocyte morphology has shown correlations with implantation and development to the blastocyst stage. The key aspects of pronuclear scoring, namely the presence of a cytoplasmic halo, the orientation of the nuclei in relation to the polar bodies and the size, number and pattern of distribution of nucleolar precursor bodies (NPB) in the nuclei were related to day 2,3 and 5 development, rate of development and day 3 and 5 morphology in a retrospective study. The pattern of the NPB or Z-score and the presence/absence of a halo had a significant effect on the rate of development on day 3 and day 5 and on the overall embryo morphology score. Low Z-score resulted in slow development, poor blastocyst formation and low morphology scores. The absence of a halo also resulted in slow and poor development, poor morphology, increased fragmentation and increased numbers of poor Z-scored embryos. The use of PN scoring can help predict embryos that have poor developmental potential, aid in early selection and may indicate the health of the oocyte.

Effects of cryopreservation on testicular sperm nuclear DNA fragmentation and its relationship with assisted conception outcome following ICSI with testicular spermatozoa

The objective of the study was to investigate the effects of freeze-thawing on testicular sperm DNA fragmentation, fertilization rates and pregnancy rates following intracytoplasmic sperm injection with testicular spermatozoa (TESE). This ongoing prospective study included 88 couples attending for infertility treatment where the man presented with obstructive azoospermia at the Regional Fertility Centre, Belfast, UK. Patients were allocated to receive TESE treatment with fresh or freeze-thawed spermatozoa. Sperm aliquots were stored in liquid nitrogen at -196 degrees C following static phase vapour cooling or cooling at controlled rates using a programmable freezer. Samples were thawed at either room temperature or 37 degrees C. Sperm nuclear DNA; assessed by the alkaline Comet assay, was significantly damaged by slow freezing followed by fast thawing. Pregnancies were more likely to be achieved with spermatozoa displaying markedly less DNA damage. However, no differences were observed in the fertilization rates, the number of blastomeres or the cumulative embryo score between TESE cycles using either fresh or frozen thawed testicular spermatozoa. The pregnancy rates tended to be higher following fresh TESE cycles (30%) compared with TESE cycles using frozen-thawed testicular spermatozoa (26%), although this difference did not reach statistical significance. It is concluded that cryopreservation of testicular spermatozoa may reduce pregnancy rates, although this will only be confirmed by a much larger multi-centre trial.

Pronuclear and morphological features as a cumulative score to select embryos in ICSI (intracytoplasmic sperm injection) cycles according to sperm origin

PURPOSE

To analyze best parameter to select embryos according to sperm origin in ICSI cycles.

METHODS

One hundred seventy-two ICSI cycles were divided among three different groups: A (ejaculated spermatozoa from nonmale factor infertility), B (ejaculated spermatozoa from oligospermia), and C (spermatozoa from azoospermia). Embryos were divided on Day 1 into two patterns: S0 (pronuclei (PN) aligned and close with normal arrangement of nucleoli) and S1 (when these characteristics were absent) and also on transfer day according to morphological features.

RESULTS

Relationships of PN patterns related to sperm origin were noted. More S0 embryos were detected with better sperm quality. Higher number of good quality embryos was obtained when male factor was absent. Ejaculated and epididymal spermatozoa provide better quality embryos than do testicular spermatozoa.

CONCLUSIONS

PN classification associated with transfer day morphology is valuable additional noninvasive criterion for elective embryo transfer, mainly in the cases with severe male factor.

Embryo culture as a diagnostic tool

Embryo culture can serve as a strong diagnostic tool, yielding useful information regarding the implantation potential of the human embryo. The information thus gained is useful for quality control of the embryology laboratory, success rates of the IVF/intracytoplasmic sperm injection (ICSI) programme, and counselling of the couple following failed cycles. Zygotes can be scored and zygote quality has been associated with further embryonic development and cleavage stage embryo quality. Early cleavage, cleavage rate, cleavage stage embryo grade and subsequent progression of these embryos to the blastocyst stage have all been shown to be individual and collective markers for the implantation-competent human embryo. This manuscript discusses embryonic markers of normality/quality throughout in-vitro culture starting with the zygote and ending with the blastocyst.

Counselling on cryopreservation of pronucleated oocytes

The German Embryo Protection Law permits only the cryopreservation of supernumerary pronuclear stage eggs. Data are needed to counsel patients about their individual benefits from this procedure. All fresh embryo transfer cycles performed from January 1994 until December 1998 in which supernumerary pronucleate eggs were cryopreserved (n = 557) were analysed retrospectively, together with data from all subsequent cycles involving transfers of frozen-thawed pronucleate eggs (n = 420) from January 1994 until June 2001. The additional cumulative pregnancy rate per fresh cycle was 11.5%. This rate depended on the number of embryos per transfer, i.e. 1.9, 8.2 and 13.0% respectively when one, two or three embryos were transferred (P < 0.05). A strong correlation was found between the numbers of cryopreserved pronucleate eggs and pregnancy rates, of 9.3, 10.5 and 17.1% when 1-3, 4-6, or at least 7 pronucleate eggs were available respectively. Additional benefit in terms of this rate from cryopreservation for a patient with and without a pregnancy in the fresh embryo transfer cycles was 5.3 and 12.7% respectively. It is concluded that higher pregnancy rates in cycles involving cryopreserved eggs for patients who did not become pregnant in fresh transfer cycles reveals the disadvantage of the German Embryo Protection Law, which does not allow embryo selection. Therefore, cryopreservation of pronucleate eggs with a higher developmental potential is possible. The total pregnancy rate could be raised from 28.0 to 35.5% per fresh transfer cycle.

Aspects of the molecular regulation of early mammalian development

Many regulatory systems operate in the early mammalian embryo. This brief overview surveys several systems and their integration including polarities and axes, left-right differentiation, timers in cells, tissues and in gene expression, and imprinting. Polarities are essential from the very earliest stages of oocyte formation, and maintain their significance until blastocyst stages and beyond. They determine cleavage axes and the distribution of maternal proteins in the oocyte, distinct distributions being identified at the animal pole especially. Left-right axes are no doubt expressed from the earliest embryonic stages, and perhaps even in determining slight differences in the axes of cleavage and of maternal protein distribution. Timers, equally fundamental, have been demonstrated to control many functions in oocytes and embryos. Many fundamental processes in early mammalian oocytes and embryos are closely timed. They are classified into circadian rhythms, hourglass timers, clocks regulating major aspects of development including transcription, longevity via telomere clocks and long-range systems. Imprinting and methylation, increasingly important in establishing stable phenotypes in early embryos, might develop abnormally under some circumstances including intracytoplasmic sperm injection and cloning. A general summary briefly describes some other aspects of regulation, especially chromosomal anomalies in human embryos.

Improvement in early human embryo development using new formulation sequential stage-specific culture media

OBJECTIVE

To determine whether altering selected components of sequential culture media can improve early development variables of human embryos.

DESIGN

Prospective, randomized, sibling oocyte split trial.

SETTING

Private ART center.

PATIENT(S)

Two hundred eight undergoing treatment with in vitro fertilization or microinjection.

INTERVENTION(S)

Oocytes from each patient were randomly allocated to fertilization and cleavage media of a control and a trial culture medium formulation.

MAIN OUTCOME MEASURE(S)

Rates of fertilization, cleavage, and uncontrolled division; average embryo morphology score; blastomeres per embryo; embryo score parameter (number of blastomeres x embryo morphology grade); and embryo utilization. The trial media resulted in a higher fertilization rate, higher cleavage rate, lower rate of uncontrolled division, higher number of blastomeres per embryo, higher average embryo morphology score, a higher embryo score parameter, and higher embryo utilization rate compared to the control media. All differences were statistically significant.

CONCLUSION(S)

Improved sequential stage-specific culture media can reduce the occurrence of severe human embryo fragmentation and improve developmental variables in early IVF- and ICSI-generated embryos.

Embryological strategies for overcoming recurrent assisted reproductive technology treatment failure

In every assisted reproductive technology (ART) programme there are patients who experience repeated failure. If all laboratory and stimulation parameters are controlled, it is assumed that the underlying cause of failure is physiological, and is attributable to either of the gametes or the embryo. Within the laboratory, few tools are available, other than careful observation and embryo selection, to aid in selecting the right embryo to overcome this failure. The morphology of the zygote, the state of the cleaving embryos on day 2 and day 3 of development, and the blastocyst can influence implantation rates. However, without functional gametes it is unlikely that success can be achieved. An early indicator of this functionality is the morphology of the zygote, which can be influenced by either the oocyte or the spermatozoon, and can be altered by either improving oocyte quality during stimulation or by using donor sperm if the failure to conceive is attributable to the male gamete. Subsequently, selecting embryos for transfer on the basis of the morphology of zygotes and embryos at day 3 or day 5 of development with the addition of fragmentation scoring and assisted hatching has been found to overcome many cases of repetitive failure to conceive after ART.

Fundamentals of human embryonic growth in vitro and the selection of high-quality embryos for transfer

Knowledge of the nature of embryo growth, and the handling and scoring of quality in human embryos are significant aspects for embryologists in IVF clinics. This review describes the formation, growth and maturation of human oocytes, many aspects of fertilization in vitro, embryonic transcription during preimplantation stages, and the formation of polarities, timing controls, role of mitochondria and functions of endocrine and paracrine systems. Modern concepts are fully discussed, together with their significance in the practice of IVF. This knowledge is essential for the correct clinical care of human embryos growing in vitro, especially in view of their uncharacteristic tendency to vary widely in implantation potential. Underlying causes of such variation have not been identified. Stringent tests must be enforced to ensure human embryos develop under optimal conditions, and are scored for quality using the most advanced techniques. Optimal methods of culture are described, including methods such as co-culture introduced to improve embryo quality but less important today. Detailed attention is given to quality as assessed from embryonic characteristics determined by timers, polarities, disturbed embryo growth and anomalous cell cycles. Methods for classification are described. Approaches to single embryo transfers are described, including the use of sequential media to produce high-quality blastocysts. These approaches, and others involved in surgical methods to remove fragments, transfer ooplasm or utilize newer approaches such as preimplantation diagnosis of chromosomal complements in embryos are covered. New outlooks in this field are summarized.

Influence of polarization effects in ooplasma and pronuclei on embryo quality and implantation in an IVF program

PURPOSE

The presence of a clear half-moon-like zone of cytoplasm in oocytes is called "halo effect." The prognostic value of this effect is not yet determined. Aligned nucleoli in pronuclei (PN) represent a further polarization phenomenon and a marker for implantation potential. Aim of the prospective study was to evaluate the influence of the halo effect on IVF outcome and to compare the results with observed polarization in PN.

METHODS

A total of 374 cycles with embryonic transfer were analyzed regarding halo effect and pattern of nucleoli. The oocytes were single-cultured to observe the following embryo quality of each PN stage.

RESULTS

Cycles with halo-positive oocytes showed a significant higher pregnancy rate (44.0% vs. 31.1%; p < 0.05). Furthermore, higher pregnancy rates in cycles with polarized nucleoli were observed. Polarized PN resulted in a significant lower fragmentation and higher cleavage rate of embryos. The fragmentation rate was significantly lower in halo+ oocytes, but the cleavage rate was not influenced.

CONCLUSIONS

The results indicate that the presence of a polarized zone of human fertilized oocytes can be a useful indicator for good oocyte quality. Since the origin of ooplasmic polarization seems to be a different process compared with the alignment of nucleoli, the observation will give additional predictive information about the implantation potential.

Comparison of stimulation with clomiphene citrate in combination with recombinant follicle-stimulating hormone and recombinant luteinizing hormone to stimulation with a gonadotropin-releasing hormone agonist protocol: a prospective, randomized study

OBJECTIVE

To compare IVF-ET outcome with a new stimulation protocol using clomiphene citrate (CC) with recombinant FSH and LH to stimulation with the standard long GnRH-a protocol.

DESIGN

Prospective randomized study.

SETTING

Outpatient infertility clinic in Vienna, Austria.

PATIENT(S)

Two hundred ninety-four infertile women undergoing IVF-ET; 154 IVF cycles stimulated with CC + recombinant FSH + recombinant LH (group A) and 140 cycles with long GnRH-a suppression + recombinant FSH (group B).

INTERVENTION(S)

Controlled ovarian hyperstimulation, egg retrieval, and ET.

MAIN OUTCOME MEASURE(S)

Cycle parameters (number of oocytes, fertilization, number of embryos) and outcome (pregnancy rate, cancellation rate, ovarian hyperstimulation syndrome [OHSS]).

RESULT(S)

Pregnancy rate per ET was 42.9% (implantation rate, 21.3%) in group A and 36.6% (17.4%) in group B. Cancellation rates were similar. The OHSS occurred in four cases (3%) in group A and 12 cases (10%) in group B.

CONCLUSION(S)

Stimulation with CC + recombinant FSH + recombinant LH leads to comparable pregnancy rates vs. the long protocol. With this new stimulation, less gonadotropins are used and there is less need for monitoring (lower cost for patient and clinic). The risk of OHSS is reduced as well. Therefore, this protocol should be regarded as the first-line treatment.

Luteal phase support using either Crinone 8% or Utrogest: results of a prospective, randomized study

The Crinone 8% preparation makes it possible to administer natural progesterone (90 mg) vaginally once daily for luteal phase support (LPS). Until now, no prospective, randomized studies have directly compared this new preparation with widely used Utrogest capsules, which were originally designed for oral administration but are used routinely as a vaginal preparation. A prospective, randomized study investigated 126 patients undergoing cycles of in vitro fertilization (IVF) and IVF/intracytoplasmic sperm injection (ICSI). Patients received either Crinone 8% (n = 73) vaginally once daily or two Utrogest capsules (n=53) vaginally three times daily (600 mg). Clinical pregnancy rates were comparable (28.8 versus 18.9%), as were clinical abortion rates until 12 weeks of gestation (14.3 versus 10.0%) and clinical ongoing pregnancy rates (24.7 versus 17.0%) in the Crinone 8% and Utrogest groups, respectively. Forty-seven non-pregnant patients were randomly selected to answer questions regarding comfort during LPS. Crinone 8% had a clear advantage over Utrogest as it resulted in less vaginal discharge (P < 0.01) and fewer application difficulties (P<0.05). Twenty patients familiar with the alternative preparation from a previous cycle also noted that Crinone 8% was easier to apply (P < 0.01) and less time consuming (P < 0.05) to use than Utrogest.

Young age does not protect against the adverse effects of reduced ovarian reserve--an eight year study

BACKGROUND

Ovarian reserve significantly influences IVF outcome. Low response to ovarian stimulation due to reduction of ovarian reserve is occasionally encountered in young women. The aim of this study was to evaluate the outcome of IVF treatment in young patients with reduced ovarian reserve.

METHODS AND RESULTS

Between January 1993-2001, 762 consecutive patients satisfied the definition of reduced ovarian reserve (raised early follicular phase FSH or gonadotrophin stimulation cycles where three or fewer oocytes were retrieved after routine FSH stimulation) and were included in the study. They were classified into three age groups: young (< or = 30 years), intermediate (31-38 years) and older (>38 years). The three age groups were similar with respect to basal (day 3) serum FSH and estradiol concentrations, cause of infertility and number of previous treatment cycles. Implantation (13, 9.6 and 9.8%), clinical pregnancy (11.8, 10.2 and 10%) and live birth (7.4, 7.3 and 6.8%) rates were not significantly different in the three age groups respectively (P > 0.05).

CONCLUSION

This study shows that younger patients with reduced ovarian reserve have a poor outcome of IVF treatment similar to their older counterparts. Such information may be helpful in counselling these patients who otherwise might anticipate an outcome related to their chronological age.

Successful pregnancy and delivery after testicular sperm extraction despite an undetectable concentration of serum inhibin B in a patient with nonobstructive azoospermia

OBJECTIVE

To describe a successful pregnancy and delivery after testicular sperm extraction (TESE) despite an undetectable concentration of serum inhibin B in a man with nonobstructive azoospermia.

DESIGN

Case report.

SETTING

Obstetrics and gynecology and reproductive biology departments.

PATIENT(S)

A 31-year-old woman and a 32-year-old man with nonobstructive azoospermia and an undetectable inhibin B serum level.

INTERVENTION(S)

TESE, testicular spermatozoa cryopreservation, intracytoplasmic sperm injection (ICSI).

MAIN OUTCOME MEASURE(S)

Pregnancy and delivery.

RESULT(S)

Successful pregnancy and delivery of a normal healthy child following a third ICSI cycle with frozen-thawed spermatozoa extracted from the testis.

CONCLUSION(S)

This case report shows that there is no minimal level of inhibin B below which TESE is always unsuccessful. The delivery of a normal healthy baby is strong evidence to perform TESE in these circumstances.

Prognostic implication of apoptosis in human luteinized granulosa cells during IVF-ET

PURPOSE

To investigate the prognostic significance of apoptosis in granulosa cells recovered from patients participating in IVF-ET.

METHODS

Seventy-three women underwent ovarian hyperstimulation for IVF and embryo transfer. After follicle aspiration, recovered granulosa cells were stained by BCL2 monoclonal antibody with FITC and propidium iodide (PI). Fluorescence was detected by flowcytometry, then the apoptotic index (Al) and BCL2 positivity were assessed.

RESULTS

The pregnant group showed a significantly lower apoptotic index in granulosa cells compared with the nonpregnant group (p < 0.0001). Patient's age, basal serum FSH concentration, serum E2 concentrations at hCG day, number of retrieved oocytes, fertilization rates. number of embryos transferred, and BCL2 positivity were not different between the two groups. Linear regression analysis of AI to serum basal FSH showed a positive correlation. Al in granulosa cells of 6.14% or below could predict a successful pregnancy with a sensitivity of 87.5% and a specificity of 73.7%.

CONCLUSION

Our results indicate that apoptotic analysis within granulosa cells can be used as a prognostic indicator for IVF success.

The role of expression of extracellular matrix proteins and epidermal growth factor receptor activity on fertilization capacity of testicular harvested spermatozoa

It has been suggested that multiple growth factors are crucial for spermatogenesis. We analyzed whether alterations on epidermal growth factor receptor activity and different expression pattern of extracellular matrix proteins had an impact on the fertilization capacity of spermatozoa and pregnancy rate after testicular sperm extraction and intracytoplasmic injection. Extracellular matrix proteins and epidermal growth factor receptor were immunohistochemically evaluated in testis of 88 patients with nonobstructive azoospermia. Testicular sperm extraction and intracytoplasmic injection procedure was also performed in 32 of the patients for whom mature sperm could be harvested from the testicular tissue. While collagen Type-IV and laminin activity percentages were 33.1% and 86.4% in motile sperm harvested testicular tissue, these activities were 23.3% and 89.3% in immotile sperm harvested testicular tissue, respectively. In addition, the mean epidermal growth factor receptor expression was higher in immotile than motile sperm obtained tissue (56.4% vs. 51.1%, P=0.4928). There was no statistically significant relationship between the extracellular matrix protein and epidermal growth factor receptor expression patterns and sperm motility, fertilization and pregnancy rates in testicular sperm extraction and intracytoplasmic injection. However, further studies are required to investigate the relationship between other growth factors and sperm fertilization capacity.

Comparison of cryopreservation outcome with gonadotropin-releasing hormone agonists or antagonists in the collecting cycle

OBJECTIVE

To compare the pregnancy rates of frozen-thawed 2-pronucleate (2PN) oocytes obtained either in a long protocol or in an antagonist protocol and ovarian stimulation with either human menopausal gonadotropin (hMG) or recombinant follicular stimulating hormone (recFSH).

DESIGN

Retrospective data analysis.

SETTING

Academic infertility center.

PATIENT(S)

Three hundred forty-two infertile couples who underwent a transfer of cryopreserved 2PN oocytes.

INTERVENTION(S)

hMG (n = 194) or recFSH (n = 92) in a long protocol or hMG (n = 16) or recFSH (n = 40) stimulation under pituitary suppression with the GnRH antagonist Cetrotide was used. The 2PN oocytes were transferred after endometrial preparation using E(2) valerate and vaginal progesterone (Crinone 8% vaginal gel).

MAIN OUTCOME MEASURE(S)

Implantation, pregnancy, and abortion rates.

RESULT(S)

Implantation rates in the freeze-thaw cycles were 5.6% (hMG) and 3.8% (recFSH) with 2PN oocytes from the long protocol and 7% from the antagonist cycles, irrespective of whether hMG or recFSH was used. Pregnancy rates were similar independent of whether they resulted from the long-protocol cycles with hMG (15.4%) and recFSH (13.1%) or from the antagonist protocol cycles with hMG (25.0%) and recFSH (17.5%).

CONCLUSION(S)

The potential to implant is independent of the gonadotropin-releasing hormone analogue and gonadotropin chosen for the collection cycle when previously cryopreserved 2PN oocytes were replaced after thawing in the cleavage stage.

High rates of embryonic loss, yet high incidence of multiple births in human ART: is this paradoxical?

Humans have low natural fecundity, as the probability of establishing a viable conception in any one menstrual cycle is 20-25% for a healthy, fertile couple. There are numerous underlying causes for this low rate of human fertility, not the least of which are intrinsic abnormalities within the oocyte and/or embryo, which likely account for greater than 50% of failed conceptions. During assisted reproduction technology (ART) interventions, controlled ovarian stimulation is used to obtain several oocytes in attempts to increase the likelihood of having at least one developmentally competent embryo available for transfer. However, current techniques for identifying the competent embryo(s) are by no means perfect. These limitations, coupled with pressures to maximize the chance of pregnancy, typically result in the transfer of multiple embryos. Not surprisingly, this practice has resulted in an unacceptably high rate of multiple pregnancies arising from ART. During the last few years, concerted efforts have focused on reducing these rates. Programs for ART are developing patient-specific policies, restricting the number of embryos to transfer. In addition, strategies are being adopted to improve the accuracy for selecting viable embryos for transfer. One such strategy involves further refinement of morphological criteria associated with improved viability by considering, for example, pronuclei disposition, nucleolar organization, and identification of the fast-cleaving embryos with only mononucleate blastomeres. Another strategy employs pre-implantation genetic diagnosis (PGD) whereby a biopsied blastomere is tested for ploidy using fluorescence in situ hybridization (FISH). A final strategy involves extending the duration of culture to the blastocyst stage, thereby allowing self-selection of those embryos capable of proceeding to blastulation and exclusion of those less viable embryos that succumb to developmental arrest. Together, these strategies are enabling fewer embryos of higher quality to be transferred. Accordingly, the overall pregnancy rate from ART continues to increase, while the rate of triplet and higher order multiple births continues to decline. Nevertheless, the high incidence of intrinsic developmental anomalies in human oocytes inevitably will continue to result in a high degree of embryonic loss in ART.

Early embryo cleavage is a strong indicator of embryo quality in human IVF

BACKGROUND

In order to decrease multiple birth rates without decreasing birth rates overall, it is important to increase the capability of selecting the most optimal embryos for transfer. It has been shown that human embryos which cleave early, i.e. complete the first mitotic division within 25-27 h post insemination, provide higher pregnancy and implantation rates.

METHODS AND RESULTS

In this prospective study, an evaluation of 10 798 scored embryos showed that early cleavage resulted in a significantly higher proportion of good quality embryos compared with late cleavage (62.5 versus 33.4%, P < 0.0001). When examining both day 2 and day 3 transfers together, early-cleaving embryos (306 transfers) gave rise to significantly higher rates of pregnancy/transfer (40.5 versus 31.3%, P = 0.0049), implantation (28.0 versus 19.5%, P = 0.0001) and birth/ongoing pregnancy (34.3 versus 24.0%, P = 0.0009) than did late-cleaving embryos (521 transfers). A stepwise logistic regression of all data showed that the total number of good quality embryos and female age were independent predictors of both pregnancies and birth. For intracytoplasmic sperm injection (ICSI) embryos, early cleavage was found to be an independent predictor of birth.

CONCLUSIONS

Early embryo cleavage is a strong biological indicator of embryo potential, and may be used as an additional embryo selection factor for ICSI embryos.

In vitro maturation and fertilization of oocytes from unstimulated normal ovaries, polycystic ovaries, and women with polycystic ovary syndrome

OBJECTIVE

To investigate differences in immature oocyte maturation, fertilization, and pregnancy rates among women with unstimulated normal ovaries, polycystic ovaries (PCOs), or PCOS.

DESIGN

Prospective observational study.

SETTING

University fertility clinic.

PATIENT(S)

One hundred forty-four women undergoing 180 in vitro oocyte maturation treatment cycles.

INTERVENTION(S)

Transvaginal immature oocyte recovery from unstimulated ovaries 36 hours after hCG priming. In vitro oocyte maturation and fertilization. Fresh embryo transfer.

MAIN OUTCOME MEASURE(S)

Immature oocytes collected, metaphase II oocytes, and embryos produced. Implantation and pregnancy rates.

RESULT(S)

The overall oocyte maturation and fertilization rates attained were 80.3% (1,222 of 1,522) and 76.5% (935 of 1,222), respectively. Significantly fewer immature oocytes were retrieved from normal ovaries (5.1 +/- 3.7) compared with the PCO (10.0 +/- 5.1) or PCOS (11.3 +/- 9.0) groups. Fertilization and cleavage rates were comparable among the three groups. The implantation, pregnancy, and live birth rates per transfer for normal ovaries were 1.5%, 4.0%, and 2.0%, respectively; for PCOs 8.9%, 23.1%, 17.3%, respectively; and for women with PCOS 9.6%, 29.9%, and 14.9%, respectively.

CONCLUSION(S)

Immature oocytes retrieved from normal ovaries, PCOs, or women with PCOS, when using hCG priming before oocyte retrieval, have a similarly high maturation, fertilization, and cleavage potential. In vitro maturation is a useful treatment option, particularly for women with PCOs.

Evaluation of pronuclear morphology as the only selection criterion for further embryo culture and transfer: results of a prospective multicentre study

BACKGROUND

The aim was to study zygote evaluation based on pronuclear morphology under the German embryo protection law, according to which only a maximum of three zygotes are allowed to be cultured for embryo transfer.

METHODS

In this prospective multicentre study, a total of 512 treatment cycles was performed at 10 centres, between November 1999 and October 2000. Zygotes were classified into seven patterns (0A, 0B and 1-5). Pattern 0A and 0B zygotes were preferentially used for further culture and transfer.

RESULTS

Cycles with transfer of at least one embryo derived from pattern 0B, but not pattern 0A, resulted in significantly higher pregnancy (37.9%) and implantation rates (20.5%) compared with non-pattern 0B cycles (26.4 and 15.7%; P < 0.05 and P < 0.01 respectively). In younger patients (aged < or =35 years), significantly more 0B zygotes were available for transfer than in older patients (34.2 versus 25.8%; P < 0.005).

CONCLUSIONS

From these data, it is concluded that evaluation of pronuclear morphology is beneficial, especially for countries with legal restrictions regarding embryo selection.

A prospective controlled study of the effect of intramural uterine fibroids on the outcome of assisted conception

BACKGROUND

Although uterine fibroids occur in 30% of women and are associated with a degree of subfertility, the effect of intramural fibroids on the outcome of IVF or ICSI treatment has not been prospectively studied.

METHODS

Data were prospectively collected on 434 women undergoing IVF/ICSI in the assisted conception unit of an inner London teaching hospital. Patients were assessed for the presence of fibroids by transvaginal ultrasound and hysterosonography or hysteroscopy where appropriate.

RESULTS

During the study period, 112 women with (study), and 322 women without (controls), intramural fibroids were treated. Patients were similar regarding the cause and duration of their infertility, number of previous treatments, and basal serum FSH concentration. Women in the study group were on average 2 years older (36.4 versus 34.6 years; P < 0.01). There was no significant difference in the duration of ovarian stimulation or gonadotrophin requirement, number of follicles developed, oocytes collected, embryos available for transfer or replaced. When analysing only women with intramural fibroids of < or =5 cm in size (n = 106) pregnancy, implantation and ongoing pregnancy rates were significantly reduced: 23.3, 11.9 and 15.1 respectively compared with 34.1, 20.2 and 28.3% in the control group (P = 0.016, P = 0.018 and P = 0.003). The mean size of the largest fibroids was 2.3 cm (90% range 2.1-2.5 cm). Logistic regression analysis demonstrated that the presence of intramural fibroids was one of the significant variables affecting the chance of an ongoing pregnancy, even after controlling for the number of embryos available for replacement and increasing age, particularly age > or =40 years, odds ratio 0.46 (CI 0.24-0.88; P = 0.019).

CONCLUSION

This study demonstrated that an intramural fibroid halves the chances of an ongoing pregnancy following assisted conception.

Gonadotropin-releasing hormone antagonist protocol: a novel method of ovarian stimulation in poor responders

OBJECTIVE

To estimate the efficacy of gonadotropin-releasing hormone (GnRH) antagonist 'Cetrorelix' in poor responders comparing with the standard long protocol.

DESIGN

The study population consisted of 21 poor responders who underwent ICSI and treated with Cetrorelix according to the multiple-dose protocol and who were compared with 21 poor responders treated according to the long protocol and who also underwent ICSI. Patients in both groups were matched for chronological age, the number of follicles found by ultrasound at the retrieval day and cause of infertility. Fifteen patients of GnRH antagonist group were treated with the combination of GnRH antagonist with clomiphene citrate (CC) plus gonadotropins, while six patients were treated with the combination of GnRH antagonist plus gonadotropins, but without CC.

RESULTS

The use of GnRH antagonist in a multiple dose protocol gave a pregnancy rate of 14.28% which was in the range expected for patient with poor response, but with shorter treatment duration and with fewer ampoules of gonadotropins as compared with the use of a GnRH agonist protocol in a depot formulation. Within Cetrorelix group patients who received CC had a significant shorter duration of stimulation and needed fewer ampoules as compared with patients in the same group who did not receive CC.

CONCLUSIONS

A GnRH antagonist multiple dose protocol may be the protocol of choice for the treatment of poor responders. The use of GnRH antagonist Cetrorelix ended with significantly less ampoules of gonadotropins and a shorter duration of stimulation.

Embryo fragmentation in vitro and its impact on treatment and pregnancy outcome

OBJECTIVE

To determine the impact of embryo fragmentation on pregnancy, obstetric, and perinatal outcome.

DESIGN

Retrospective analysis of embryo transfers that were homogeneous in regard to the degree of fragmentation.

SETTING

Fertility center.

PATIENT(S)

A cohort of 460 fresh embryo transfers.

INTERVENTION(S)

A total of 164 pregnancies were analyzed for the incidence of antepartum complications during gestation, obstetric (multiple pregnancy, preterm delivery, cesarean section), and perinatal outcome (sex, birth weight, admission to neonatal intensive care unit, malformations).

MAIN OUTCOME MEASURE(S)

Implantation and clinical pregnancy rate, obstetric and perinatal outcome.

RESULT(S)

Embryo fragmentation and number of embryos per transfer showed a significant influence on clinical pregnancy and implantation rate. No such relation was found concerning complications, multiple pregnancy rate, incidence of cesarean section, gestation week, birth weight, and average time at the neonatology. On the other hand, pregnancies derived from bad-quality embryos had a significantly higher rate of malformations.

CONCLUSION(S)

The higher percentage of malformations found in bad-quality embryos may be due to a higher percentage of apoptotic features and chromosomal disorders. For ethical reasons, the transfer of embryos with >50% fragmentation should be considered only after consultation with the patient.

Multiple gestations in assisted reproductive technology: can they be avoided with blastocyst transfers?

OBJECTIVE

Blastocysts are advanced-stage embryos with high implantation potential; theoretically, limited numbers of blastocysts can be used for embryo transfer to achieve good pregnancy rates with low multiple pregnancy rates. Clinical outcomes of a newly implemented blastocyst transfer program were evaluated.

STUDY DESIGN

This study is a retrospective analysis of 553 blastocyst transfer cycles performed by a university-based in vitro fertilization program; risk factors associated with multiple gestations were analyzed.

RESULTS

An average of 2.2 embryos were used for embryo transfer. The overall clinical pregnancy rate per embryo transfer was 45.1%; multiple gestation, twin, and triplet rates were 40.9%, 36.5%, and 4.3%, respectively. Multiple gestations increased significantly (1) when embryo transfer was done on day 5, (2) when > or =2 blastocysts were present on day 5, and (3) when maternal age was < or =30 years.

CONCLUSION

In spite of a conservative approach to the number of blastocysts used for embryo transfer, the overall multiple pregnancy rate was high, and triplet pregnancies did occur.

Embryo selection by the first cleavage parameter between 25 and 27 hours after ICSI

PURPOSE

The objective of this study was to assess first embryo cleavage (FEC) 25-27 h after intracytoplasmic sperm injection (ICSI) as a parameter for the embryo selection process.

METHODS

From January 1998 to December 1999, a total of 670 patients were subjected to the ICSI programme at the Centre for Human Reproduction, Sinhá Junqueira Maternity Foundation, and the FEC parameter was evaluated in three situations.

RESULTS

In the first, a total of 300 zygotes were analyzed on the basis of a score (16-18 h after ICSI) and observed for the presence or absence of FEC (25-27 h after ICSI). A significant (p < 0.02) presence of FEC was observed in zygotes with a score of 15 (ideal score). In the second, a total of 200 patients were selected and divided into two groups matched for age and laboratory performance. Group I (n = 100) was subjected to transfer of embryos with the absence of FEC only (since in this cycle no embryos with FEC were detected within 25-27 h after ICSI) and Group II (n = 100) was subjected to transfer of embryos with the presence of FEC only. The age of Group I patients (33.8 +/- 4.2 years) did not differ significantly (p = 0.50) from that of Group II patients (33.5 +/- 4.3 years). The number of embryos transferred was similar (p = 0.07) for Group I (2.7 +/- 1.1) and Group II (2.9 +/- 0.88). In Group II, the 17.5% implantation rate was significantly higher (p < 0.01) than the 5.9% rate obtained for Group I. The pregnancy rate for Group II was significantly higher (p < 0.01) (33%) than that for Group I (12%). The incidence of abortion was 16.6% in Group I as compared with 6% in Group II. In the third situation, we observed the frequency of embryos with FEC in 36 patients whose implantation rate was 100% (ideal result) and obtained a value of 82%.

CONCLUSIONS

The data suggest that the presence of the FEC parameter that was evaluated 25-27 h after ICSI could be used to select embryos with a higher implantation power. The data reported here may justify routine analysis of embryos with FEC for the process of embryo selection after ICSI.

Evaluation of the meiotic spindle apparatus in metaphase II human oocytes following cytoplasmic donation

PURPOSE

To determine if the removal of cytoplasm from metaphase II human donor oocytes damages the meiotic spindle apparatus.

MATERIALS AND METHODS

Cryopreservation of metaphase II human oocytes was performed using a fast-freeze, fast-thaw protocol. Upon thaw, oocytes were incubated for 3-4 h and then used for cytoplasmic donation (test oocytes). Oocytes thawed but not used for donation served as controls. Test and control oocytes were fixed using a microtubule-stabilizing buffer. Tubulin was localized using antitubulin monoclonal antibody. Chromosomes were identified by counterstaining with DAPI.

RESULTS

Forty-four oocytes had cytoplasm removed (test group) while 12 were not used for the procedure (controls). Twenty-three oocytes survived the donation procedure. Rates of normal spindle structure for the control and test groups were 21/23 (91.3%) and 12/12 (100%), respectively.

CONCLUSION

The removal of cytoplasm from a metaphase II human donor oocyte does not appear to significantly increase the damage to chromosome alignment or to the spindle structure.

IVF-patients with nonmale factor "to ICSI" or "not to ICSI" that is the question?

PURPOSE

Intracytoplasmic sperm injection (ICSI) guarantees high fertilization rates and could theoretically lead to higher implantation rates as well. Furthermore injection into oocyte creates a hole in the zona pellucida similar to the procedure of assisted hatching. We were therefore interested to assess such a potential benefit for infertile IVF patients without male factor.

MATERIALS AND METHODS

Open randomized prospective study according to the rules "Good Clinical Practice" with informed consent of the patients and institutional review board approval. Ninety-one consecutively seen patients with tubal infertility or hostile cervical mucus were randomized to undergo either ICSI (44 patients) or IVF (45 patients). In two patients fertilization of oocytes failed and so a repeated ICSI had to be performed. All these patients were stimulated with the same protocol, using the gonadotropin releasing hormone-agonist (GnRH-a) buserelin acetate in an ultrashort flair-up protocol together with pure follicle stimulating hormone (rFSH). The two study groups did not differ in terms of age, BMI, and all baseline hormone levels.

RESULTS

The total pregnancy rate was 42% in the normal IVF group with 33% ongoing pregnancies. The ICSI group had a total pregnancy rate of 39% with 23% ongoing pregnancies. The implantation rate per transferred embryo was higher for normal IVF but not significant (18% versus 11%). The variables, fertilization rate, age, body mass index, baseline hormone levels, endometrial thickness, embryo score, and the highest grade embryo per transfer were very similar in both groups.

CONCLUSION

ICSI should be applied only when conventional IVF fails, that is, for male factor patients and for patients with unexplained infertility.

Embryo score is a better predictor of pregnancy than the number of transferred embryos or female age

OBJECTIVE

To compare the value of 17 IVF variables, including a new mean score of transferred embryos (MSTE), in predicting pregnancy rate.

DESIGN

Retrospective study.

SETTING

Private IVF unit.

PATIENT(S)

Women who underwent 10,000 embryo transfers.

MAIN OUTCOME MEASURE(S)

Duration of infertility, type of infertility, female age, rank of IVF attempt, type of ovarian treatment, progesterone level, sperm count, sperm motility, sperm morphology, number of retrieved oocytes, number of mature oocytes, maturation rate, number of embryos obtained, fertilization rate, number of transferred embryos, cumulative embryo score (CES), mean score of transferred embryos (MSTE), and pregnancy rate.

RESULT(S)

Outcome of IVF-ET was significantly correlated with female age, type of infertility, number of retrieved oocytes, number of mature oocytes, maturation rate, embryos obtained, fertilization rate, transferred embryos, CES, and MSTE. Multivariate analysis demonstrated that MSTE was a better predictor of pregnancy than the number of transferred embryos and female age.

CONCLUSION(S)

Embryo quality is the best predictor of pregnancy. The embryo score described herein should be used in IVF-ET programs to choose the best embryos for transfer.

Endometrial receptivity in an in vitro fertilization program as assessed by spiral artery blood flow, endometrial thickness, endometrial volume, and uterine artery blood flow

OBJECTIVE

To investigate the role of sonographic parameters in assessing endometrial receptivity in an in vitro fertilization (IVF) program.

DESIGN

Prospective clinical study.

SETTING

University setting.

PATIENT(S)

One hundred thirty-five patients in our IVF program, selected prospectively on the day of oocyte retrieval.

INTERVENTION(S)

Transvaginal ultrasound examination was performed before oocyte collection.

MAIN OUTCOME MEASURE(S)

Association between implantation rate and spiral artery blood flow (primary outcome measure) and between implantation rate and endometrial measurements as well as uterine artery blood flow (secondary outcome measures).

RESULT(S)

Overall implantation rate was 23.7% per cycle. Subendometrial blood flow was detected in 113 (83.7%) cases, with pregnancy occurring in 21.2%. Mean spiral artery pulsatility index values were 1.12 +/- 0.28 and 1.21 +/- 0.27 for nonconception and conception cycles, respectively. Nondetectable spiral artery blood flow was not associated with a lower implantation rate. Neither endometrial thickness nor endometrial volume was correlated with the likelihood of successful implantation. Minimum endometrial thickness and volume associated with pregnancy were 6.9 mm and 1.59 mL, respectively.

CONCLUSION(S)

Neither Doppler sonography of the spiral or uterine arteries nor measurement of the endometrial thickness or volume allowed a reliable prediction of subsequent IVF outcome.

Embryo quality and developmental potential is compromised by age

AIMS

The aim of this retrospective study was to assess whether and how the age of the woman affects the quality and developmental potential of the oocytes and embryos in an ART program.

METHOD AND MATERIAL

A total of 878 IVF cycles was included as a consecutive series of single transfers (n=292), dual transfers (n=366) and triple transfers (n=220), where all the transferred embryos in each cycle were of identical quality score and identical cleavage stage.

RESULTS

We found a highly significant decrease in oocyte recovery with increasing age with about one oocyte per 2.3 years (95% CI 1.8 years to 3.1 years, p<0.0001). Further, we found that the number of oocytes that cleaved declined significantly with increasing age with one per 3.7 years (95% CI 2.7 years to 5.5 years, p<0.0001). This decline was mainly due to the decline in number of oocytes retrieved as the ratio of aspirated oocytes that cleaved with increasing age (approx. -0.04/10 year 95% CI: -0.10; +0.009) was not significantly different (p=0.10). The percentage of transfers using fragmented embryos did not increase significantly with increasing age (p=0.08). The odds of fragmentation increased by 3% per year. The average number of embryos transferred decreased significantly (p=0.03) with age from approximately 2.1 at the age of 25 to approximately 1.8 at the age of 40. In a selected subgroup of embryos all consisting of good quality embryos, a significant decrease was found in implantation rate with increasing age (approx. -0.08/10 years, 95% CI: -1.6; +0.00, p=0.05). Of the 357 pregnancies achieved in this study we found a significantly decreased ongoing pregnancy rate and a significantly increased abortion rate with increasing age (p=0.03). The decrease in the rate of ongoing pregnancies was almost linear, decreasing by approximately 1.5% per year.

CONCLUSIONS

We conclude that age has an impact throughout a woman's reproductive life and that it is important to realize that the age-related decline in fertility may start already in the late twenties and not in the mid-thirties as is generally assumed.

Freezing a few testicular spermatozoa retrieved by TESA

Men with azoospermia can now be treated using testicular sperm aspiration (TESA). New aspirations, in subsequent cycles, may be avoided using cryopreservation. Conventional sperm freezing techniques are not suitable for TESA samples with a small number of spermatozoa. Testicular spermatozoa were obtained from 10 azoospermic men undergoing TESA for a diagnostic objective. Two different freezing protocols were performed according to the number of spermatozoa found in the final suspension: between 100-2000, we used TEST yolk buffer with glycerol, adding it to testicular sperm (Method I); for less than 100, we injected them into cell-free human zona pellucida before adding a freezing medium (Method II). Sperm and motility recovery rates were 1% and 32.3%, and 88.2% and 26.6% for methods I and II respectively. The fertilisation rate was 13.3% and 23% for methods I and II respectively. This study represents our preliminary experience in freezing testicular spermatozoa collected by TESA. Preliminary observations show that it is possible to freeze a few testicular spermatozoa inside evacuated zona pellucida.

Prospective randomized study of two cryopreservation policies avoiding embryo selection: the pronucleate stage leads to a higher cumulative delivery rate than the early cleavage stage

OBJECTIVE

To compare the cumulative live birth rates obtained after cryopreservation of either pronucleate (PN) zygotes or early-cleavage (EC) embryos.

DESIGN

Prospective randomized study.

SETTING

University hospital.

PATIENT(S)

Three hundred eighty-two patients, involved in an IVF/ICSI program from January 1993 to December 1995, who had their supernumerary embryos cryopreserved either at the PN (group I) or EC (group II) stage. For 89 patients, cryopreservation of EC embryos was canceled because of poor embryo development (group III). Frozen-thawed embryo transfers performed up to December 1998 were considered.

MAIN OUTCOME MEASURE(S)

Age, oocytes, zygotes, cryopreserved and transferred embryos, damage after thawing, cumulative embryo scores, implantation, and cumulative live birth rates.

RESULT(S)

The clinical pregnancy and live birth rates were similar in all groups after fresh embryo transfers. Significantly higher implantation (10.5% vs. 5.9%) and pregnancy rates (19.5% vs. 10.9%; P< or = .02 per transfer after cryopreserved embryo transfers were obtained in group I versus group II, leading to higher cumulative pregnancy (55.5% vs. 38.6%; P < or = .002 and live birth rates (46.9% vs. 27.7%; P< or = .0001.

CONCLUSION(S)

The transfer of a maximum of three unselected embryos and freezing of all supernumerary PN zygotes can be safely done with significantly higher cumulative pregnancy chances than cryopreserving at a later EC stage.

Effects of functional ovarian cysts detected on the 7th day of gonadotropin-releasing hormone analog administration on the outcome of IVF treatment

OBJECTIVE

To investigate the impact of functional ovarian cysts on the time required to achieve pituitary suppression, follicular development, embryo quality, and pregnancy rates during IVF treatment.

DESIGN

Prospective observational study.

INTERVENTION(S)

Daily treatment with buserelin (sc 500 microg) was initiated on day 2 of menstruation. Ultrasound and hormonal tests were performed on days 1, 7, 11, 14, and weekly thereafter until pituitary suppression was achieved.

RESULT(S)

48 patients underwent 51 cycles of IVF treatment. A functional cyst was detected in three cycles (5.8%) with baseline ultrasound scan and in 27 cycles (52.9%) on day 7 of buserelin administration. Patients who developed a cyst required a significantly longer time to achieve pituitary suppression (21 vs. 7 days), had a significantly lower FSH level at the time of initiation of gonadotropins, required more ampules of gonadotropin (45 vs. 41 ampules), developed less follicles (13 vs. 17.5), and had lower embryo quality. However, there were no differences in the implantation (23.5% vs. 17.2%) and pregnancy rates (37.2% vs. 29.2%) between two groups.

CONCLUSION(S)

Functional cysts prolong the period to achieving pituitary suppression, increase gonadotropin requirements, and decrease follicular recruitment and embryo quality. They have, however, no negative effect on pregnancy rates.

Zona thinning with noncontact diode laser in patients aged < or = 37 years with no previous failure of implantation: a prospective randomized study

PURPOSE

Zona thinning (ZT) is a technique used to improve pregnancy rates among patients > or = 38 years old and/or patients presenting previous implantation failure. The objective of the study was to determine whether ZT has a beneficial effect on patients younger than 37 years who are undergoing the first ICSI attempt.

METHODS

A total of 103 patients submitted to ICSI for the first time and those aged < or = 37 years were divided in a prospective and randomized manner into two groups: group I, patients submitted to ZT (n = 51) (a laser diode with 1.48-micron wavelength (Fertilaser) was used for the procedure); group II, patients with no ZT (n = 52). In both groups, embryo transfer was performed on the second day.

RESULTS

The age of group I patients (31.8 +/- 3.6) did not differ (P = 0.53) from that of group II patients (31.4 +/- 3.6). The number of metaphase II oocytes was similar (P = 0.76) for the two groups (group I = 9.12 +/- 5.27; group II = 8.67 +/- 5.02). The average number of embryos available per transfer of group I (6.14 +/- 4.02) did not differ (P = 0.69) from that of group II (5.75 +/- 3.83). The number of embryos transferred was similar (P = 0.61) for the two groups (group I = 2.76 +/- 0.9; group II = 2.87 +/- 0.79). The thickness of the zona pellucida of group I embryos (16.6 +/- 2.2 microns) did not differ (P = 0.08) from that of group II embryos (17.1 +/- 1.7 microns). The rate of embryo implantation (20.8%) and the rate of clinical pregnancy per embryo transfer (40.3%) were higher for group II than for group I (17.7% and 33.3%, respectively), but the difference was not significant (P = 0.55 and P = 0.54).

CONCLUSIONS

These results suggest that ZT in the population aged < or = 37 years and with no previous failure of implantation may have no impact on intracytoplasmic sperm injection success rates.

Number and size of antral follicles as predictive factors in vitro fertilization and embryo transfer

PURPOSE

The purpose of the study was to evaluate whether number and size of antral follicles can predict the outcome of in vitro fertilization-embryo transfer.

METHODS

A total of 113 patients were prospectively included into this study. After 19 days of down-regulation, number and size of follicles were determined by using recent three-dimensional transvaginal ultrasound technology. Before application of gonadotropin, all follicles had been defined as antral follicles. According to size, antral follicles were categorized into four different groups: group I included antral follicles < 5 mm, group II follicles 5-10 mm; group III 11-20 mm; and group IV > 20 mm. Pregnant and non-pregnant patients were compared in terms of their number of antral follicles of group I-IV. These four groups were then compared regarding implantation rate, number of retrieved oocytes, endometrium thickness, and age.

RESULTS

Pregnant patients showed an significant higher number of follicles with the size between 5 and 10 mm (P = 0.04). A significant correlation was found between number of retrieved oocytes and antral follicle size of 5-10 mm (P = 0.0001). Antral follicles with a diameter between 5 and 10 mm decreased significantly with age (P = 0.008). In group III and IV, a significant correlation was found between antral follicle size (P = 0.016) and serum estradiol level after gonadotropin-releasing hormone-agonist down-regulation (P = 0.011).

CONCLUSIONS

We demonstrated that patients with a higher number of follicles between 5 and 10 mm showed a significantly higher pregnancy rate, whereas patients with a dominant number of antral follicles > 11 mm have a higher cancellation rate due to ovarian low response.

Blastocyst score affects implantation and pregnancy outcome: towards a single blastocyst transfer

OBJECTIVE

To determine the relationship between blastocyst score and pregnancy outcome.

DESIGN

Retrospective review of blastocyst transfer in an IVF clinic.

SETTING

Private assisted reproductive technology unit.

PATIENT(S)

107 patients undergoing blastocyst culture and transfer of two embryos.

INTERVENTION(S)

Culture of all pronucleate embryos in sequential media to the blastocyst stage (day 5), followed by transfer of two blastocysts.

MAIN OUTCOME MEASURE(S)

Implantation rates, pregnancy rates, and twinning were analyzed.

RESULT(S)

When a patient received two top-scoring blastocysts (64% of patients), implantation and pregnancy rates were 70% and 87%, respectively. The twinning rate in this group was 61%. When only one top-quality blastocyst was available for transfer (21% of patients), the implantation and pregnancy rates were 50% and 70%. The twinning rate for this group was 50%. In contrast, when only low-scoring blastocysts were available for transfer (15% of patients), implantation and pregnancy rates were 28% and 44%, and the twinning rate was 29%. No monozygotic twins were observed in this group of patients.

CONCLUSION(S)

The ability to transfer one high-scoring blastocyst should lead to pregnancy rates greater than 60%, without the complication of twins.

Influence of female age on pregnancy outcome in in vitro fertilization and embryo transfer patients undergoing intracytoplasmic sperm injection

PURPOSE

To determine the influence of female age on the outcomes of ICSI in IVF-ET patients.

METHODS

One hundred and seventy-five couples underwent 352 cycles of ICSI. The quality of oocytes and embryos, fertilization rate, and pregnancy outcomes were retrospectively evaluated according to female age; < 30 years in Group A (49 cycles), 30-34 in Group B (177 cycles), 35-39 in Group C (97 cycles), and > or = 40 in Group D (29 cycles).

RESULTS

The fertilization rates were not significantly different among the age groups. Significant negative linear correlations were observed between female age and the numbers of oocytes retrieved and embryos transferred, and cumulative embryo score. Clinical pregnancy rates were significantly decreased and spontaneous abortion rate increased with advancing age.

CONCLUSIONS

Female age may be a prognostic indicator in ICSI program.

Implantation rates after in vitro fertilization and transfer of a maximum of two embryos that have undergone three to five days of culture

OBJECTIVE

To evaluate implantation and pregnancy rates in patients undergoing IVF after the transfer of a maximum of two embryos that had been cultured for 3-5 days.

DESIGN

Prospective study.

SETTING

An IVF laboratory at a tertiary referral university hospital.

PATIENT(S)

One thousand seven hundred eighty-seven couples who underwent their first IVF cycle between January 1995 and December 1997.

INTERVENTION(S)

In vitro fertilization and transfer of embryos after 3, 4, or 5 days of culture using a single medium without coculture.

MAIN OUTCOME MEASURE(S)

Implantation and pregnancy rates.

RESULT(S)

Overall implantation and pregnancy rates were not significantly different with different culture periods. Forty-one percent of all available embryos developed into blastocysts on day 5. The transfer of at least one good-quality blastocyst could be performed in 62% of patients. Blastocysts had an implantation rate of 26% per embryo, whereas the implantation rate of eight-cell embryos on day 3 was 18%. Implantation rates for retarded, normal, and advanced embryos were not significantly different with an extended culture period.

CONCLUSION(S)

Under the study conditions, the transfer of embryos after 5 days rather than 3 days of embryo culture did not change the overall implantation and pregnancy rates. The implantation potential of embryos available for transfer can be assessed better after an extended culture period. Five days of culture allows the transfer of a reduced number of embryos without decreasing overall pregnancy rates.