Male factor as determinant of in-vitro fertilization outcome.

The effect of different semen parameters was evaluated in 200 consecutive couples in an in-vitro fertilization (IVF) programme. All semen analyses were performed on the native aliquot of semen which was subsequently prepared and used for in-vitro insemination. Morphology evaluation using strict criteria (kappa 0.46 and r = 0.565) was compared with progressive motile sperm density (kappa 0.37 and r = 0.333) and the conventional World Health Organisation (WHO) evaluation of morphology (kappa 0.31 and r = 0.378). Results show that morphology evaluation using strict criteria is the best predictor of IVF and density of progressively motile spermatozoa can be an optional method. The combined results of strict morphology and motile concentration progressively showed that if both parameters were below the cut-off points of 5% and 3 x 10(6)/ml respectively, the fertilization rate per oocyte was very low (18%). No pregnancies were achieved in this group. When both parameters were above the cut-off points, the fertilization rate per oocyte was high (72%) (P less than 0.005) and the pregnancy rate per embryo transfer was 27%. Predictive values indicate that morphology evaluation using strict criteria and the number of progressive motile spermatozoa can be used as patient selection criteria for infertility clinics.     

Sperm treatment with extracellular ATP increases fertilization rates in in-vitro fertilization for male factor infertility

Previous work from our laboratory has revealed that extracellular ATP is a rapid and potent activator of human sperm acrosome reaction and fertilizing ability. In the present study, we assessed the effects of in-vitro sperm incubation with ATP on fertilization and embryo development in couples undergoing in-vitro fertilization (IVF) for male factor infertility. Oocytes from 22 women undergoing ovulation induction were divided in two groups and inseminated in vitro either with selected spermatozoa from the corresponding partner suffering from male factor infertility pre-incubated with ATP (2.5 mM) for 1 h, or with spermatozoa incubated with 0.9% NaCl solution (control group). After insemination, fertilization was assessed by the presence of pronuclei and then by embryo cleavage. The fertilization rate in the group of oocytes inseminated with ATP-treated spermatozoa improved significantly with respect to the control group (65.7 versus 42.5%, P < 0.01). No significant differences were observed in embryo cleavage and embryo quality. Embryos from both treated and control groups were transferred together in 20 transfer procedures, and in two couples fertilization was not obtained. Nine pregnancies occurred: one biochemical, one miscarriage, and seven patients delivered 9 healthy babies. Two pregnancies were twin with an overall pregnancy rate of 40.9% per cycle and of 45% per transfer. In conclusion, the results of the present study demonstrate that, in humans, extracellular ATP induces a significant increase of sperm fertilizing potential, as these findings are a rationale for the use of ATP for in-vitro treatment of human spermatozoa during IVF.     

Andrology: Semen parameters as predictors of in-vitro fertilization: the importance of strict criteria sperm morphology

This study evaluated 120 couples undergoing in-vitro fertilizationtreatment to determine which semen parameter(s) predicted fertilizationand whether there was any consistent relationship between strictcriteria and standard assessment of sperm morphology. Strictcriteria morphology was the only significant predictor of fertilization(P = 0.0006, r² = 0.09), with a sensitivity of 94% and a specificityof 40%. A 12% cut-off point presented a negative predictivevalue of 98% and a positive predictive value of 22%. The probabilityof satisfactory fertilization is 40% with morphology <4%,which increases to 97% with normal morphology (12%). The receiveroperating characteristic curve deviated significantly from thediagonal with a 76% area wider the curve, making this a superiorpredictive test. This was augmented by likelihood ratios (LR)of 8.25 (LR +) for results with <4% normal morphology and0.15 (LR-) for results with 12% normal morphology by strictcriteria. While there was some correlation between strict criteriaand standard assessment of morphology (r²=0.35), the formerexplained only 12% (r²=0.12) of the variability in the latter.This study concludes that strict criteria morphology predictsfertilization, while other semen parameters do not. A 12% cut-offpoint makes strict criteria morphology an excellent predictorof satisfactory fertilization, while a value <4% is a goodpredictor of poor fertilization.     

Sperm morphological assessment based on strict criteria and in-vitro fertilization outcome.

One-hundred-and-twenty-three in-vitro fertilization (IVF) cycles were analysed in order to clarify the influence of strictly normal morphology (SNM) of spermatozoa on IVF outcome. SNM was defined using strict criteria according to Kruger with our modifications. The IVF cycles studied were divided into three groups: %SNM less than 12% (13 cycles), 12 less than 40% (68 cycles), greater than or equal to 40% (42 cycles). The cleavage rates per oocyte were higher in the groups with 12-40% and greater than or equal to 40% of %SNM than in the group with %SNM less than 12%. The embryo transfer rate per cycle increased with increasing %SNM. The overall pregnancy rate per cycle increased with increasing %SNM (7.7% in %SNM less than 12%, 22.1% in 12-40% of %SNM, and 40.5% in %SNM greater than or equal to 40%). The ongoing pregnancy rate per cycle also increased with increasing %SNM (7.7% in %SNM less than 12%, 14.7% in 12-40% of %SNM, and 31.0% in %SNM greater than or equal to 40%). The miscarriage rate was lower in %SNM greater than or equal to 40% (23.5%) than in 12-40% of %SNM (33.3%). It was suggested that %SNM is a good predictor of IVF outcome.     

Quality control in an in-vitro fertilization laboratory: use of human sperm survival studies

A bioassay procedure is described for quality control testingof various disposable items used in routine IVF procedures.This biosassay is performed over 4 days and uses the survivalof human sperm in vitro at room temperature to assess whichproducts are suitable for use. New products were tested forcytotoxicity using a general screening method and subsequenthatches of every suitable item tested to detect interbatch variation.Products were considered suitable or unsuitable for use dependingupon a calculated sperm survival index. Two main types of productwere found to be cytotoxic, namely certain brands of syringeand surgical gloves, the common feature of both being the presenceof rubber components. The bioassay was also used to investigatefurther the cytotoxic effect of the powdered and starch-freesurgical gloves. The cytotoxic substances from both types ofsurgical glove were readily transferred to an embryo replacementcatheter by touch, and washing of the gloves reduced this effectonly moderately. The bioassay has proved inexpensive and convenientbut more importantly it has been invaluable for detecting potentialsources of cytotoxicity before they are introduced into a standardIVF protocol.     

Andrology: Nuclear decondensation of sperm head and failure at in-vitro fertilization: an ultrastructural study

The problem of unexplained male infertility was investigatedby electron microscopic study of spermatozoa from 51 males.The subjects were subdivided as follows: group A (n = 25) normalfertile males (controls), group B (n = 13) successful in-vitrofertilization (IVF) cases (fertilization rate >50%), groupC (n = 13) failed IVF cases. All subjects included in groupsB and C had a 6–12 year history of childlessness and IVFwas employed when other methods of assisted reproduction failed.The study of spermatozoa in fertile males (controls) was carriedout to establish baseline ultrastructural abnormalities. Inall 51 cases, an average of 330 (280–800) sperm headsand 660 (330–1190) sperm tails were studied. Decondensationof nuclear chromatin was observed in 70 ± 15% (mean ±SD) of spermatozoa in failed IVF cases, 16 ± 5% in successfulIVF cases and 7 ± 3% in controls. These results werefound to be statistically significant (P > 0.001). The meanvalue for motility of spermatozoa in all three groups was withinaccepted limits of normality. It is concluded that decondensationof nuclear chromatin seen by electron microscopy is one of themost important causes of male infertility. It is advocated thatelectron microscopic examination of semen should be carriedout in all cases of longstanding, unexplained male infertilitybefore embarking upon IVF programmes.     

Evaluation of variations in pregnancy rates, implantation rates and early abortion rates within an in-vitro fertilization programme

Despite the application at this clinic of a standardized programmefor in-vitro fertilization of human oocytes over the last 27months, great variations in the rates of implantation, clinicalpregnancy and early abortion have been observed during certainperiods. A retrospective evaluation of these results showedthat these variations occurred in periods when various commerciallyavailable batches of Earle‘s medium (the medium was theonly variable changed during the 27 months) were used and thattwo sub-optimal batches of Earle’s medium from one ofthe sources used during one of three periods (period 2) wasmost likely to be responsible for sub-optimal embryo qualityand, consequently, for a halving of the pregnancy rate (30 versus15%) and of the implantation rate (11 versus 5%) and an increasein the early abortion rate (23 versus 50%), It is concludedthat the quality of the culture medium is of major importancefor the success of an IVF programme. The factor(s) in the mediumresponsible for the decrease in embryo quality has not beenidentified.     

Hydrosalpinx reduces in-vitro fertilization/embryo transfer pregnancy rates

A retrospective study was designed to examine whether the presenceof a hydrosalpinx influenced pregnancy outcome following in-vitrofertilization (IVF) treatment In stimulated cycles. A totalof 254 women with tubal lesions were included. Patients withone or two hydrosalpinges were compared with patients havingother tubal lesions and pregnancy outcome was analysed. Bothpregnancy and delivery rates were significantly higher in thepatient group without a hydrosalplnx. The results after frozenembryo transfer showed the same tendency. These findings stronglyindicate that a permanent hydrosalpinx has a negative influenceon implantation, as well as on pregnancy, and suggest that amore active approach against large hydrosalpinges should beundertaken before I.VF treatment, in order to improve the pregnancyrates.     

Human and bovine cervical mucus penetration as a test of sperm function for in-vitro fertilization

Human and bovine cervical mucus penetration tests (n = 57) wereperformed preceding IVF to test their prognostic value as spermfunction tests for IVF. This evaluation also induded resultsfrom conventional semen analysis and from a computerized spermanalysis system. The bovine cervical mucus penetration testwas shown to be at least as valuable as the human cervical mucuspenetration test in evaluating sperm function. The migrationdistance of the vanguard sperm (P < 0.001) and the spermdensity at a fixed migration distance in the mucus column (P< 0.05) correlated most closely with the IVF results. A clearparallelism with the out come of the ‘swim up’ techniquewas also found. Of the sperm parameters examined, only spermmotility In the ejaculate (P < 0.05) correlated significantlywith the results of IVF. It is concluded that the outcome ofa bovine cervical mucus penetration test depends on the samesperm functions as re quired for IVF. Therefore, this test maybe of predictive value in an IVF programme.     

Full-term pregnancies achieved with ICSI despite high levels of sperm chromatin damage

BACKGROUND: Sperm DNA integrity is essential for the accurate transmission of genetic information. The clinical significance of this assessment lies in its association with not only natural conception rates, but also the success of assisted reproduction technology (ART). It has been reported that sperm chromatin structure assay (SCSA) identified thresholds for negative pregnancy outcome after ART when the DNA fragmentation index (DFI), previously known as COMPalphat, was >30%. METHODS: In a prospective clinical study, we examined 34 male infertile patients, the husbands of women undergoing conventional IVF or ICSI. SCSA and ART were carried out on semen aliquots taken from the same ejaculate. Fertilization rate, embryo quality and pregnancy rates were correlated to SCSA parameters, DFI and highly DNA stainable (HDS) cells. RESULTS: No differences were seen in SCSA parameter values between patients initiating pregnancies and not doing so in either ICSI or conventional IVF. Pregnancies and normal delivery were obtained even with high levels of DFI. CONCLUSIONS: There is still controversy over whether analytical techniques currently in use are able to identify the level of damage to spermatozoa. Large-scale studies should be conducted in different clinical settings to determine the effects of sperm DNA damage on the outcome of ART.     

Sperm chromatin anomalies can influence decondensation after intracytoplasmic sperm injection

In this study we investigated whether morphology and chromatinanomalies in human spermatozoa can influence fertilization afterintracytoplasmic sperm injection (ICSI). We examined unfertilizedoocytes, using the fluorochrome Hoechst 33342, to determinewhether a relationship exists between failure of fertilizationand sperm chromatin quality. Sperm chromatin packaging qualitywas assessed using the chromomydn A3 (CMA3) fluorochrome, andthe presence of DNA damage in spermatozoa, using in-situ nicktranslation. Normal males present sperm parameters with a normalmorphology of >20%, CMA3 fluorescence of <30% and exhibitendogenous nicks in <10% of their spermatozoa. When patientswere separated according to these values no difference was observedin their fertilization rates after ICSL When the unfertilizedICSI oocytes were examined, we found that patients with CMA3fluorescence of <30% and nicks in <10% of their spermatozoahad only 17.5 and 21.6% respectively of their unfertilized oocytescontaining spermatozoa that remained condensed. In contrast,patients with higher CMA3 and nick values had a significantlyhigher number, 412 and 48.9%, of their unfertilized oocytescontaining condensed spermatozoa. Sperm morphology did not showany such pattern. The percentage of spermatozoa which had initiateddecondensation in unfertilized oocytes was not influenced bymorphology, CMA3 fluorescence or nicks. In light of these resultswe postulate that poor chromatin packaging and/or damaged DNAmay contribute to failure of sperm decondensation after ICSIand result in failure of fertilization.     

Follicle-stimulating hormone as a prognostic indicator in clomiphene citrate/human menopausal gonadotrophin-stimulated cycles for in-vitro fertilization

Follicle-stimulating hormone (FSH), luteinizing hormone (LH), oestradiol and prolactin levels were studied in a sequential clomiphene citrate/human menopausal gonadotrophin (CC/HMG) regimen for in-vitro fertilization. At completion of CC administration, the median FSH level in 44 cancelled cycles was elevated compared to a control group of 65 completed cycles, 29 IU/l versus 15 IU/l, P less than 0.01. Also the median FSH/LH ratio was higher in the cancelled cycles than in the control group, 1.08 versus 0.71, P less than 0.05. Conversely, the median oestradiol level was lower in the cancelled cycles than in the completed cycles, 0.27 nmol/l versus 0.59 nmol/l, P less than 0.01. No difference was seen in the median LH and prolactin levels. An FSH value above the 95% confidence limit was found in 24 of the cancelled cycles, but in only two of the completed cycles. Based on this study, an elevated FSH value following CC administration predicts a poor response to further stimulation with an accuracy of 92.3% and should result in cancellation of the cycle.     

Sperm chromatin structure assay parameters as predictors of failed pregnancy following assisted reproductive techniques

The predictive value of sperm chromatin integrity for pregnancy outcome following in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) was studied in 24 men attending a university-based assisted reproductive techniques laboratory using the flow cytometric sperm chromatin structure assay (SCSA). The SCSA is a measure of the susceptibility of sperm DNA to low pH-induced denaturation in situ. The mean percentage of spermatozoa in the neat sample demonstrating DNA denaturation was significantly lower in the seven men that initiated a pregnancy (15.4 +/- 4.6, P = 0.01) than in the 14 men who did not initiate a pregnancy (31.1 +/- 3.2). No pregnancies resulted if > or =27% of the spermatozoa in the neat semen sample showed DNA denaturation. These data demonstrate that SCSA parameters are independent of conventional semen parameters. Furthermore, the SCSA may allow physicians to identify male patients for whom IVF and ICSI will be unlikely to result in pregnancy initiation.     

Successful fertilization and pregnancy outcome in in-vitro fertilization using cryopreserved/thawed spermatozoa from patients with malignant diseases.

Cryopreservation of spermatozoa before treatment is the only proven effective method available to circumvent the sterilizing effect of therapy in some patients with malignant diseases. Because of impaired sperm quality after freezing and thawing in-vitro fertilization/embryo transfer (IVF/ET) was indicated in 10 patients (12 cycles) during 1986-1990. The patient's mean age was 33.4 +/- 1.6 years. The following diagnoses were made: seminoma (1), testicular carcinoma (3), leiomyosarcoma of the prostate (1), Wegener's granulomatosis (1), non-Hodgkin's (1) and Hodgkin's lymphoma (3). When motile spermatozoa could be recovered after thawing, the total fraction of motile spermatozoa after swim-up separation ranged from 0.2 to 4.2 x 10(6) spermatozoa/ml (eight patients, nine cycles). In all these cases, insemination was performed with multiple oocytes per dish. Fertilization was achieved when swim-up recovered a mean of 1.8 +/- 0.5 x 10(6) spermatozoa/ml and when insemination was performed with at least a calculated concentration of motile spermatozoa of 1 x 10(5) spermatozoa/oocyte. The fertilization rate of preovulatory oocytes was 60%. Four patients achieved a pregnancy: two of them delivered a single healthy baby, one delivered triplet healthy babies and one had a preclinical abortion. In two patients (three cycles), no motile spermatozoa were recovered after thawing, and micromanipulation of oocytes for assisted fertilization was performed. Although fertilized oocytes were transferred, those couples did not achieve a pregnancy. Patients with lymphopathies had the best results, whilst those with testicular neoplasms had the poorest outcome, thus suggesting a poor gametogenic function in the non-affected testis. These results give hope to some patients with malignant diseases to maintain their reproductive capacity through sperm banking and IVF/ET.     

Comparative auto-controlled study between swim-up and Percoll preparation of fresh semen samples for in-vitro fertilization.

This study compared swim-up and Percoll preparation of fresh semen samples for in-vitro fertilization. Sixty trials of in-vitro fertilization (IVF), 38 with normal semen and 22 with abnormal semen, comprising 734 oocytes were included in the study. Each semen sample was prepared by both a swim-up technique and a simplified discontinuous (50%, 70%, 90%) Percoll gradient. The oocytes for each trial were distributed at random between the two sperm preparations and incubated with the same number of motile spermatozoa. Percoll gradient preparation produced a significantly higher final concentration of spermatozoa than swim-up preparation (mean +/- SEM: 6.6 +/- 1.5 x 10(6)/ml versus 1.9 +/- 0.2 x 10(6)/ml; P less than 0.01) but a significantly lower sperm motility (69 +/- 2% versus 94 +/- 1%; P less than 0.001) and a lower number of normal forms (55 +/- 2% versus 64 +/- 2%; P less than 0.01). The ability of the Percoll gradient method to extract motile spermatozoa was higher than that of the swim-up technique (20 +/- 15.6% versus 0.8 +/- 13.6%). Nevertheless, the rates of fertilization (61%), fertilization failure (18%) and polyspermia (9%), embryo quality evaluated by mean embryo scores (3.8 +/- 0.3) and the mean number of spare embryos frozen per trial (1.4 +/- 0.3) were strictly identical in both groups. The 24 pregnancies (including three from frozen--thawed embryos) obtained in these 60 trials (40% per oocyte retrieval) could not be separated according to the sperm preparation method, as embryos from both groups were replaced together.(ABSTRACT TRUNCATED AT 250 WORDS)     

Andrology: The effect of chromatin condensation (Aniline Blue staining) and morphology (strict criteria) of human spermatozoa on fertilization, cleavage and pregnancy rates in an intracytoplasmic sperm injection programme

The main purpose of this study was to determine the possiblerelationship between chromatin condensation (Aniline Blue staining),the morphology of spermatozoa according to strict criteria,and the fertilization, cleavage and pregnancy rate in an intracytoplasmicsperm injection (ICSI) programme. A total of 60 patients weredivided into two groups (27 versus 34) according to sperm stainabilityby Aniline Blue. The first group involved patients having apositive Aniline Blue staining test with 0–29% stained.The fertilization rate in this group was 60.8%, cleavage rate54.4% and pregnancy rate 18.5%. In the second group in which>29% spermatozoa were positively stained, the fertilizationrate was 62.1%, cleavage rate 62.0% and pregnancy rate 353%.There was no statistically significant difference between thetwo groups. Furthermore, the influence of morphology accordingto strict criteria after Papanicolaou staining on successfulfertilization, cleavage and pregnancy was studied in 85 patientswho were divided into two groups according to the percentageof morphologically normal sperm. The fertilization, cleavageand pregnancy rates were 44.21, 6337, and 39.47% respectivelyin the first group (<4%), the corresponding values for thesecond group (>4%) were 56.50, 46.04 and 21.21%. There wasno significant correlation between the fertilization (P = 0.722),cleavage (P = 0.519) and pregnancy (P = 0.096) rates in eithergroup. This stndy demonstrates that neither chromatin condensation(Aniline Blue staining) nor morphology could assess the fertilizationpotential, cleavage and pregnancy rate in an ICSI programme.     

The use of silane-coated silica particles for density gradient centrifugation in in-vitro fertilization

Silane-coated silica particles (PureSperm) were evaluated as an alternative to Percoll for gradient separation of spermatozoa, for use in assisted reproduction. Recovery of motile and morphologically normal spermatozoa after using a four-layer Percoll and a two- and four-layer PureSperm gradient respectively was recorded. In-vitro fertilization (IVF) results after using PureSperm for the sperm preparation were also evaluated. No difference in sperm recovery or sperm motility was found when comparing the use of Percoll and the four-layer gradient of PureSperm. When using a two-layer PureSperm gradient, motility was significantly decreased (P < 0.05) compared to Percoll. Normal sperm morphology increased from 8-17.2% after using Percoll and to 12.7% and 11.4% after using a four-layer and a two-layer PureSperm gradient respectively. All gradient preparations showed a significant decrease in the teratozoospermia index compared to the ejaculate (P < 0.01). No significant differences in IVF results regarding fertilization and pregnancy rates were found when PureSperm or the swim-up technique were used for the sperm preparation. PureSperm seems to be an acceptable alternative to Percoll but although the percentage of sperm recovery was higher after PureSperm we still recommend the swim-up technique to be the first choice, as a higher percentage of progressive motile spermatozoa is obtained without using other chemicals than IVF culture medium.     

Teratozoospermia and in-vitro fertilization: a randomized prospective study

A prospective randomized study was conducted to assess the prognosticvalue of sperm morphology in an in-vitro fertilization (IVF)programme, using strict criteria. The first group (T, teratozoospermic)included 32 couples with an isolated teratozoospermia in themale partner (morphology <9% normal). The second group (C,control) contained 36 couples with normal semen parameters,including morphology (>9% normal, strict criteria). In bothgroups, 50 IVF cycles were performed. Patients were matchedfor indication for IVF. There was no difference between thetwo groups regarding age, duration of infertility, stimulationprotocol, catheter used for embryo transfer and different spermparameters. A statistically significant difference between theT and C groups respectively was observed regarding the fertilizationrate (69.2 and 79.4%P < 0.05), pregnancy rate per cycle (12.0and 42%, P < 0.001), the pregnancy rate per transfer (13.9and 42.0%, P< 0.01) and per embryo transferred (6.1 and 14.8%,P< 0.05). No pregnancy occurred in the poor prognosis group(morphology <5% normal). In cases of moderate teratozoospermia,the fertilization rate appeared normal (78.6%) but the conceptionrate remained low. We concluded that the use of strict criteriain the assessment of sperm morphology is useful in predictingfertilization and pregnancy rate in the human in-vitro model.     

Epididymal sperm aspiration in conjunction with in-vitro fertilization and embryo transfer in cases of obstructive azoospermia.

Epididymal sperm aspiration is a new treatment for vasal agenesis. In previous reports, epididymal spermatozoa resulted in pregnancy by utilizing in-vitro fertilization (IVF) or gamete intra-Fallopian transfer (GIFT). We sought to investigate the efficacy of epididymal sperm aspiration in conjunction with IVF in patients with congenital absence of the vas deferens or with secondary extended obstruction of spermatic ducts. Fifty-eight attempts were performed in 23 patients (25-50 years). Eight patients (34.7%) had vasal agenesis and 14 (60.8%) presented with vasal secondary extended obstruction. The sperm count was adequate (greater than or equal 20 x 10(6)/ml) in 13.8% of sperm retrievals and sperm motility of 20% was obtained in 15.5% of sperm retrievals. Fourteen attempts at IVF were performed with epididymal sperm counts of 2-44 x 10(6)/ml and motilities of 0-45%. A mean of six mature oocytes (0-13) were inseminated in each case. Five embryo transfers were performed in five patients' wives (35.7%) and two couples had an early pregnancy loss (14.2%). Epididymal sperm aspiration is an advance in treating such patients, as an adequate number of mature spermatozoa can be obtained and used for IVF. However, spermatozoa directly aspirated from the proximal epididymis and with fertilizing capacity in vitro, gave a high rate of embryo degeneration (greater than 50%) after embryo transfer.     

Embryo transfer under ultrasound guidance improves pregnancy rates after in-vitro fertilization

Between October 1998 and January 1999, we examined the influence of ultrasound guidance in embryo transfer on pregnancy rate in 362 patients from our in-vitro fertilization (IVF)-embryo transfer programme. These patients were prospectively randomized into two groups: 182 had ultrasound-guided embryo replacement, and 180 had clinical touch embryo transfer. There were no statistically significant differences between the two groups with respect to age, cause of infertility and in the characteristics of the IVF cycle. The pregnancy rate was significantly higher among the ultrasound-guided embryo transfer group (50%) compared with the clinical touch group (33.7%) (P < 0.002). Furthermore, there was also a significant increase in the implantation rate: 25.3% in the ultrasound group compared with 18.1% in the clinical touch group (P < 0.05). In conclusion, ultrasound assistance in embryo transfer significantly improved pregnancy and implantation rates in IVF.