Influence of position and length of uterus on implantation and clinical pregnancy rates in IVF and embryo transfer treatment cycles

Three-Dimensional Measurement of the Uterus on Magnetic Resonance Images: Development and Performance Analysis of an Automated Deep-Learning Tool

Uterus measurements are useful for assessing both the treatment and follow-ups of gynaecological patients. The aim of our study was to develop a deep learning (DL) tool for fully automated measurement of the three-dimensional size of the uterus on magnetic resonance imaging (MRI). In this single-centre retrospective study, 900 cases were included to train, validate, and test a VGG-16/VGG-11 convolutional neural network (CNN). The ground truth was manual measurement. The performance of the model was evaluated using the objective key point similarity (OKS), the mean difference in millimetres, and coefficient of determination R2. The OKS of our model was 0.92 (validation) and 0.96 (test). The average deviation and R2 coefficient between the AI measurements and the manual ones were, respectively, 3.9 mm and 0.93 for two-point length, 3.7 mm and 0.94 for three-point length, 2.6 mm and 0.93 for width, 4.2 mm and 0.75 for thickness. The inter-radiologist variability was 1.4 mm. A three-dimensional automated measurement was obtained in 1.6 s. In conclusion, our model was able to locate the uterus on MRIs and place measurement points on it to obtain its three-dimensional measurement with a very good correlation compared to manual measurements.

Inspection depth of uterine lumen measured by transvaginal ultrasound is associated with the success of IVF: a prospective longitudinal cohort study in China

OBJECTIVE

To measure the inspection depth of uterine lumen by transvaginal ultrasound and assess the association between the inspection depth and pregnancy outcomes in IVF-ET.

METHODS

This prospective longitudinal cohort study was conducted from June 2018 to December 2020. We enrolled patients aged 20-45 years who underwent frozen embryo transfer cycle. We calculated the average distance from the uterine lumen to the ultrasound probe (inspection depth) using transvaginal ultrasonography and divided the entire cohort into four groups according to the quartiles of the overall inspection depth distribution. The chi-square test was used to compare the pregnancy outcomes of the four groups. Univariate and multivariate regression analyses were performed to assess the association between the inspection depth and pregnancy outcomes.

RESULTS

Seven hundred forty-two patients were finally enrolled, and they were grouped according to the inspection depth quartiles. There were significant decrease in the clinical pregnancy, implantation, and live birth rates among the four groups (P < 0.05); however, there was no significant difference in the miscarriage rate. Multivariable logistic regression analysis with the inspection depth as a continuous variable demonstrated that the inspection depth was associated with clinical pregnancy, implantation, and live birth rates (clinical pregnancy rate, adjusted odds ratio, 0.549; 95% confidence interval, 0.380-0.793; implantation rate, adjusted odds ratio, 0.680; 95% confidence interval, 0.496-0.931; live birth rate, adjusted odds ratio, 0.602; 95% confidence interval, 0.420-0.863), but not with the miscarriage rate.

CONCLUSIONS

The inspection depth of the uterine lumen measured by transvaginal ultrasound was associated with IVF success.

TRIAL REGISTRATION

This prospective observational study was registered at the Chinese Clinical Trial Registry ( www.chictr.org.cn ) (ChiCTR2200057977) on March 24, 2022, retrospectively registered.

The position of the euploid blastocyst in the uterine cavity influences implantation

RESEARCH QUESTION

Does the position of the euploid blastocyst in the uterine cavity upon transfer, measured as distance in millimetres (mm) from the fundus (DFF) to the air bubble, influence implantation potential?

DESIGN

A total of 507 single/double euploid frozen embryo transfer (FET) cycles at blastocyst stage were included retrospectively between March 2017 and November 2018 at a single centre. The patients were on average 33.3 years old. The FET were performed in natural cycles (n = 151) or hormone replacement therapy cycles (n = 356).

RESULTS

Of the 507 transfers, 370 (73.0%) resulted in a pregnancy, defined as human chorionic gonadotrophin concentration over 15 mIU/ml, and 341 (67.3%) in a clinical pregnancy, with an implantation rate of 62.0% and ongoing pregnancy rate of 59.6% (302/507). When comparing the number of embryos transferred, the pregnancy rate, clinical pregnancy rate and ongoing pregnancy rate were significantly higher after double-embryo transfer (DET) (P = 0.002: P < 0.001 and P = 0.002). The quality of the blastocyst in the single-embryo transfer group had a positive effect on the pregnancy rate (A versus B, P = 0.016; A versus C, P = 0.003) and clinical pregnancy rate (A versus C, P = 0.013). After performing a multivariate logistic regression analysis to consider the effect of all explanatory variables, a negative effect between DFF and pregnancy (P = 0.001), clinical pregnancy (P = 0.001) and ongoing pregnancy (P = 0.030) was found. When all variables remained constant, an increase of 1 mm of DFF changed the odds of pregnancy by 0.882, of clinical pregnancy by 0.891 and of ongoing pregnancy by 0.925. No significant effect of DFF was found on the miscarriage outcome (P = 0.089).

CONCLUSIONS

The depth of blastocyst replacement inside the uterine cavity may influence the pregnancy, clinical pregnancy and ongoing pregnancy rates and should be considered as an important factor to improve the success of IVF cycles.

Effect of embryo transfer depth on IVF/ICSI outcomes: A randomized clinical trial

Background

Although there has been remarkable advancement in the field of assisted reproductive technology, implantation failure remains a significant issue in most infertile couples receiving these treatments. Embryo transfer is important in assisted reproductive technology and directly affects the implantation rates and pregnancy outcomes.

Objective

To assess the effect of two different distance embryo transfer sites from fundal endometrial surface on the outcomes of in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles.

Materials and Methods

A total of 180 women who were candidate for IVF/ ICSI/ embryo transfer in Yazd Research and Clinical Center for Infertility were equally assigned to two groups based on the distance between the fundal endometrial surface and catheter tip to investigate implantation, chemical and clinical pregnancy (group A: 15 ± 5 mm and group B: 25 ± 5 mm, respectively).

Results

The subjects in the group B showed significantly higher implantation rate, chemical and clinical pregnancy rate compared to the group A (p = 0.03, 0.01, 0.04, respectively). The rate of ongoing pregnancy and miscarriage indicated no significant differences between groups (p = 0.21, 0.27, respectively).

Conclusion

In conclusion, our study showed that the depth of embryo replacement inside the uterine cavity at a distance of 25 ± 5 mm beneath fundal endometrial surface have better effects on the pregnancy outcomes of IVF/ICSI cycles and can be considered as an important factor to improve the success of IVF cycles.

Effect of uterine dimensions on live birth rates after single embryo transfer in infertile women

RESEARCH QUESTION

Do uterine size parameters measured by baseline transvaginal ultrasound predict live birth after single embryo transfer (SET) of a high-quality blastocyst?

DESIGN

Retrospective cohort study including women undergoing their first SET between August 2010 and March 2014 at a large university hospital reproductive centre. The effects of baseline uterine dimensions on live birth rate (LBR) were analysed while controlling for confounding effects.

RESULTS

A total of 437 nulliparous and 70 parous women were included. The nulliparous group had lower body mass index (BMI) (24.4 ± 5.1 versus 25.9 ± 4.5 kg/m²; P = 0.015) and a higher number of fibroids (0.4 ± 1.0 versus 0.2 ± 0.5; P = 0.005) than the parous group. While controlling for confounding effects, none of the uterine parameters appeared to be a significant predictor of LBR among nulliparous and parous women (P > 0.05 in all cases). A subsequent analysis of endometrial length was done, whereby the endometrial lengths were divided into quartiles (20.0-32.2 mm; 32.3-36.5 mm; 36.6-40.0 mm; 40.1-54.0 mm). After controlling for confounders, the shortest quartile in the nulliparous group had a significantly lower LBR (P = 0.02) than the other groups. Receiver operating characteristic curves suggested that endometrial cavity length and cervical length did not aid clinically.

CONCLUSION

Uterine parameters do not have a clinically useful impact on LBR after SET of a blastocyst in infertile women. The use of baseline endometrial length to predict live birth is no better than chance, while cervical length only predicts failure to live birth.

Analysis of the reproductive outcomes and the size of the unicornuate uterus measured by magnetic resonance imaging and their relationship

PURPOSE

To evaluate the relationship between the uterine size measured by pelvic magnetic resonance and reproductive outcome in women with a unicornuate uterus.

METHODS

This was a retrospective study including 140 patients affiliated with unicornuate uterus diagnosed by the pelvic MR prior to their first pregnancy in the Obstetrics and Gynecology Hospital of Fudan University from April 2010 to December 2017. All the length of the unicornuate uterus were re-measured and recorded by skilled radiologists during the study period. We divided all the 140 participants with complete pelvic MR imaging into four groups by the best reproductive outcomes, which refers to Group 1 (primary infertility, n = 21), Group 2 ( < 24 weeks' gestation, n = 34), Group 3 (preterm delivery, 24-35 weeks' gestation, n = 13), Group 4 ( ≥ 35 weeks' gestation, n = 72), followed them up and then analyzed the data.

RESULTS

Measurements of 140 patients with hemi-uteri were retrieved for analysis. The mean length of the uterine was 4.90  ± 0.56 cm. There were no significant differences in the uterine cavity length, cervical length, endometrial thickness and uterine wall thickness between the four groups while the uterine length (P = 0.001) was statistically significant. Women with uterine lengths  ≥  4.5 cm were more likely to experience full-term delivery compared with the other group (P = 0.001). Ordinal multiple logistic regression analysis showed that the uterine length [OR = 9.03 (95% CI: 2.90-28.13)] and uterine cavity length [OR = 0.32 (95% CI: 0.06-2.04)] were independent protective factors for better obstetric outcomes CONCLUSION: The uterine length is a reliable prognostic factor for the gestational week of delivery and an appropriate antenatal surveillance factor of women with unicornuate uterus.

Uterine size and volume are associated with a higher clinical pregnancy rate in patients undergoing assisted reproduction technology: A longitudinal study (A STROBE-compliant article)

The aim of this study was to investigate the relationships between uterine size and volume and clinical pregnancy rate.This longitudinal study was conducted among patients undergoing assisted reproduction technology (ART) treatment at the Reproductive Medicine Center from January 2010 to May 2017, all of whom provided informed consent to participate in the study. The uterine size, for all patients, was measured by transvaginal ultrasonography before ovarian stimulation. Clinical pregnancy was diagnosed by ultrasound confirmation of at least an intrauterine gestational sac and fetal cardiac activity 4 weeks after embryo transfer.A total of 11,924 patients were enrolled in this study. Compared to patients with uterine lengths of 50 to 59 mm (referent), patients with uterine lengths ≥60 mm had a lower clinical pregnancy rate. Compared to patients with uterine widths of 30 to 39 mm (referent), patients with uterine widths of 40 to 49 mm and those with uterine widths of ≥50 mm had a lower clinical pregnancy rate. Compared with those with a uterine anteroposterior diameter of <30 mm (referent), patients with uterine anteroposterior diameters of ≥50 mm had a lower clinical pregnancy rate. Compared with those with a uterine volume of 30 to 49 mL (referent), patients with a uterine volume ≥70 mL had a lower clinical pregnancy rate.The patients with an optimal uterine length, width, anteroposterior diameter, and volume had a higher clinical pregnancy rate than those with suboptimal uterine measurements. Uterine sizes and volumes that were too large reduced the clinical pregnancy rate.

Pelvic Floor Support Defect in Apical Anterior Vaginal Prolapse with Cervical Hypertrophy. Review with Case Report in a 20-year-old Cadaver

Apical anterior vaginal wall prolapse (AVWP) with central defect is uncommon in young non hysterectomized patients causing considerable mortality after the fourth decade of life. Its high propensity to recurrence poses the greatest challenge to pelvic reconstructive surgeons. Approximately 40% of women with prolapse have hypertrophic cervical elongation and the extent of elongation increases with greater degrees of prolapse. Women with prolapse either have inherent hypertrophic elongation of the cervix which predisposes them to prolapse or the downward traction in prolapse leads to cervical elongation. The Pelvic Organ Prolapse Quantification (POP-Q) examination includes measurement of the location of the posterior fornix (point D) with the assumption that this measurement is associated with cervical elongation. Multifocal site involvement with apical and perineal descent primarily afflicts elderly, postmenopausal women after the fourth decade while cervical hypertrophic elongation with prolapse is observed in younger women less than 40 years of age. A review of the anatomical implication of the association of cervical hypertrophy in prolapse is carried out in this article. We observed a combination of distension type anterior vaginal prolapse with apical descent and cervical hypertrophy in a 20-year-old cadaver during routine dissection for undergraduate medical students at Sikkim Manipal Institute of Medical Sciences in 2013. Distension type anterior vaginal prolapse with central defect is rarer as most reported cases are of the displacement type, paravaginal defect. Hypertrophic cervical elongation is either the cause or consequence of prolapse and its identification before reconstructive surgery is paramount as uterine suspension in the face of cervical elongation is contraindicated. Inappropriate identification of all support defects and breaking of tissues is the primary cause of failure of laparoscopic pelvic reconstructive surgery.

Predictive value of the time interval between embryo loading and transfer for IVF/ICSI success: a prospective cohort study

BACKGROUND

The influence of embryo loading time (ELT) and the time interval between embryo loading and embryo transfer (TIEL-ET) on the success of IVF/ICSI is unknown.

METHODS

In a prospective cohort study, we aimed to ascertain the influence of ELT and TIEL-ET on ongoing pregnancy rate (OPR) and life birth rate (LBR). Data from 603 consecutive embryo transfers between January 2008 and December 2013 were collected. A complete data set including the outcomes of interest OPR and LBR was available for 410 women. The primary outcome was IVF/ICSI success, defined as OPR and LBR.

RESULTS

We used univariate and multivariate logistic regression for analysis. In a multivariate analysis, age (odds ratio [OR] 0.94; 95% confidence interval [CI] 0.89-0.99), catheter type (OR 0.45; 95% CI 0.24-0.84), and uterine length (OR 1.03; 95% CI 1.01-1.06), but not ELT and TIELT-ET were independently associated with OPR. Regarding LBR, age (OR 0.93; 95% CI 0.88-0.98), catheter type (OR 0.41; 95% CI 0.22-0.79), and uterine length (OR 1.03; 95% CI 1.01-1.06), but not ELT and TIELT-ET were independent predictors.

CONCLUSION

We conclude that speed of embryo transfer is not critical for the success of IVF/ICSI. However, care should be taken to choose catheter types proven to be associated with a high success rate.

Individualized embryo transfer training: timing and performance

STUDY QUESTION

How long is the individualized training and the stability of competence for the embryo transfer (ET) technique?

SUMMARY ANSWER

The embryo transfer technique is easy-to-learn, hardly unlearned, and training should be individualized by monitoring with learning curve-cumulative summation (LC-CUSUM) curves.

WHAT IS KNOWN ALREADY

Like many medical procedures, embryo transfer is an operator-dependent technique. Individualized or standardized training of these medical procedures should be monitored to determine when competence is acquired.

STUDY DESIGN, SIZE, DURATION

This prospective, monocentric study involving five embryo transfer trainees was carried out between August 2011 and November 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was carried out in a large private clinic. Five gynaecologist trainees during their first year of assisted reproduction subspecialty performed embryo transfer for patients undergoing either fresh IVF, oocyte donor IVF, or frozen embryo transfer. There were 586 embryo transfers performed in 96 sessions of 3-10 embryo transfers each. An embryo transfer was considered successful if it gave rise to a positive pregnancy test 14 days later. LC-CUSUM and cumulative summation (CUSUM) curves were used to determine when competence was acquired and whether it was maintained over time, respectively. The length of time between two consecutive sessions was assessed for an effect on consolidation of the acquired competence.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed that all five trainees became proficient in embryo transfer by procedure 15 (after procedure 15, 9, 7, 13 and 9, respectively). Once competence was achieved, one of the five trainees showed a loss of proficiency. After having acquired competence, the median pregnancy rate per embryo transfer session was significantly lower when the interval between consecutive embryo transfer sessions was ≥10 days compared with <10 days (20.0 versus 46.7%; P = 0.006).

LIMITATIONS, REASONS FOR CAUTION

The patient groups included in the study were heterogeneous (IVF, oocyte donor IVF and frozen embryo transfer) and their outcomes are very variable; thus the distribution and proportion of these groups can determine the timing of competence acquisition. Our data show that low numbers of embryo transfer are needed to acquire competence, but since a relative high percentage of embryo transfers in our practice are from oocyte donor IVF, extrapolation of the findings to other clinical context should be done with caution.

WIDER IMPLICATIONS OF THE FINDINGS

Personalized embryo transfer training is feasible and useful, allowing clinics, on one hand, to offer a maximum chances of pregnancy with fully trained personnel, and the other hand, to avoid the superfluous and costly overtraining of already proficient trainees. Furthermore, it is advisable to maintain a short interval of time between consecutive embryo transfer sessions after a trainee has acquired competence, to avoid a significant drop in the resulting pregnancy rate.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by funding from Fundació Privada EUGIN. There are no conflicts of interest to declare.

Hysteroscopy in patients with repeated implantation failure improves the outcome of assisted reproductive technology in fresh and frozen cycles

AIM

Repeated implantation failure (RIF) is still a problem for many patients and their physicians. Some interventions have been practiced to overcome the problem; one is uterine cavity assessment before assisted reproductive technology (ART) cycles. This study aimed to evaluate the effect of hysteroscopy in women experiencing recurrent implantation failure with apparently normal uterine cavity before assisted reproductive techniques.

MATERIAL AND METHODS

This was a cohort study with historical controls conducted in a university hospital. A total of 353 women with RIF undergoing ART with normal hysterosalpingography and transvaginal ultrasound were evaluated. The intervention group underwent hysteroscopy with a rigid, 30°, 4-mm hysteroscope in the menstrual cycle just before ART; in the control group hysteroscopy was not performed. Basal characteristics, stimulation parameters and pregnancy rates were compared between the two groups.

RESULTS

Chemical pregnancy occurred in 58.5% of women in the hysteroscopy group versus 34.1% of control women (odds ratio [OR]: 2.7; 95% confidence interval [CI]: 1.7-4.2; P < 0.001). Clinical pregnancy occurred in 50.7% and 30.3% of women in the hysteroscopy and control groups, respectively (OR: 2.4; 95%CI: 1.5-3.7; P < 0.001). Delivery rate was 35.5% in hysteroscopy women and 21.1% in control women (OR: 1.9; 95%CI: 1.2-3.1; P = 0.008). The results of hysteroscopy were normal in 103 women (72.5%), and they revealed inflammation in 22 (15.5%), polyp in 16 (11.3%) and Asherman syndrome in one patient (0.7%).

CONCLUSIONS

Hysteroscopy in the menstrual cycle before ovarian stimulation in fresh cycles and before endometrial preparation in frozen thawed cycles in women experiencing recurrent implantation failure with apparently normal uterine cavity significantly increases the pregnancy rates in fresh and frozen cycles, respectively.

Assessment of pregnancy-associated, within-woman change in uterine length

OBJECTIVE

To evaluate how absolute uterine length changes as a result of pregnancy.

METHODS

Longitudinal repeated-measures study of all women presenting to a university-affiliated clinic for uterine sounding prior to in vitro fertilization (IVF) who went on to deliver at term and return for repeat measurement from 2002 to 2012. Change in uterine length was assessed by the Wilcoxon signed-rank test.

RESULTS

Among 495 women, mean pregnancy-associated change in uterine length was 0.0 cm (SD ± 0.7, p = 0.84), with 31% of women experiencing no change and 75% of women experiencing a change ≤0.5 cm. Mean uterine lengths at pre-cycle and repeat measurement were 7.2 cm (SD ± 0.7) and 7.2 cm (SD ± 0.7) with medians of 7.0 cm (IQR 7.0-7.5) and 7.0 cm (IQR 6.8-7.8), respectively. Change in uterine length did not vary by gestational number or within time interval between measurements (all p > 0.5).

CONCLUSIONS

There was no difference in uterine length before and after term pregnancy. The finding of minimal variation in uterine length both across and within women suggests uterine length may be relatively stable such that patients undergoing IVF after term IVF pregnancy may not require repeat measurement. Future studies might assess pregnancy-associated sonographic changes in uterine volume and the relationship between uterine length and IVF outcomes.

Uterine length and fertility outcomes: a cohort study in the IVF population

STUDY QUESTION

What is the relationship between pre-cycle uterine length and IVF outcome (chemical pregnancy, clinical pregnancy, spontaneous abortion and live birth)?

SUMMARY ANSWER

Women at extremes of uterine length (<7.0 or >9.0 cm) were less likely to achieve live birth and women with uterine lengths <6.0 cm were also more likely to experience spontaneous abortion.

WHAT IS KNOWN ALREADY

A prospective study of 807 women published in 2000 found that implantation and clinical pregnancy rates were highest in women with uterine lengths between 7.0 and 9.0 cm, though the difference was not significant. The relationship between pre-cycle uterine length and live birth has not been evaluated.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study of all cycles performed after uterine length measurement at an academic hospital IVF clinic from 2001 to 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 8981 fresh cycles were performed in 5120 adult women with normal uterine anatomy. Women with uterine anomalies (unicornuate, bicornuate, septate or uterus exposed to diethylstilbestrol) were excluded and women with fibroids were identified for subanalysis. Uterine length was measured by uterine sounding. Cycles were divided by uterine length into groups: <6.0 cm (very short, n = 76), 6.0-6.9 cm (short, n = 2014), 7.0-7.9 cm (referent, n = 4984), 8.0-8.9 cm (long, n = 1664) and ≥9 cm (very long, n = 243). Multivariate logistic regression (first-cycle analyses) and generalized estimating equations (all-cycle analyses) were adjusted for age, fibroids and ART treatment (assisted hatching, intracytoplasmic sperm injection) to generate relative risk (RR) of cycle outcomes by uterine length.

MAIN RESULTS AND THE ROLE OF CHANCE

Median uterine length in the IVF population was 7.0 cm (interquartile range 7.0-7.8) and was positively associated with BMI (P < 0.001) and fibroids (P = 0.02). Compared with the referent group, women with uterine lengths <6.0 cm were half as likely to achieve live birth (RR: 0.53; 95% confidence interval (CI): 0.35-0.81) and women with lengths of 6.0-6.9 cm were also less likely (RR: 0.91; CI: 0.85-0.98). Cubic regression spline identified a significant inverse U-shaped association whereby women with uterine lengths <7.0 or >9.0 cm were less likely to achieve live birth. Women with lengths <6.0 cm were also more likely to experience spontaneous abortion (RR: 2.16; CI: 1.23-3.78). Results remained consistent when excluding women with a uterine factor diagnosis (n = 8823), when limiting to the first cycle at our institution (n = 5120) and when further restricting to first-ever cycles (n = 3941).

LIMITATIONS, REASONS FOR CAUTION

Optimal assessment of uterine length by ultrasound was not feasible due to time and cost limitations, though uterine sounding is a clinically relevant measurement allowing for results with practical implications. Findings from our predominantly Caucasian clinic population may not be generalizable to infertile populations with different ethnic compositions.

WIDER IMPLICATIONS OF THE FINDINGS

Reproducibility of results would solidify findings and inform patient counseling in women undergoing IVF.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was sought for this investigation. MD declares relationships with UpToDate (royalties) and WINFertlity (consultant).

Association between Thrombophilia and Repeated Assisted Reproductive Technology Failures

PURPOSE

This study was performed to investigate the incidence of thrombophilic gene mutations in repeated assisted reproductive technology (ART) failures.

METHODS

The prevalence of mutated genes in the patients with a history of three or more previous ART failures was compared with the patients with a history of successful pregnancy following ARTs. The study group included 70 patients, 34 with three or more previously failed ARTs (A) and control group consisted of 36 patients with successful pregnancy following ARTs (B). All patients were tested for the presence of mutated thrombophilic genes including factor V Leiden (FVL), Methylenetetrahydrofolate reductase (MTHFR) and Prothrombin (G20210A) using real-time polymerase chain reaction (RT- PCR).

RESULTS

Mutation of FVL gene was detected in 5.9% women of group A (2 of 34) compared with 2.8% women (1 of 36) of control group (P = 0.6). Mutation of MTHFR gene was found in 35.3% (12 cases) as compared with 50% (18 cases) of control (35.3% versus 50%; P = 0.23). Regarding Prothrombin, only control group had 5.6% mutation (P = 0.49). No significant differences were detected in the incidences of FVL, Prothrombin and MTHFR in the study group A compared with the control group B.

CONCLUSION

The obtained results suggest that thrombophilia does not have a significant effect in ART failures.

Fertility, Infertility and Thrombophilia

Hypercoagulation has been reported in some studies to be associated with reproductive failures, such as unexplained infertility, IVF implantation failure and recurrent fetal losses. Many pregnancy-related disorders have been interpreted as consequences of impaired microvascular function and might be viewed as a mild form of venous thromboembolic disease. In the absence of clinical guidelines, there is a need for an evidence base regarding thrombophilic screening and antithrombotic therapy in cases of reproductive failure. This article will focus on the controversial effect of congenital and acquired thrombophilia on human fertility, and will review the English literature for relevant studies identified by searching PubMed® results between January 1966–November 2010 using the key words: ‘thrombophilia‘, ‘fertility’ and ‘infertility‘.

Uterine Cavity Assessment Prior to IVF

Approximately 15% of couples are affected with subfertility, of which up to 20% remain unexplained. Uterine cavity abnormalities can be a contributing cause of subfertility and recurrent implantation failure. Uterine cavity assessment has been suggested as a routine investigation in the evaluation of subfertile women. Traditionally, hysterosalpingography has been the most commonly used technique in the evaluation of infertility. Transvaginal ultrasound scan allows visualization of the endometrial lining and cavity, and has been used as a screening test for the assessment of uterine cavity. Abnormal uterine findings on a baseline scan can be further evaluated with saline hysterosonography, which is highly sensitive and specific in identifying intrauterine abnormalities. Hysteroscopy is considered as the definitive diagnostic tool to evaluate any abnormality suspected on hysterosalpingography, transvaginal ultrasound scan or saline hysterosonography during routine investigation of infertile patients. Minimally invasive hysteroscopes have minimized the pain experienced by patients during the procedure and made it feasible to use hysteroscopy as a routine outpatient examination. Following recurrent IVF failure there is some evidence of benefit from hysteroscopy in increasing the chance of pregnancy in the subsequent IVF cycle, both in those with abnormal and normal hysteroscopic findings. Various possible mechanisms have been proposed for this beneficial effect, but more randomized controlled trials are needed before its routine use in the general subfertile population can be recommended.

Relationship between the length of the uterine cavity and clinical pregnancy rates after in vitro fertilization or intracytoplasmic sperm injection

In this prospective clinical study involving 354 IVF-intracytoplasmic sperm injection cycles, we determined the influence of the length of the uterine cavity on clinical pregnancy rates. Our data showed that clinical pregnancy and implantation rates are associated positively with an increased length of the uterine cavity.

In-vitrofertilisation treatment: Factors affecting its results and outcome

The objective of this study was to determine factors affecting results and outcome of in-vitro fertilisation (IVF). In this retrospective study, a total of 891 infertile women underwent IVF/ICSI cycles at the King Hussein Medical Center (KHMC) between January 2001 and December 2002. Conventional IVF treatment was performed in 64.6% of women and intracytoplasmic sperm injection (ICSI) in 35.4%, using a standardised long luteal protocol. Pregnancy rate was analysed according to age, type of infertility, cause of infertility, duration of infertility, number of eggs collected and follicle stimulating hormone (FSH) levels. A total of 126 cycles (14.1%) were cancelled. Among 765 cycles continued, fertilisation rate was 73.9%, implantation rate was 15.1% and pregnancy rate was 29.8%. Pregnant women had a multiple pregnancy rate of 28.9%, abortion rate of 13.6% and ectopic pregnancy rate of 1.3%. Duration and type of infertility had no significant effect on the pregnancy rate. Factors which appear to affect significantly the outcome of treatment include the woman's age, cause of infertility, basal concentrations of FSH, adequate ovarian responsiveness and the number of eggs collected. In some cases with poor outcome, the understanding of these factors may predict the results and lead to the development of new strategies to improve the outcome of IVF treatment.

Utérus malformé et Assistance médicale à la procréation: prévention du défaut d'implantation?

The infertility in women with an abnormal uterus seems a subject of controversy. The prognosis of in vitro fertilization among these patients with such an anomaly is even less founded. The results of in vitro fertilization have been only studied with few patients and recently. Through the literature, we will focus step by step, on the impact of uterine anomalies on natural reproduction, then the impact of metroplasty on natural reproduction, the role of anomalies on the endometrium quality and lastly, the results of Assisted Rerpoductive Techniques with women with such an anomaly. It seems that the main risk is obstetric complications such as spontaneous abortion or premature delivery, not implantation failure. However, when infertility exists, surgical treatment tends to improve the pregnancy rate for some.

Bioengineering Studies of the Embryo Transfer Procedure

Embryo transfer (ET) is the final manual intervention in extracorporeal fertilization in which an embryo is transferred into the uterus by a transcervical catheter. The low rates of embryo implantation within the uterus are attributed, among other factors, to the ET technique, which depends on a multitude of anatomical, physiological, and mechanical aspects. We developed computational and experimental models to simulate ET to examine the contribution of mechanical features to the success of this procedure. The experimental model allowed laboratory simulations of the dispersion of the catheter load as a result of different injection speeds into a tilted uterine model. The mathematical model analyzed potential trajectories of the transferred embryos resulting from the interaction between the injection velocity and the intrauterine flows caused by uterine peristalsis. The simulations revealed the important contribution of mechanical parameters, such as the position of the uterus and the presence of air in the catheter load. The latter was found to increase the potential for the embryo to be near the fundal area during the time limit for implantation. Based on the results of our simulations, we recommended performing ET in a patient-specific position in which the fundus will be the highest point above the horizon and that the load be delivered slowly, that is, not less than 10 s. We also recommended placing the tip of the catheter at the mid cavity to avoid ectopic pregnancy.

The pre-cycle blind mock embryo transfer is an inaccurate predictor of anticipated embryo transfer depth

PURPOSE

To assess if the uterine cavity depth measured by a blind pre-cycle mock transfer changes after gonadotropin stimulation.

METHODS

This is a retrospective cohort study at an academic IVF program involving 128 infertility patients. The main outcome measures were uterine cavity depth measured at the blind pre-stimulation mock transfer and the ultrasound-guided embryo transfer.

RESULTS

A >or= 1 cm increase in uterine cavity depth was found in 57.9% of the patients. The mean pre-cycle blind mock transfer uterine depth significantly differed from the mean uterine depth measured at embryo transfer. Based on the mock transfer, the anticipated embryo transfer depth was significantly less than the actual ultrasound-guided embryo transfer depth.

CONCLUSION

Uterine depth significantly differed between the blind pre-cycle mock transfer measurement and the ultrasound-guided embryo transfer measurement. The mock transfer may predict a difficult embryo transfer but it is an inaccurate predictor of the final embryo transfer depth.

Removal of cervical mucus: effect on pregnancy rates in IVF/ICSI

Cervical mucus may cover the embryo transfer catheter during passage of the cervical canal, interfering with the correct placement of the embryo(s) into the uterine cavity. The effect of removal of cervical mucus prior to embryo transfer in IVF/ intracytoplasmic sperm injection (ICSI) on live birth rate was studied. The study was set up as a single blind randomized controlled trial. Couples undergoing IVF/ICSI were randomly allocated to either removal of cervical mucus prior to embryo transfer, or a mock procedure. Randomization was done with stratification for age, cycle number and method of treatment. Primary outcome was live birth rate. A total of 317 couples were included and underwent 428 cycles, of which the outcome of 3 cycles was unknown. Baseline characteristics of both groups were comparable. Live birth occurred in 52 of 220 (24%) cycles in the treatment group and 42 of 205 (21%) cycles in the control group (risk difference 3%, 95% confidence interval-5- 11%). It is unlikely that removal of cervical mucus prior to embryo transfer has a significant effect on live birth rate. A small effect, however, cannot be excluded.

Acquired and inherited thrombophilia: implication in recurrent IVF and embryo transfer failure

BACKGROUND

The objective of this study was to determine the incidence of undiagnosed thrombophilic factors and its relation to IVF and embryo transfer failure in women who have had three or more previous IVF-embryo transfer cycles.

METHODS

The study group comprised of 90 consecutive women with three or more previously failed IVF-embryo transfer cycles (group A). Two control groups were enrolled: group B (n=90) included women who have had successful pregnancy after their first IVF-embryo transfer cycle, and group C (n=100) included women who conceived spontaneously with at least one uneventful pregnancy and no previous history of miscarriage. All women were tested for the presence of inherited [factor V Leiden (FVL) mutation, prothrombin mutation, methylenetetrahydrofolate reductase (MTHFR) mutation and deficiencies in proteins S and C and antithrombin III] or acquired (lupus anticoagulant and anticardiolipin) thrombophilic factors.

RESULTS

An increase in the incidences of FVL, MTHFR and antiphospholipid antibodies was found in the study group compared with the two control groups. At least one inherited or acquired thrombophilic factor was detected in 68.9% of women with repeated IVF failure compared with 25.6 and 25% in the groups B and C, respectively (P<0.01). Combined thrombophilia (two or more thrombophilic factors) was significantly higher in women who have had repeated IVF failure as compared with the two control groups (35.6 versus 4.4 and 3%) (P<0.0001).

CONCLUSION

Thrombophilia has a significant role in IVF-embryo transfer implantation failure. Women with repeated IVF-embryo transfer failure should be screened for thrombophilia.

The retroverted uterus: ignored to date but core to prolapse

The retroverted uterus has been largely ignored in urogynaecological research to date. The prevalence of the retroverted uterus is 79% more common in the urogynaecological patient population (34%) than in the general gynaecological population (19%). Its diagnosis requires the use of (a) transvaginal ultrasound with (b) an empty bladder. Recent data demonstrate that the prevalence of grade 2-4 uterine prolapse for a retroverted uterus is 4.5 times that for an anteverted uterus. Alternatively, 69% grade 2-4 uterine prolapse involves the retroverted uterus. The retroverted uterus, when diagnosed by transvaginal ultrasound (bladder empty), is far more common in urogynecology patients due to their higher incidence of prolapse.

Implantation sites after embryo transfer into the central area of the uterine cavity

A total of 63 pregnancies (47 singleton, 15 twin, 1 triplet) from intracytoplasmic sperm injection cycles were analysed. In all embryo transfers, the catheter was introduced into the endometrial cavity guided by abdominal ultrasound, with the catheter tip placed at the middle point of the endometrial cavity. Gestational sacs (GS) were located 21-24 days after transfer (gestational age=5 weeks) by two-dimensional and three-dimensional transvaginal ultrasound. The uterine cavity was divided into three parts: upper, middle and lower. Furthermore, the upper region was subdivided into right, middle and left areas, and the middle region was subdivided into right and left areas. The frequency of gestational sacs in each area was evaluated. In singleton pregnancies 66.0% (31/47) of the GS were detected in the upper region, 29.8% (14/47) in the middle region and 4.2% (2/47) in the lower region. In multiple pregnancies (twins and triplet) 45.5% (15/33) of the GS were detected in the upper region, 51.5% (17/33) in the middle region and 3.0% (1/33) in the lower region. In conclusion, the results demonstrate that when embryos are transferred to the central area of the uterine cavity there is an increase in implantation rate in the middle region compared with the rate expected in naturally conceived pregnancies (9-15%).

Womb with a view

Zygote transfer is a significant limiting factor in pregnancy rates after Assisted Reproductive Technology (ART) treatment. Adequate technique appraisal should be a high priority task for any medical facility that offers this treatment. Although many clinicians have extensive personal experience, it is difficult for trainees to understand the anatomical and mechanical process of safe and adequate placing of zygotes in the uterine cavity. Ultimately, even with ultrasound help, it is a "blind procedure". The experimental module described here allows for direct visualisation of the mechanical passage of a catheter through the cervix and final placement of the tip in relation to the intravaginal visible part of the catheter. It has worldwide practical applicability for trainees and experienced clinicians accompanying the theory and allowing adequate training and retraining of all staff performing zygote transfers.

Implantation Failure in Assisted Reproduction Technology and a Critical Approach to Treatment

In this article, we review the literature and our personal experience regarding the many factors that appear to influence implantation rate. Oocyte quality, as determined by patient age and aneuploidies, probably plays a major role in RIF. However, a panoply of other factors have been brought under investigation, quite often with contradictory results and additional intriguing questions to be studied. Infections of the vagina, cervix, and endometrium, the role of mucus aspiration and washing of the cervix on transfer, the role of catheter guidance for a correct transfer and potion of embryos, the effect of mock transfer, and the role of hysteroscopy and its timing before transfer procedures are analyzed both as a review of the literature and as opinions and data from our experience. Many of these factors are interlaced and from the apparently simple issue of trauma, to infections and immune modulation of hatching and implantation, a biological continuum can easily be identified. The impact of abnormalities of the immune system and of homeostasis abnormalities is also covered in a brief overview of reported works and our experience. These latter areas probably constitute the common biological background of all other external factors that, however, the skilled must equip themselves for improving implantation success.

The Impact of Embryo Transfer on Implantation—A Review

Embryo transfer has received little clinical attention and has been, until recently, the most inefficient step in in-vitro fertilization (IVF). In this article, the authors review the literature and their personal experience regarding the process of intrauterine transfer of embryos, which remains the object of much discussion. Factors which appear to influence implantation rates are: contamination of the catheter tip with cervical bacteria, stimulation of uterine contractions during the procedure, the type of catheter, ultrasound guidance during the transfer, and the position of the embryos in the uterine cavity. Easy and atraumatic transfer is essential for successful implantation and the embryos need to be placed in the middle of the cavity, away from the fundus. Knowing, beforehand, the position and length of the uterus can provide better results and may reduce the rate of ectopic pregnancies. Evidence from randomized studies has supported this claim. Despite the number of available studies controlling certain variables, most authors, even using the same catheter, ultrasound guidance and/or a trial transfer use different protocols or similar instruments in different ways. Standardization of the transcervical intrauterine transfer of embryos in a large randomized study is needed before definitive conclusions can be drawn. The goal of improved implantation and pregnancy rates deserve these efforts.

Impact of technical difficulties, choice of catheter, and the presence of blood on the success of embryo transfer--experience from a single provider

PURPOSE

To investigate the impact of technical difficulties, choice of catheter, and the presence of blood during embryo transfer on the results of in vitro fertilization and ICSI.

METHODS

A cohort of 784 consecutive cycles in 655 in vitro fertilization and ICSI patients were studied.

RESULTS

Negotiating the cervix, using the volsellum, presence of blood on the catheter wall or on the cervix did not affect the results. Changing the catheter and blood on the catheter tip reduced the pregnancy (P < 0.05 and P < 0.05) and implantation rates (P < 0.001 and P < 0.01). The Ultrasoft catheter produced higher pregnancy (P < 0.0005) and implantation rates (P < 0.01) compared to the more rigid Frydman catheter.

CONCLUSIONS

Negotiation of the cervix, the use of a volsellum, and the presence of blood on the catheter wall or on the cervix do not affect the results. Changing the catheter and blood on the catheter tip significantly diminish the pregnancy and implantation rates. Soft catheters perform better.

Ultrasound measurement of the uterocervical angle before embryo transfer: a prospective controlled study

BACKGROUND

The study aim was to determine whether moulding the embryo transfer catheter according to the uterocervical angle measured by ultrasound could improve pregnancy and implantation rates.

METHODS

Patients were alternately allocated to one of two groups. In the ultrasound-guided group (n = 320), the catheter was moulded according to the uterocervical angle measured by abdominal ultrasound. In controls (n = 320), embryo transfer was performed using the "clinical feel" method.

RESULTS

Moulding the embryo transfer catheter according to the uterocervical angle significantly increased clinical pregnancy [(OR = 1.57, 95% CI (1.08-2.27)] and implantation rates [(OR = 1.47, 95% CI (1.10-1.96)] compared with the "clinical feel" method. It also significantly reduced difficult transfers [(OR = 0.25, 95% CI (0.16-0.40)] and blood during transfers [OR = 0.71, 95% CI (0.50-0.99)]. Patients with large angles (>60 degrees ) had significantly lower pregnancy rates compared with those with no angle [OR = 0.36, 95% CI (0.16-0.52)].

CONCLUSIONS

Moulding the embryo transfer catheter according to the uterocervical angle measured by ultrasound increases clinical pregnancy and implantation rates and diminishes the incidence of difficult and bloody transfers.

Clinical practice of embryo transfer

In this review, several embryo transfer methods are considered, together with factors involved in achieving an effective transfer. The approach most used is transcervical intrauterine transfer. This is described in detail, together with the many variables influencing success, e.g. technical ability and training of personnel, catheter choice, value of a previous 'dummy transfer' and the need to minimize trauma during transfer and so prevent damage to the uterine lining, bleeding and uterine contractions. These factors can each negatively impact on pregnancy rates. Emphasis is put on quality, developmental stage and number of embryos to be transferred to limit multiple pregnancies and their unwanted side-effects. Culture to blastocyst stages and single embryo transfer when optimal quality embryos are available are discussed as means of avoiding multiple pregnancies. Reference is made to embryo cryopreservation and fertility following frozen embryo transfer. Other techniques, such as ultrasound-controlled transcervical intrauterine transfer, and ultrasound-controlled transmyometrial transfer, are reviewed. More invasive procedures, generically grouped as surgical embryo transfer, including gamete intra-Fallopian transfer (GIFT), zygote intra-Fallopian transfer (ZIFT), pronuclear stage transfer and embryo intra-Fallopian transfer (EIFT), are also described. These techniques had a place in IVF when the need to apply assisted reproductive techniques exceeded the capacity of most laboratories, but not today thanks to refined laboratory technology and improved understanding of implantation. Alternative assisted reproductive technologies, such as direct intra-follicular insemination (DIFI), Fallopian spermatic perfusion (FSP), peritoneal oocyte stage and sperm transfer and intra-vaginal culture (IVC), are mentioned briefly.