Mutations in hepatitis B DNA polymerase associated with resistance to lamivudine do not confer resistance to adefovir in vitro

A total of 96 women undergoing in-vitro fertilization (IVF) treatment were examined by transvaginal ultrasonography with colour and pulsed Doppler ultrasound on the 22nd day of the menstrual cycle preceding IVF. We assessed endometrial thickness, endometrial morphology, myometrial echogenicity, subendometrial vascularization, the uterine artery pulsatility index, protodiastolic notch and end diastolic blood flow in order to define a uterine score which could be correlated with the pregnancy rate. The overall pregnancy rate was 30.2%, and there was no difference between the pregnant and non-pregnant groups with regard to any of the ultrasonographic and Doppler parameters when examined separately. However, the uterine score was significantly higher in the pregnant group (15.9 +/- 2.81 versus 12.7 +/- 5.3, P = 0.002; t-test). No pregnancy occurred if the score was between 0 and 10. With a score of 11-15 there was a 34.7% chance of pregnancy, and scores >16 had a 42% chance of pregnancy. In conclusion, individual ultrasonographic and Doppler parameters are not of sufficient accuracy to predict uterine receptivity. The uterine score calculated prior to IVF cycles appears to be a useful predictor of implantation.     

Paired human chorionic gonadotrophin determinations for the prediction of pregnancy outcome in assisted reproduction

The aim of this study was to determine the prognostic value of single and paired measurements of serum concentrations of human chorionic gonadotrophin (HCG) for successful pregnancy following in-vitro fertilization (IVF) and tubal embryo transfer (TET). We analysed serum HCG concentrations 15 and 22 days after IVF or TET in 198 conception cycles. Cut-off values of serum HCG were determined by a receiver operating characteristic (ROC) curve. On the basis of single HCG samples on day 15 (HCG15) after transfer, using a cut-off value of HCG15 = 150 mIU/ml, the sensitivity was 71% and the specificity was 77%. The positive predictive value (HCG15 > or = 150 mIU/ml indicating a normal pregnancy) was 89%, while the negative predictive rate (HCG15 < 150 mIU/ml indicating an abnormal pregnancy) was 51%. Patients with HCG15 < 150 mIU/ml but HCG22/HCG15 ratio > or = 15, still had a 90% chance of normal pregnancy. However, in patients with HCG15 < 150 mIU/ml and an HCG22/HCG15 ratio < 15, there was an 84% chance of an abnormal pregnancy. We conclude that a single HCG15 determination combined with the ratio of HCG22 to HCG15 has a higher diagnostic accuracy for prediction of pregnancy outcome than either analysis alone.     

The selection criteria on an IVF program can remove the association between maternal age and implantation

BACKGROUND: 1190 consecutive in vitro fertilization (IVF) treatment cycles from the Southampton University/BUPA Chalybeate unit, spanning a four year period, were studied retrospectively in order to assess the relationship between maternal age and implantation. Our aim was to evaluate the hypothesis that the number of transferred embryos can be determined by age alone. METHOD: The cases were allocated to two age groups, Group 1 was composed of patients of less than or equal to 35 years of age and Group 2 of patients greater than 35 years of age. RESULTS: We found that the selection criteria used in our programme for abandoning treatment cycles led to significantly more older patients being excluded from oocyte collection (p < 0.001). The patients from both groups that progressed to oocyte collection and embryo transfer showed no significant difference in embryo implantation. The overall implantation rate (12.4%) and clinical pregnancy rate per embryo transfer (22.8%) were achieved by being able to transfer comparable numbers of embryos in both age groups and in spite of the younger age group having a significantly better quality of transferred embryos. CONCLUSION: Although advancing maternal age predisposes to a reduced chance of success from IVF treatment, maternal age alone was not a useful predictor of embryo implantation or endometrial receptivity in completed IVF treatment cycles.     

Serum progesterone at the time of human chorionic gonadotrophin does not predict pregnancy in in-vitro fertilization and embryo transfer

Controversy exists as to whether the serum concentration of progesterone on the day of human chorionic gonadotrophin (HCG) administration following ovarian stimulation for in-vitro fertilization (IVF) and embryo transfer can be used to predict the likelihood of success. This retrospective study was undertaken to answer this question by analysing a large population of IVF and embryo transfer cycles (n = 756). In addition to the concentration of progesterone on the day of HCG administration, all variables known to impact on IVF and embryo transfer success (such as patient age), indication for IVF and embryo transfer, number of oocytes retrieved and the number of embryos generated and transferred were examined. There was a significant increase in the number of oocytes retrieved with increasing progesterone concentration at the time of HCG administration. However, there was no correlation of progesterone concentration at HCG administration with pregnancy and implantation rates. It is concluded that previous reports associating a slight elevation of progesterone in gonadotrophin-releasing hormone agonist ovarian stimulation cycles for IVF and embryo transfer may be misleading because of a small sample size or the presence of confounding variables that affect IVF and embryo transfer success.     

Gaucher''s disease suspected by abdominal echography findings

PURPOSE: To evaluate the contribution of embryo quality to preclinical loss rates after in vitro fertilization (IVF)/embryo transfer (ET) pregnancy, multiple gestation, and clinical loss rates were compared to preclinical pregnancy loss rates over a 3-year period. METHODS: The pregnancy outcomes after 1675 fresh ETs from 1994 to 1997 were studied. While establishment of a clinical pregnancy confirms uterine receptivity, multiple gestation rates reflect embryo quality. Because the majority of clinical losses are chromosomally abnormal, clinical loss rates serve as another indicator of embryo quality. RESULTS: The overall preclinical pregnancy loss rate was 5% (78/1675) of ETs and 17% (78/472) of pregnancies. During the 3-year period the pregnancy rates per ET increased from 19 to 36% (P < 0.0001), multiple gestation rates increased from 21 to 48% (P < 0.008), clinical loss rates decreased from 20 to 6% (P < 0.0001), and preclinical pregnancy loss rates remained unchanged from 13 to 19% (P = 0.1). CONCLUSIONS: Preclinical pregnancy loss more likely reflects abnormalities in uterine receptivity rather than embryo quality. If recurrent preclinical pregnancy loss occurs after IVF/ET, evaluation for abnormalities of uterine receptivity should be performed.     

Parametric changes in response equilibrium during an intra-cranial self stimulation (ICSS) task: can reward value be assessed independently of absolute threshold?

A prospective randomized study was conducted to measure the serial thickness of the lower uterine segment (LUS) by transvaginal ultrasonography in a control group of 80 women having no history of uterine surgery and in a study group of 43 women having a history of previous cesarean section (C/S). In the study group, more than 2 mm of thickness of the LUS was considered as good healing and less than 2 mm of thickness as poor healing. After serial sonographic examination, the women with good healing were given trial for labor unless an obstetrical indication for C/S existed. The appearance of the LUS during surgery was compared with antenatal ultrasonographic assessment by direct inspection. Twenty two (79%) of 28 women with a well healed scar had trial labor with the result that 46% had a successful vaginal birth without any uterine rupture of dehiscence. Eight women with poor healing all had elective C/S. Seven women with a 2 mm LUS thickness were individually categorized for delivery mode. Two of those women delivered vaginally. The LUS was found to be thin to translucent in these later two groups. Two mm or less as a criterion for poor healing had the sensitivity and specificity of 86.7% and 100% respectively. The positive predictive value was 100% and the negative predictive value was 86.7%. Ultrasonographic evaluation is effective in predicting the quality of a uterine scar and in differentiating the risk group of probable uterine rupture from the non risk group.     

The hormonal control of endometrial receptivity: estrogen (E2) and progesterone

While the number of identified substances produced by the ovary increases steadily, it remains remarkable that the sole use of exogenous estrogen (E2) and progesterone (P) can prime optimal endometrial receptivity in women whose ovaries have failed or are absent. Early work showed that a marked leeway existed in the acceptable duration of the E2-only phase of endometrial priming. Subsequently, a sequence of transformations are induced by exogenous progesterone that reproduces classical findings made in the menstrual cycle. Secretory changes in endometrial glands are best seen between the 4th and 6th day of progesterone administration (day 18-20 of an ideal cycle where progesterone exposure starts on day 15). Predecidual changes of the endometrial stroma are apparent starting on the 10th day of progesterone exposure (day 24). Contrary to earlier belief, even maximal alterations in the plasma E2 to progesterone ratio fails to alter the endometrial morphology of either glands or stroma. More recently it has been recognized that E2 and progesterone also affect uterine contractility. It has been postulated that excessively high levels of E2 may increase uterine contractility and adversely affect implantation rates in in-vitro fertilization (IVF). Exogenous progesterone has been shown to exert utero-relaxing effects and it has been hypothesised that progesterone supplementation before embryo transfer (ET) may improve receptivity in IVF.     

Long-term evaluation of implantation of fresh and cryopreserved human embryos following ovarian stimulation with buserelin acetate-human menopausal gonadotrophin (HMG) or clomiphene citrate-HMG

This study is a long-term evaluation of the total pregnancy potential of cohorts of fresh and cryopreserved sibling embryos from in-vitro fertilization (IVF) cycles stimulated with either the gonadotrophin-releasing hormone analogue buserelin (BUS) (long protocol) or clomiphene citrate (CC) both in combination with human menopausal gonadotrophin (HMG). Therefore a retrospective analysis was performed on patients who entered the IVF programme between January 1986 and July 1987 and who had triple embryo transfer in the collection cycle. Significantly more fertilized oocytes developed to good-quality embryos in the CC-HMG group (86.1%) than in the BUS-HMG group (80.8%). Transfer of the three morphologically best-looking embryos was performed in day 2 post-insemination in 106 CC-HMG and 80 BUS-HMG cycles. Supernumerary embryos were cultured for a further 24 h and multicellular embryos with up to 20% of fragments were frozen slowly with 1.5 M dimethylsulphoxide on day 3 post-insemination (162 embryos in CC-HMG cycles, 102 embryos in BUS- HMG cycles). Outcome was measured by embryo survival rate, embryo implantation rate and delivery rate in fresh and frozen embryo transfers. Delivery rates were 31.3 and 21.7% per fresh embryo transfer in BUS-HMG and CC- HMG cycles respectively. Fresh embryo implantation rates were significantly higher in collection cycles stimulated with BUS-HMG (17.9%) than in cycles stimulated with CC-HMG (11.3%). Implantation rates were significantly enhanced in embryos transferred in excess of one in cycles leading to pregnancy, perhaps indicative of higher embryo quality in BUS-HMG cycles. Almost all cryopreserved embryos have by now been thawed, so the contribution of frozen embryos to overall pregnancy rates can be evaluated. Overall morphological survival rates of frozen-thawed embryos have by now been thawed, so the contribution of frozen embryos to overall pregnancy rates can be evaluated Overall morphological survival rates of frozen-thawed embryos were similar for 140 embryos from CC-HMG cycles (50%) and 100 embryos from BUS-HMG cycles (46%). The percentage of fully intact embryos was, however, significantly lower in the BUS-HMG group (19%) than in the CC-HMG group (39.5%). Delivery rates were significantly lower following 30 transfers of frozen-thawed embryos from BUS-HMG-stimulated cycles (3.3%) than following 42 transfers of frozen-thawed embryos from CC-HMG cycles (19.1%). Embryo implantation rates were lower for frozen-thawed embryos from BUS-HMG cycles (2.3%) than from CC-HMG cycles (12.7%). Here we demonstrate that ovarian stimulation with the long protocol BUS-HMG instead of the CC-HMG protocol led to higher embryo implantation rates in collection cycles but to lower intact embryo survival rates and to lower embryo implantation rates for frozen sibling embryos. Despite the lower implantation rates with frozen embryos originating from the BUS-HMG protocol, there was no significant difference between total delivery rate per transfer from cycles stimulated with CC-HMG (30.2%) compared with BUS-HMG (33.8%).     

Uterine contractions at the time of embryo transfer alter pregnancy rates after in-vitro fertilization

To investigate the possible consequences of uterine contractions (UC) as visualized by ultrasound (US) on in-vitro fertilization (IVF)-embryo transfer outcome, we studied prospectively 209 infertile women undergoing 220 cycles of controlled ovarian stimulation. Inclusion criteria were age < or = 38 years, a morphologically normal uterus, and at least three good quality embryos transferred. Just before embryo transfer, women underwent 5 min digital recordings of the uterus using US image analysis software for UC assessment. Plasma progesterone and oestradiol concentrations were measured. Four groups were defined according to UC frequency: < or = 3.0 (n = 53), 3.1-4.0 (n = 50), 4.1-5.0 (n = 43), and > 5.0 (n = 74) UC/min respectively. Patients, controlled ovarian hyperstimulation and embryology characteristics were comparable in all groups. A stepwise decrease in clinical and ongoing pregnancy rates as well as in implantation rates occurred from the lowest to the highest UC frequency groups (53, 36, 21; 46, 32, 20; 23, 19, 10; and 14, 11, 4%; P < 0.001). Plasma progesterone and UC frequency were negatively correlated (r = -0.34, P < 0.001). Direction of UC did not affect embryo transfer outcome. As this study was controlled strictly for confounding variables and UC were assessed objectively by a computerized system, its results indicate that high frequency UC on the day of embryo transfer hinder IVF-embryo transfer outcome, possibly by expelling embryos out of the uterine cavity. The negative correlation between UC frequency and progesterone concentrations supports the uterine relaxing properties of progesterone.     

Bracken fern carcinogenesis: multiple intravenous doses of activated ptaquiloside induce DNA adducts, monocytosis, increased TNF alpha levels, and mammary gland carcinoma in rats

A matched follow-up study design was used to test the hypothesis that pregnancy rates following assisted reproduction procedures do not differ between women with or without intramural or sub-serosal uterine leiomyomas. Women undergoing their first in-vitro fertilization (IVF)-embryo transfer or zygote intra-Fallopian transfer (ZIFT) cycle between January 1993 and June 1995 were included. Cases (women with leiomyomas) were matched 1:1 with the next consecutive control (women without leiomyomas) according to age, number of embryos transferred, embryo grade, and the route of embryo transfer (uterine or Fallopian). Assisted reproduction cycles were performed in an identical manner, independent of the presence or absence of uterine leiomyomas. The main outcomes measured were clinical pregnancy and delivery rates. A total of 182 cycles was evaluated. Of the 91 assisted reproduction cycles performed in the leiomyoma group, there were 34 clinical pregnancies (37%) and 30 deliveries (33%). Of the 91 assisted reproduction cycles in the control group, there were 48 clinical pregnancies (53%) and 44 deliveries (48%). The Mantel-Haenszel estimate of relative risk indicated that the presence of a uterine leiomyoma significantly reduced the chance for a clinical pregnancy or delivery. These findings suggest that leiomyomas are associated with a reduction in the efficacy of assisted reproduction cycles.     

The role of transvaginal ultrasonography and outpatient diagnostic hysteroscopy in the evaluation of patients with menorrhagia

To verify the reliability of transvaginal ultrasonography in diagnosing intrauterine disease and in evaluating the operability of submucous myomas and to determine the feasibility, acceptability and validity of hysteroscopy for menorrhagia, we performed a prospective 5 year study on 793 women of mean age +/- SD of 41.5 +/- 7.8 years. All the patients referred for excessive menstrual bleeding with uterine volume <12 week pregnancy who underwent complete physical examination, transvaginal ultrasonography and outpatient hysteroscopy with endometrial biopsy were included in the study. Outpatient hysteroscopy was not completed due to intolerance or was unsatisfactory due to excessive bleeding in 23 cases (2.9%). Only 28 women (3.5%) declared they would have refused the procedure had they imagined the pain involved. One case of pelvic infection was observed. Compared with hysteroscopy, transvaginal ultrasonography had 96% sensitivity, 86% specificity, 91% positive predictive value and 94% negative predictive value in the diagnosis of intrauterine abnormality. The sensitivity, specificity, positive and negative predictive values of ultrasonography in identifying submucous myomas operable hysteroscopically (intramural extension <50%) were respectively 80, 69, 83 and 65% with a k index of agreement between ultrasonography and hysteroscopy of 0.48. Thus, considering the good specificity and high negative predictive value, transvaginal ultrasonography may be suggested as the initial investigation in menorrhagic patients, limiting hysteroscopy to cases with positive or doubtful sonographic findings.     

The first three weeks assessed by transvaginal color Doppler

Transvaginal color Doppler has made possible to study ovarian and uterine perfusion in non-pregnant and pregnant patients, thus advancing the understanding of the early human development. RI of follicular blood flow starts decreasing prior to ovulation reaching its nadir at ovulation. It is considered that apart from hormonal factors the angiogenesis is also involved. The mature corpus luteum shows increased blood flow velocity in relation to preovulatory follicle. Comparing RI values of luteal blood flow of normal and ectopic pregnancy no difference was found. But in threatened, incomplete and missed abortions the resistance and pulsatility indices were significantly higher than in normal pregnancy. The follow up of the luteal flow might have a prognostic value in a group of patients with threatened abortion. In women with spontaneous cycles the day preceding the ovulation impedance to uterine flow velocity starts decreasing. Alterations in flow velocity patterns of the radial and spiral arteries in spontaneous ovulatory cycles are paralleling blood flow dynamics of the uterine arteries. In stimulated cycles RI increases the day before ovulation in both the uterine arteries and their branches. It seems that endometrial perfusion presents more accurate noninvasive assay of uterine receptivity than uterine artery perfusion alone. Endometrial receptivity is maximum during the time of peak luteal function during which implantation is most likely to occur. During the pregnancy impedance to blood flow decrease from the main uterine to the spiral arteries as well as with the advancing gestational age. The spiral arteries in pregnancy become the vessels with completely different haemodynamic characteristics in relation to other arteries of uteroplacental circulation. Color Doppler adds new information on perfusion and pathophysiological changes connected with the ectopic trophoblast implantation.     

Permanent impairment of embryo development by hydrosalpinges

Recent reports suggest a deleterious effect of hydrosalpinges on pregnancy outcome for in-vitro fertilization (IVF) and improvement following surgical treatment. We compared the effect of hydrosalpinx on pregnancy outcome in 286 patients having 348 IVF cycles and followed the development of untransferred embryos for 7 days to determine if hydrosalpinges affect oocyte quality or embryo development. The delivery rate per retrieval was significantly lower for patients with hydrosalpinx, but was restored by surgical treatment to that of patients without hydrosalpinx. However, the implantation rate per embryo transferred and normal blastulation of untransferred embryos, which were significantly decreased in patients with hydrosalpinx, and growth arrest and degeneration of untransferred embryos, which were significantly increased compared to patients without hydrosalpinx, were not restored by surgical treatment of hydrosalpinges. We conclude that surgical treatment of hydrosalpinges decreases early pregnancy loss and improves pregnancy outcome, possibly by diminishing reversible deleterious effects exerted on the endometrium. As we have seen in our laboratory, hydrosalpinges may have a permanent negative influence on ovarian function, follicular development and oocyte quality since implantation of transferred embryos and normal blastulation of untransferred embryos remain low, and in-vitro growth arrest and degeneration remain high despite surgical treatment of hydrosalpinges.     

Endocrine factors associated with recurrent spontaneous abortion

The role of endocrine factors as a cause of recurrent spontaneous abortion is controversial. Diabetes mellitus and thyroid disease do not represent a significant risk factor for recurrent pregnancy loss. Luteal-phase defect has been questioned because there are no accurate methods for diagnosis and no convincing evidence of correction with treatment exists. The corpus luteum is an unusual endocrine gland, highly diverse in function and important for successful reproduction in all mammalian species. Much controversy exists about the luteal function in humans and how defects in luteal function affects reproduction. Disagreement has been due to lack of accurate diagnosis and controlled studies to determine whether correction of the luteal-phase defect is worthwhile when treating female reproductive problems. The donor egg recipient model from assisted reproductive technology programs has shown that corpus luteum function can be replaced by estrogen and progesterone administration. The mechanism by which these steroids stimulate a uterus to be receptive to implantation of the embryo is not known. Several proteins produced by the endometrium are candidate markers for uterine receptivity. Further work needs to be done to correlate these markers with subsequent pregnancy outcome. A noninvasive marker for uterine receptivity is ultrasonographic evaluation of the endometrium. Although the sensitivity of this test is high (100%), its specificity is low (only 20% to 60%).     

Color echo-Doppler and endometrial receptivity in in vitro fertilization

The chances of nidation after in vitro fertilization procedures are contingent upon the development potential of the transferred embryo(s), but they also depend on the receptivity of the endometrium and on the uterine vascular supply. It is generally accepted that the chances of pregnancy are practically nil: if the endometrium is less than 8 mm thick, and/or if the uterine pulsatility index (PI) is below 3. However, the predictive value of the Doppler evaluation alone is poor to the extent that other parameters require consideration, such as the aspect of the endometrium and/or the number of embryos transferred. This is why our group initiated a prospective study on 213 patients designed to validate a 10 point scale based on: -the PI of each uterine artery on the day of transfer; -the features of the protodiastolic notch (absent, moderate or clearcut); -the thickness of the endometrium; -the number of embryos transferred. Each parameter by itself had a poor predictive value: optimal values of endometrium thickness and pulsatility index (PI) predicted a 29% and 33% pregnancy rate, which is hardly higher than our overall pregnancy rate (24%). By contrast, a score that encompasses all these parameters increased predictive value, with a score > 9 the probability of pregnancy reach 53% and the one of multiple pregnancy 24%. Our results emphasize the usefulness of a score prior embryo transfer which should be used to adjust the number of embryos transferred. When the score is higher than 10 transferring 2 embryos will prevent the risk of multiple pregnancy. 3 embryos should be transferred when the score is between 7 and 10, and a bad score (< or = 6) should delay the transfer.     

Embryo transfer--can we learn anything new from the observation of junctional zone contractions?

To assess whether embryo transfer can alter junctional zone contractility, we studied the effect of easy and difficult mock transfers in 14 oocyte donors during in-vitro fertilization (IVF) cycles. An Echovist bolus (30 microl) was used to represent embryos and transfer medium. An 'easy' transfer was judged to be an atraumatic insertion of the catheter without touching the uterine fundus. A 'difficult' embryo transfer was mimicked by deliberately touching the uterine fundus twice with the soft end of the cannula. Transvaginal scan images were recorded, digitized and converted into five times normal speed to allow us to evaluate junctional zone contractility. Easy mock embryo transfers did not change endometrial mechanical activity. Echovist remained in the upper part of the uterine cavity and was not dispersed after 45 min. A difficult procedure generated strong random waves in the fundal area and waves from fundus to cervix which relocated the Echovist in six out of seven cases. We observed movements of the transfer bolus from the upper part of the uterus towards the cervix (four cases) and into Fallopian tubes (two patients). Our study confirms that the mechanical activity of the uterus is capable of relocating intrauterine embryos and that this activity depends on physical stimulation. Junctional zone contractions can be implicated in cases of IVF/embryo transfer failure or ectopic gestation.     

Effect of profound suppression of luteinizing hormone during treatment with gonadotrophin-releasing hormone analogue and purified follicle stimulating hormone upon development of cryopreserved embryos

In response to previously published evidence from monkeys, this study examined the influence of the degree of luteinizing hormone (LH) suppression during the follicular phase of the stimulation cycle, upon cryopreserved embryo survival and development. The LH concentration of the mid-follicular phase was assessed in 250 in-vitro fertilization (IVF) cycles treated with gonadotrophin-releasing hormone analogue (GnRHa) and either purified follicle stimulating hormone (FSH) or human menopausal gonadotrophin (HMG), and was related to the performance of cryopreserved embryos in 351 subsequent embryo transfer cycles. Rates of embryo survival, embryo development rates, implantation rates, and pregnancy rates were examined with respect to the LH concentration recorded in the mid-follicular phase. In contrast to experimental evidence from other primates, there was no significant influence of the follicular phase LH concentration upon any of the parameters examined.     

Transrectal electroejaculation combined with in-vitro fertilization: effective treatment of anejaculatory infertility due to spinal cord injury

Infertility due to spinal cord injury (SCI) in young men is a frequent complication of their injury. When the simpler methods of management of the erectile and ejaculatory dysfunction that invariably follow the more severe types of SCI are not effective, then semen production by transrectal electroejaculation (TREE) combined with in-vitro fertilization (IVF) and embryo transfer is effective. A retrospective analysis is presented of data on the treatment and outcome of 35 couples who wished to have a family but in whom the male partner had suffered SCI. These 35 couples had 71 attempts at IVF with spermatozoa obtained following TREE. Normal fertilization and cleavage of the embryos occurred in 48.2% of the oocytes. Fresh embryos were transferred in 54 cycles and frozen-thawed embryos in 14 cycles. In all, 18 clinical pregnancies were achieved in 54 fresh and 14 frozen embryo transfer cycles, with a live birth rate of 16.5% (14/85) per treatment cycle started, 20.6% (14/68) per transfer cycle and 40.0% (14/35) per couple who started treatment, in a mean of 1.9 transfer cycles. We conclude that TREE combined with IVF and embryo transfer is an effective treatment for the infertility problems associated with SCI.     

Evaluating effects of exposures on embryo viability and uterine receptivity in in vitro fertilization

We consider models for the occurrence of pregnancy following in vitro fertilization. In this clinical protocol, implantation depends on two factors: the receptivity of the uterus and the viability of at least one of the embryos transferred to the uterus. This work is motivated by the need to identify reliable bio-markers for these two factors, in order to enhance the success rate for couples undergoing this procedure. We present a general latent variable structure model for outcomes that take either one of two possible forms: as summed Bernoullis, based on an ultrasound count of gestational sacs, or as aggregated Bernoullis, based only on the outcome of a biochemical pregnancy test. We allow both uterine receptivity and embryo viability to be influenced by covariates. The proposed latent variable structure allows us to utilize the existing statistical packages to maximize an otherwise intractable likelihood function. The method is sufficiently flexible to permit any valid choice of link function. We illustrate by applying the method to a recent study of in vitro fertilization carried out in North Carolina. The number of cells at transfer is evidently a marker for embryo viability.     

Ultrasound tracking of the movement of embryo-associated air bubbles on standing after transfer

The aim of this study was to investigate whether standing upright shortly after embryo transfer has any potential to affect the position of embryos transferred to the uterine cavity during treatment with in-vitro fertilization (IVF). This was assessed by ultrasound-guided tracking of embryo-associated air within the uterine cavity. A prospective study of 93 patients undergoing 101 consecutive embryo transfers in an IVF programme was carried out. Transvaginal ultrasound guided embryo transfer was performed with a second ultrasound in standing position immediately after transfer, allowing the movement of embryo-associated air to be assessed. No movement occurred in 94.1% (95/101) of transfers, movement of <1 cm in 4.0% (4/101) of transfers and movement of 1-5 cm in 2.0% (2/101) transfers. No movement of embryo-associated air out of the uterine cavity, either into the cervix or the intramural portion of the Fallopian tube, was seen. Standing shortly after embryo transfer does not play a significant role in the final position of embryo-associated air and is unlikely to be a factor in determining the position of embryos transferred to the uterine cavity during treatment with IVF.