Microbial flora of the cervix assessed at the time of embryo transfer adversely affects in vitro fertilization outcome

Assisted reproductive techniques

Assisted reproductive technologies (ART) encompass fertility treatments, which involve manipulations of both oocyte and sperm in vitro. This chapter provides a brief overview of ART, including indications for treatment, ovarian reserve testing, selection of controlled ovarian hyperstimulation (COH) protocols, laboratory techniques of ART including in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI), embryo transfer techniques, and luteal phase support. This chapter also discusses potential complications of ART, namely ovarian hyperstimulation syndrome (OHSS) and multiple gestations, and the perinatal outcomes of ART.

Microorganisms within human follicular fluid: effects on IVF

Our previous study reported microorganisms in human follicular fluid. The objective of this study was to test human follicular fluid for the presence of microorganisms and to correlate these findings with the in vitro fertilization (IVF) outcomes. In this study, 263 paired follicular fluids and vaginal swabs were collected from women undergoing IVF cycles, with various causes for infertility, and were cultured to detect microorganisms. The cause of infertility and the IVF outcomes for each woman were correlated with the microorganisms detected within follicular fluid collected at the time of trans-vaginal oocyte retrieval. Microorganisms isolated from follicular fluids were classified as: (1) ‘colonizers’ if microorganisms were detected within the follicular fluid, but not within the vaginal swab (at the time of oocyte retrieval); or (2) ‘contaminants’ if microorganisms detected in the vagina at the time of oocyte retrieval were also detected within the follicular fluid. The presence of Lactobacillus spp. in ovarian follicular fluids was associated with embryo maturation and transfer. This study revealed microorganisms in follicular fluid itself and that the presence of particular microorganisms has an adverse affect on IVF outcomes as seen by an overall decrease in embryo transfer rates and pregnancy rates in both fertile and infertile women, and live birth rates in women with idiopathic infertility. Follicular fluid microorganisms are a potential cause of adverse pregnancy outcomes in IVF in both infertile women and in fertile women with infertile male partners.

Antibiotics prior to embryo transfer in ART

BACKGROUND

Embryo transfer (ET) involves the placement of one or more embryos into the uterine cavity, usually by passing a catheter through the cervical os. ET is the final step in an assisted reproductive technology (ART) cycle, where a woman has undergone controlled ovarian stimulation, egg retrieval and in vitro fertilisation of her eggs. Despite the transfer of high quality embryos, many ETs do not result in a pregnancy. There are many factors which may affect the success of ET, including the presence of upper genital tract microbial colonisation. The administration of antibiotics prior to ET has been suggested as an intervention to reduce levels of microbial colonisation and hence improve pregnancy rates.

OBJECTIVES

To evaluate the effectiveness and safety of antibiotic administration prior to ET during ART cycles.

SEARCH METHODS

We searched the Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library, MEDLINE, Ovid MEDLINE® In-Process & Other Non-Indexed Citations, Ovid MEDLINE® Daily and Ovid MEDLINE® (from inception to February 2011), Ovid EMBASE (January 2010 to February 2011), Ovid PsycINFO, CINAHL, LILACS, trial registers for ongoing and registered trials, citation indexes, ClinicalStudyResults, PubMed, OpenSIGLE database and for for herbal and complimentary therapy protocols and reviews.

SELECTION CRITERIA

Only randomised controlled trials were included.

DATA COLLECTION AND ANALYSIS

The titles and abstracts of articles identified by the search were screened by one review author for eligibility. Two review authors then independently examined the full text articles for suitability for inclusion in the review. Data were extracted independently by two review authors.

MAIN RESULTS

We identified four potential studies, of which three were excluded.The included trial reported clinical pregnancy rates but not live births. There was no evidence of a difference in clinical pregnancy rate between those receiving an amoxycillin and clavulanic acid antibiotic combination (64/178: 36%) and those not (61/172: 35.5%) (OR1.02, 95% CI 0.66 to 1.58). Genital tract colonisation was significantly reduced in women receiving this antibiotic regimen (OR 0.59, 95% CI 0.37 to 0.95).

AUTHORS' CONCLUSIONS

This review suggests that the administration of amoxycillin and clavulanic acid prior to embryo transfer reduced upper genital tract microbial contamination but did not alter clinical pregnancy rates. The effect of this intervention on live birth is unknown. There are no data from randomised controlled trials to support or refute other antibiotic regimens in this setting.Future research is warranted to assess the efficacy of alternative antibiotic regimens. Researchers should assess live birth as the primary outcome and address quantitative microbial colonization as a secondary outcome.

The dynamics of the vaginal microbiome during infertility therapy with in vitro fertilization-embryo transfer

PURPOSE

To determine the vaginal microbiome in women undergoing IVF-ET and investigate correlations with clinical outcomes.

METHODS

Thirty patients had blood drawn for estradiol (E(2)) and progesterone (P(4)) at four time points during the IVF-ET cycle and at 4-6 weeks of gestation, if pregnant. Vaginal swabs were obtained in different hormonal milieu, and the vaginal microbiome determined by deep sequencing of the 16S ribosomal RNA gene.

RESULTS

The vaginal microbiome underwent a transition during therapy in some but not all patients. Novel bacteria were found in 33% of women tested during the treatment cycle, but not at 6-8 weeks of gestation. Diversity of species varied across different hormonal milieu, and on the day of embryo transfer correlated with outcome (live birth/no live birth). The species diversity index distinguished women who had a live birth from those who did not.

CONCLUSIONS

This metagenomics approach has enabled discovery of novel, previously unidentified bacterial species in the human vagina in different hormonal milieu and supports a shift in the vaginal microbiome during IVF-ET therapy using standard protocols. Furthermore, the data suggest that the vaginal microbiome on the day of embryo transfer affects pregnancy outcome.

Embryo transfer induces a subclinical endometritis in recipient mares which can be prevented by treatment with non-steroid anti-inflammatory drugs

We tested the hypothesis that subclinical endometritis occurs after embryo transfer (ET) in the horse. Recipient mares were treated with meclofenamic acid (M) or flunixin meglumin (F) after ET or were left untreated (n=9 per group). Embryos were re-collected 4 days after transfer. Endometrial biopsies were taken for histology and analysis of cyclooxygenase-2 (COX-2) by immunohistochemistry and for PCR. Bacteriological swabs were collected from the uterus and lavage fluid of donor and recipient mares. Progesterone and prostaglandin F(2alpha) release was analysed in recipient mares after ET. Four days after ET, four embryos were recovered from group M and three from group F and untreated mares, each. The number of polymorph nuclear neutrophils was reduced in treated mares (p<0.05). Expression of mRNA for inflammatory cytokines did not differ between groups. In group M, expression of endometrial prostaglandin-E-synthase was higher than in group F (p<0.05). Three out of nine control mares underwent preterm luteolysis (p<0.05 vs. treatment groups), prostaglandin release (p<0.05) and the number of COX-2 positive cells (p<0.01) were significantly higher than in treated mares. Only few bacteriological swabs were positive. In conclusion, treatment of embryo recipient mares with non-steroid anti-inflammatory drugs inhibits the inflammatory response of the endometrium after ET. Meclofenamic acid may have advantages in comparison to flunixin meglumin due to a different influence on prostaglandin synthesis that may not result in inhibition of embryonic mobility.

Relationship of cytopathology and cervical infection to outcome of in-vitro fertilization and embryo transfer

OBJECTIVE

To determine whether a relationship exists between in-vitro fertilization and embryo transfer (IVF-ET) outcome and cervical infection or presence of human papillomavirus (HPV).

METHOD

Cervical scrapes, digital colposcopies, and cervical biopsies were performed in 1044 Chinese women undergoing IVF for tubal infertility or, in their partners, abnormal semen. The pregnant (n=415) and nonpregnant (n=629) groups differed neither in clinical signs of cervical inflammation nor in rate of HPV detection.

RESULTS

There were no associations between IVF-ET outcome and infection rate, degree of cytopathologic abnormality, detection of HPV, or results of digital colposcopy and cervical biopsy. Cytologic results did not correlate with any of the clinical parameters of IVF-ET.

CONCLUSIONS

No association was found between IVF-ET outcome and cervical infection, cytopathologic result, HPV detection, or result from the colposcopy or biopsy. Extensive testing and treatment for cervical infection do not appear necessary in IVF-ET candidates.

Examination of bacterial contamination at the time of embryo transfer, and its impact on the IVF/pregnancy outcome

PURPOSE

This study was designed to examine the effect of bacterial contamination on in vitro fertilization treatment outcomes.

METHOD

In a prospective clinical trial, 152 patients aged 23-38 years, mean 33.3 +/- 4.6, undergoing IVF treatment were selected for this study. During embryo transfer, separate samples were collected for microbial examination from the following sites: the fundus of the vagina, the cervix, the embryo culture medium prior and post-embryo transfer, the tip of the catheter, and the external sheet. All the samples were separately cultured to identify any bacteria or yeast present.

RESULTS

Pregnancy rates in patients testing positive for Entrobacteriaceae (22.2% versus 51%) and Staphylococcus species (17.6% versus 44%) were significantly lower than those in the negative culture group (p < 0.001). The pregnancy rates do not seem to be affected by the other isolated microorganisms.

CONCLUSION

This study shows that the presence of vaginal-cervical microbial contamination at the time of embryo transfer is associated with significantly decreased pregnancy rates.

Fulminant Sepsis after Second-Trimester Amniocentesis in Pregnant Women by in vitro Fertilization and Embryo Transfer

Second-trimester amniocentesis is a common procedure for prenatal diagnosis. Sepsis is a rare complication after amniocentesis and may rapidly deteriorate if prompt treatment, including broad-spectrum antibiotics and removal of the infected abortus, is delayed. In vitro fertilization and embryo transfer (IVF-ET) is a standard final treatment for infertile women. Transvaginal oocyte retrieval is necessary for such women; this procedure potentially causes Escherichia coli attaching and effacing in the abdominal cavity. Here we report that two pregnant women by IVF-ET developed sepsis after second-trimester amniocentesis. The cause of sepsis after amniocentesis is still unknown. We provided the possibility of the causation of the E. coli infection associated with the previous intra-abdominal procedure, but it needs more evidence to prove it.

Removal of cervical mucus prior to embryo transfer improves pregnancy rates in women undergoing assisted reproduction

The removal of cervical mucus during embryo transfer has been postulated to increase the pregnancy and implantation rates by not interfering with embryo implantation. Even so, this is a time-consuming procedure that may increase the incidence of difficult transfers by removing the naturally lubricant mucus. In addition, any cervical manipulations at the time of embryo transfer may cause unwarranted uterine contractions. In this prospective, controlled study, 286 women undergoing embryo transfer between January and May 2006 were divided into two groups according to whether the cervical mucus was scheduled to be aspirated (group A) or not (group B). The two groups were similar with regards to the demographics, cause of infertility, characteristics of ovarian stimulation and embryos transferred. Even so, the clinical pregnancy rate was significantly higher in group (A) than group (B) (OR = 2.18, 95% CI = 1.32-3.58), although there were easier transfers in group (B) than group (A) (OR = 3.00, 95% CI = 1.05-8.55). This demonstrates that even though embryo transfers were easier to perform when the cervical mucus was left in place, aspiration resulted in an increased chance of clinical pregnancy.

Oxytocin does not contribute to the effects of cervical dilation on progesterone secretion and embryonic development in mares

The aim of the present study was, to investigate the effects of oxytocin administration on Day 7 post-ovulation on progesterone secretion, pregnancy rate and embryonic growth in mares. Endogenous stimulation of oxytocin release was compared to the administration of native oxytocin or the long-acting oxytocin analogue carbetocin. At Day 7 after ovulation, mares had to undergo four treatments in a crossover design: (a) control, (b) oxytocin (10 IU i.v.), (c) carbetocin (280 microg i.m.) and (d) cervical dilation. On Day 13, all mares (8 of 8 mares) were pregnant on groups control, oxytocin and carbetocin and only 6 of 8 mares on group dilation. In one mare uterine fluid accumulation and uterine edema from Day 6 to 13 and early embryonic death by Day 11 occurred during dilation treatment. Another mare, which did not become pregnant during dilation treatment, developed uterine fluid accumulation and uterine edema from Day 10 to 14. Mean growth rates of the conceptuses did not differ among treatment groups and individual growth rates varied in a wide range from -0.1 to 0.8 cm per day. At Day 13, mean diameters of conceptuses yielded 1.4+/-0.1 cm in control group, 1.5+/-0.1 in oxytocin and carbetocin group and 1.3+/-0.2 cm in dilation group. Secretion of progesterone was not affected by treatments. Administration of oxytocin and carbetocin caused similar maximum plasma concentrations of oxytocin, but onset and duration of peaks differed. Maximum concentrations after intramuscular application of carbetocin were obtained almost 20 min later when compared to intravenous administration of oxytocin. Duration of peaks after injection of the long-acting oxytocin analogue was more than three-fold longer than after administration of native oxytocin. In conclusion, the present study showed that single administration of oxytocin or its long-acting analogue carbetocin at Day 7 after ovulation did not affect progesterone secretion, pregnancy rate and embryonic growth. Two possible scenarios concerning the effects of cervical dilation were observed: In the majority of mares, dilation of the caudal half to two-third of the cervical lumen up to a diameter of 4.5 cm had no negative consequences on progesterone secretion and pregnancy outcome. However, cervical dilation caused uterine inflammation and subsequent luteolysis in two mares and early embryonic death in one of them. Thus, manipulation of the cervix itself seems not to have negative impact on success rates of transcervical transfer of embryos in the mare.

Prevention of iatrogenic pelvic infection during in vitro fertilization--current practice in the UK

Uterine instrumentation can provoke pelvic inflammatory disease in women infected with Chlamydia trachomatis. During an IVF treatment cycle, a fine plastic catheter is passed into the endometrial cavity to transfer the embryos. The objective of this survey was to find out what measures are being taken by IVF clinics to prevent ascending infection. Postal questionnaires were sent to 75 clinics in the UK, asking about their sexually transmitted infection screening policies and their protocols on antibiotic prophylaxis. Seventy clinics (93%) responded, of which 37 (53%) neither screen the female partner for C. trachomatis, nor give appropriate antibiotic prophylaxis. Approximately half of UK IVF clinics make no attempt to either detect or treat chlamydial infection prior to embryo transfer. More research is required to evaluate whether embryo transfer does pose a significant risk factor for pelvic inflammatory disease.

Recurrent implantation failure in assisted reproduction: how to counsel and manage. B. Treatment options that have not been proven to benefit the couple

The success of assisted reproduction, although gradually increasing over the years, is still less than satisfactory. Many couples have benefited from this treatment; however, many have also been left frustrated following multiple failed attempts. Couples who fail to conceive after multiple IVF/intracytoplasmic sperm injection (ICSI) treatments often seek treatment options that are new and that have not been offered before. Some of these include immunological testing and treatment, allogenic lymphocyte therapy, intratubal transfer of zygotes and embryos, blastocyst transfer, sequential embryo transfer, assisted hatching, co-cultures, and preimplantation genetic screening for aneuploidy. Although the evidence behind some of these is more robust, most suffer from lack of well designed randomized trials comparing them with other treatment options. Randomized studies are extremely difficult to conduct, as couples will resist being randomized into a treatment group where previously failed procedures will be repeated. In the mean time, assisted reproduction programmes should resist offering treatment options that are not evidence based, or at least they should share with the couple the information that is available and should stress that none of these is a panacea for their problem.

Does intravaginal probiotic supplementation increase the pregnancy rate in IVF–embryo transfer cycles?

This study investigated the effect of intravaginal administration of probiotics immediately after oocyte retrieval on vaginal colonization and outcome of the IVF-embryo transfer cycle. One hundred and seventeen women who underwent ovarian stimulation and IVF were randomized immediately after oocyte retrieval into two groups: those who received intravaginal probiotics (study group, n = 50) and those who did not (control group, n = 67). Vaginal colonization with lactobacilli and pregnancy rate were compared between the two groups. No significant between-group differences were observed in patient age, oestrogen and progesterone concentrations on day of human chorionic gonadotrophin administration, number of oocytes retrieved, fertilization rate, number of embryos transferred, or pregnancy rate. The presence of lactobacilli in the vagina during oocyte retrieval or embryo transfer did not improve the pregnancy rate. Furthermore, intravaginal administration of lactobacilli following oocyte retrieval did not affect the prevalence of lactobacilli during embryo transfer, or the pregnancy rate. Intravaginal probiotic supplementation immediately after oocyte retrieval has no effect on vaginal colonization or pregnancy rate in IVF cycles.

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.

L’antibiothérapie prophylactique (amoxicilline + acide clavulanique) avant transfert pour fécondation in vitro est inutile

OBJECTIVES

We studied the implantation rate during IVF cycles according to the prescription or not of antibiotics.

MATERIALS AND METHODS

During a 5-month period all the patients aged less than 38 years were randomized into two groups according to an independent personal variable. In group 1 amoxicilline + clavulanic acid 1g/125 mg were administrated from the ovum pick-up day for 6 days. In the group 2 no antibiotic treatment was administered.

RESULTS

The two groups were identical for all the criteria (type of stimulation, IVF/ICSI report, indications, average age). The average number of collected oocytes, obtained embryos and transferred embryos was similar in the two groups. The implantation rate per transfer was similar in the two groups (36.9% versus 36.5%; p>0.95). The pregnancy loss rate (biological pregnancy, early and late miscarriages or extra uterine pregnancy) was increased in a non significant manner (p=0.15) in the group with antibiotic: 33.3% (16/48) versus 20.8% (11/53) in the group without antibiotic.

CONCLUSION

This prospective randomised study leads us not to recommend this antibiotic prescription at the time of the embryo transfer during in vitro fertilisation attempt.

Colonisation bactérienne vaginale anormale et implantation en assistance médicale à la procréation

OBJECTIVE

To evaluate the efficiency of our treatment of vaginal infection for couples included in an IVF program.

PATIENTS AND METHODS

Microbiologic screening of vaginal flora and semen has been performed one month prior to in vitro fertilization for 951 couples in 2000. Antibiotic treatment was prescribed in case of positive culture.

RESULTS

Positive microbial growths were observed from endocervical and vaginal cultures in 218 women (22.9%). The clinical pregnancy rate was 30.29% in the group of patients without growth and 30.27% in the group with positive microbial growth. The implantation rate was significantly diminished in case of bacterial growth: 14.6 compared to 19.3% (P <0.02) for sterile endocervical culture. Five main bacterial species were found at the cervical level: Candida albicans (69 cases), Ureaplasma urealyticum (49 cases), Gardnerella vaginalis (43 cases), Streptococcus B or D (24 cases) and Escherichia coli (22 cases). Positive cultures from both vagina and semen were observed for 77 couples whose clinical pregnancy rate was 19.5 vs 36.2% in case of vaginal infection alone (P <0.01) with a spontaneous miscarriage rate of 46.7 compared to 17.6% (P <0.01).

DISCUSSION AND CONCLUSION

Endocervical microorganisms, even treated with adapted antibiotics, may affect embryonic implantation. Positive culture from both female and male partner may enhance this negative effect. In this case, the best strategy would be to cancel the IVF treatment.

Uterine cavity findings and hysteroscopic interventions in patients undergoing in vitro fertilization–embryo transfer who repeatedly cannot conceive

OBJECTIVE

To assess hysteroscopic findings in patients undergoing IVF-ET who repeatedly failed to conceive despite transfer of good-quality embryos.

DESIGN

Prospective, observational study.

SETTING

Clinical research unit for reproductive medicine in a private clinic.

PATIENT(S)

Fifty-five patients with a normal uterine cavity on hysterosalpingography before the initial IVF-ET cycle and two previous failed IVF-ET attempts despite transfer of a minimum of two good-quality embryos on each occasion.

INTERVENTION(S)

Standard transvaginal ultrasonography and diagnostic and therapeutic hysteroscopy.

MAIN OUTCOME MEASURE(S)

Endometrial findings on transvaginal ultrasonography and hysteroscopy and outcome of the cycles after surgical hysteroscopy and antibiotic therapy.

RESULT(S)

Twenty-five (45%) patients had abnormal endometrial findings and underwent treatment to correct the lesions. All patients underwent a third IVF-ET cycle. Pregnancy (50% vs. 20%) and implantation (19% vs. 5.5%) rates were significantly higher in patients who were treated for uterine abnormalities than in patients who had normal uterine cavities on hysteroscopy.

CONCLUSION(S)

The incidence of pathologic findings on hysteroscopy is high in patients with repeated failures of IVF-ET. Evaluation of endometrial integrity by hysteroscopy is highly valuable and should be applied to all such cases.

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.

Comparison of transfers to Fallopian tubes or uterus after ICSI

The aim of this study was to compare the implantation rate of tubal-replaced microinjected oocytes (MIFT) versus conventional day 2 intrauterine embryo transfer in patients undergoing intracytoplasmic sperm injection (ICSI). Sixty-three patients in need of ICSI, between 18 and 37 years of age with normal menstrual cycles and fewer than four previous ICSI attempts, were randomized between April 1999 and December 2001. In the MIFT group, up to three micro-injected oocytes were transferred laparoscopically 4 h after microinjection. In the ICSI-embryo transfer group, up to three cleaving embryos were replaced into the uterine cavity 48 h after insemination. Fifty-nine patients reached the stage of oocyte retrieval; 31 patients had a day 2 embryo transfer and 28 patients had MIFT. The ongoing clinical pregnancy and implantation rate (i.e. the total number of gestational sacs with fetal heartbeat divided by the total number of transferred embryos or micro-injected oocytes) was 35 and 24% in the ICSI-embryo transfer group and 29 and 11% in the MIFT group respectively. In conclusion, this study shows a significant decrease in implantation rate in the MIFT group (P < 0.05). In this group of patients there seems to be no advantage to tubal replacement of micro-injected oocytes.

[Difficult embryo transfer: what can be done in practice?]

Embryo transfer is an important step in the success of IVF treatment. One must avoid, at all cost, difficult transfers provoking bleeding, uterine contractions, and the retention of the embryo in the cervix, or even, its expulsion. Evaluation before IVF treatment, including a trial transfer, should allow one to evaluate the transfer step, anticipate problems, and thus improve treatment. The difficult insertion into the womb is most often associated with the presence of curves, which can be easily overcome by using pre-curved catheters.

Relationship of vaginal bacteria and inflammation with conception and early pregnancy loss following in-vitro fertilization

OBJECTIVE

The aim of this study was investigate the impact of vaginal flora and vaginal inflammation on conception and early pregnancy loss following in-vitro fertilization (IVF).

METHODS

We enrolled 91 women who were undergoing IVF. At embryo transfer (ET), all of the women had quantitative vaginal culture, ET catheter-tip culture, and vaginal Gram stain scored for bacterial vaginosis and quantitated for polymorphonuclear leukocytes (PMNs). Conception and early pregnancy loss were compared with culture and Gram stain results. Statistical analyses included the Chi-square test, Fisher's exact test and the Mann-Whitney U-test.

RESULTS

The overall live birth rate (LBR) was 30% (27/91), and the rate of early pregnancy loss was 34% (14/41). In women with bacterial vaginosis, intermediate flora and normal flora, the conception rates were 30% (3/10), 39% (12/31) and 52% (26/50), respectively (p = 0.06 for trend). Early pregnancy loss occurred in 33% (1/3), 42% (5/12) and 31% (8/26) of women, respectively (p = 0.06, comparing intermediate and normal flora). The vaginal log concentration of hydrogen peroxide-producing lactobacilli was 7.3 +/- 1.7 in women with a live birth (n = 27) and 4.9 +/- 2.5 in those with early pregnancy loss (n = 14) (p = 0.1).

CONCLUSIONS

IVF patients with bacterial vaginosis and with a decreased vaginal log concentration of hydrogen peroxide-producing lactobacilli may have decreased conception rates and increased rates of early pregnancy loss. A larger prospective treatment trial designed to evaluate the impact on IVF outcomes of optimizing the vaginal flora prior to IVF may be warranted.

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.

Prospective evaluation of blastocyst stage transfer vs. zygote intrafallopian tube transfer in patients with repeated implantation failure

OBJECTIVE

To compare extended culture with blastocyst stage transfer and zygote intrafallopian transfer (ZIFT) in the management of IVF patients with repeated implantation failure.

DESIGN

Prospective, nonrandomized study.

SETTING

An IVF unit at a university hospital.

PATIENT(S)

Sixty-four infertile patients with more than three previous failed IVF-ET attempts.

INTERVENTION(S)

Patients were allocated to undergo either blastocyst stage transfer (Group 1; n = 32) or ZIFT (Group 2; n = 32).

MAIN OUTCOME MEASURE(S)

Implantation, clinical pregnancy, and live birth rates.

RESULT(S)

Patient characteristics and response to stimulation were comparable for both groups. Totals of 84.3% and 97% of the patients underwent blastocyst transfer and ZIFT, respectively. Significantly more embryos were transferred through ZIFT (5.5+/-0.8) as compared with blastocyst transfer (2.3+/-1.4), and there were significantly more cycles with embryo cryopreservation in the ZIFT group as compared to the blastocyst transfer group (15/32 vs. 4/32, respectively). Implantation rate (13.6% vs. 1.4%), clinical pregnancy rate (40.6% vs. 3.1%), and live birth rates (38.7% vs. 0%) were all significantly higher in the ZIFT group as compared to the blastocyst transfer group, respectively.

CONCLUSION(S)

Zygote intrafallopian transfer is a powerful clinical tool in the management of patients with RIF. In contrast, blastocyst stage transfer fails to improve the outcome in this poor-prognosis group. The pathophysiology of RIF should be the subject of intense investigation to allow the introduction of appropriate therapeutic measures earlier in the course of treatment.

Ascorbic acid supplement during luteal phase in IVF

PURPOSE

To evaluate the impact of ascorbic acid of different doses as additional support during luteal phase in infertility treatment by means of a prospective, randomized, placebo-controlled, group comparative, double-blind study.

METHODS

Voluntary daily oral intake of either ascorbic acid (1, 5, or 10 g/day) or Placebo for 14 days after follicle aspiration for IVF-ET procedure. Data was obtained on 620 cases of women, age <40 years, undergoing first IVF-embryo transfer cycles in two private outpatient infertility clinics. All women were stimulated by the same protocol. The mean age was 31.73 (+/- 4.4 SD) years.

RESULTS

No differences in clinical pregnancy rate and implantation rate were noted in statistical logistic regression analysis between the four intake groups.

CONCLUSIONS

There was no clinical evidence of any beneficial effect, as defined by main outcome measures, of ascorbic acid on IVF-ET. Our data suggest there is no obvious value of high dosed intake of vitamin C during luteal phase in infertility treatment.

A prospective randomized comparison of the Wallace catheter and the Cook Echo-Tip catheter for ultrasound-guided embryo transfer

OBJECTIVES

To compare the performance of a new coaxial catheter system with an echo-dense tip (Cook Echo-Tip catheter) with a Wallace catheter during ultrasound-guided ET.

DESIGN

Prospective, randomized study.

SETTING

Private academically affiliated infertility center.

PATIENT(S)

Two hundred fifty-one patients undergoing IVF-ET.

INTERVENTION(S)

The patients underwent ultrasound-guided ET by a single physician with a standardized technique alternately using one of the two catheters.

MAIN OUTCOME MEASURE(S)

Implantation rates, pregnancy rates, ease of transfer, visualization, and status of catheter tip.

RESULT(S)

The echo-dense tip of the Cook Echo-Tip catheter was consistently seen with ultrasound guidance, minimizing the need for catheter movement to identify the tip. Implantation rate (30% vs. 35%), clinical pregnancy rate (57% vs. 55%), and ongoing pregnancy rate (49% vs. 47%) were similar in both groups.

CONCLUSION(S)

The Cook Echo-Tip catheter with its echogenic tip simplifies ultrasound-guided ET, but pregnancy success rates are similar to those obtained when a Wallace catheter is used.

Embryo transfer: techniques and variables affecting success

OBJECTIVE

To review the literature on the variables affecting embryo transfer success or failure and to define technical factors associated with optimal outcome.

DESIGN

Literature review.

RESULTS

Avoidance of blood, mucus, bacterial contamination, excessive uterine contractions, and trauma to the endometrium is associated with optimal pregnancy and implantation rates after transcervical embryo transfer. A trial transfer, ultrasonographic guidance, and use of "soft" catheters appear to facilitate successful embryo transfer.

CONCLUSION

An understanding of the variables associated with embryo transfer success together with adherence to techniques shown to facilitate atraumatic embryo transfer will enhance the efficiency of IVF by maximizing embryo implantation.

Bacteria in the transfer catheter tip influence the live-birth rate after in vitro fertilization

OBJECTIVE

To assess the impact of individual bacteria isolated from the vagina and tip of the embryo transfer catheter on live-birth rates.

DESIGN

Prospective clinical study.

SETTING

Infertility outpatient clinic of a university hospital.

PATIENT(S)

Ninety-one women undergoing IVF-ET.

INTERVENTION(S)

Cultures were obtained from the vagina for aerobic and anaerobic bacteria at the time of both sonographic egg retrieval and embryo transfer and from the tip of the embryo transfer catheter. Doxycycline treatment was started after egg retrieval.

MAIN OUTCOME MEASURE(S)

The live birth of one or more neonates.

RESULT(S)

Doxycycline had no substantial impact on the recovery of individual vaginal bacteria or on bacterial vaginosis. An increase in live-birth rate was associated with the recovery of hydrogen peroxide-producing Lactobacillus from the vagina (P=0.01) and from the embryo transfer catheter (P=0.01). In contrast, a reduction in live-birth rate was associated with recovery of Streptococcus viridans (S. viridans) from the embryo transfer catheter tip (P=0.04).

CONCLUSION(S)

In the setting of IVF-ET, prophylactic doxycycline had little effect on vaginal bacteria. Specific bacteria recovered from the embryo transfer catheter appear associated with a detrimental or beneficial effect or with no effect on live-birth rates.

The effect of intercourse on pregnancy rates during assisted human reproduction

Intercourse during an IVF cycle has the potential to improve pregnancy rates since exposure to semen is reported to promote embryo development and implantation in animals. Conversely, coitus-induced uterine contractions or introduction of infection may have a detrimental effect. A multicentre prospective randomized control trial was conducted to determine if intercourse during the peri-transfer period of an IVF cycle has any influence on pregnancy success. Participants undergoing thawed embryo transfer (Australian centre) or fresh embryo transfers (Spanish centres) were randomized either to abstain or to engage in vaginal intercourse around the time of embryo transfer. The transfer of 1343 embryos during 478 cycles of IVF resulted in 107 pregnancies (22.4%), with 125 viable embryos remaining by 6-8 weeks gestation. There was no significant difference between the intercourse and abstain groups in relation to the pregnancy rate (23.6 and 21.2% respectively), but the proportion of transferred embryos that were viable at 6-8 weeks was significantly higher in women exposed to semen compared to those who abstained (11.01 versus 7.69 viable embryos per 100 transferred embryos, P = 0.036, odds ratio 1.48, 95% confidence interval 1.01-2.19). Hence exposure to semen around the time of embryo transfer increases the likelihood of successful early embryo implantation and development.

Prophylactic antibiotics and endocervical microbial inoculation of the endometrium at embryo transfer

Prophylactic antibiotics administered routinely to women at the time of oocyte retrieval were associated with a reduction in positive microbiology cultures of embryo catheter tips 48 h later in 78.4% of patients. The implantation and clinical pregnancy rates were significantly lower (9.3% vs 21.6%, p<0.001; 18.7% vs 41.3%, p<0.01) in the women with positive microbial catheter-tip cultures.