P–794 Prevalence of positivity for SARS-CoV–2 RNA in follicular fluid in infertile patients

Study question

Is Sars-Cov–2 present in the follicular fluid of infertile patients?

Summary answer

In the experience of the Infertility and IVF Unit, University Of Bologna, Italy, RNA of SARS-Cov–2 was not detected in the follicular fluid.

What is known already

Data on the risk of virus presence in reproductive cells and transmissibility in IVF procedures are very limited. In literature only one study reports the detection of SARS-Cov–2 viral RNA in oocytes of PCR positive women. Research of RNA in follicular fluid could be a marker able to indicate whether to continue IVF treatments in the case of swab-positive patients.

Study design, size, duration

Prospective study performed at Infertility and IVF Unit, Sant’Orsola University Hospital, University of Bologna, Italy, from March 2020 to January 2021. 451 IVF cycles were performed on 902 patients. In addition 59 cycles of oocyte cryopreservation were also performed to fertility preservation in oncological patients. In all positive swab patients was analyzed the follicular fluid for RNA virus detection.

Participants/materials, setting, methods

961 patients underwent telephone triage before going to the IVF Center to identify subjects with suspected or confirmed infection. Body temperature was measured on all patients before entering the IVF Center.

All patients were subjected to real-time analysis (RT PCR) of pharyngeal swab samples 48 hours before transvaginal ultrasound-guided oocyte retrieval.

In case of positive swab, PCR was performed on follicular fluid.

Main results and the role of chance

In our population of infertile patients the incidence of SARS COV–2 infection positivity was 0.4% (4/961).

No IVF treatments were suspended. The oocytes of the 4 women with positive swab were cryopreserved using closed devices stored in a special dedicated cryogenic container. No viral RNA was detected in the follicular fluid.

Limitations, reasons for caution

there are no limitations to the study.

Wider implications of the findings: The absence of SARS-COV–2 RNA in the follicular fluid is a reassuring result in the storage and future use of oocytes.

Trial registration number

Not applicable

P–098 Use of Dimethylxanthine Theophylline in surgical retrieved sperms that do not recover motility after thawing

Study question

Can the use of Theophylline recover motility of frozen surgically retrieved sperms in case of absence of motility after thawing?

Summary answer

Theophylline allows to recover motility of thawed surgically retrieved sperms. The utilization of sperms with or without pharmacological activation gives comparable clinical outcomes.

What is known already

Testicular sperm motility is usually poor. A method is needed to detect viable sperm for ICSI when motility is totally absent after freezing/thawing. Hypo-osmotic swelling test, mechanical touch technique, laser-assisted immotile sperm selection, birefringence-polarization microscopy and exposure to pharmacological stimulation are techniques used for this purpose. Among pharmacological agents Dimethylxanthine Theophylline is a phosphodiesterase inibitor that improves sperm motility by promoting an increase in intracellular cyclic AMP levels. Few studies report that it is efficient for recovery of sperm motility in cases of thawed testicular and retrograde ejaculation samples improving reproductive outcomes.

Study design, size, duration

Retrospective analysis of sixty frozen surgical sperm cycles (45 patients) utilized from February 2018 to November 2020. After thawing, samples were divided in two Groups according to motility recovery. Group A: presence of motility, Group B: absence of motility. Group B was treated with Theophilline and motility was re-assessed after incubation. Activated sperms were utilized for ICSI when available. Sperm motility recovery, fertilization, pregnancy rate/transfer, implantation and miscarriage rate were evaluated in both Groups.

Participants/materials, setting, methods

Surgical specimens were treated and concentrated in SpermRinse™ Medium (Vitrolife) and then cryopreservated in nitrogen vapor in TEST Yolk Buffer (Irvine Scientific). After thawing, only samples with no motility recovery were treated with a brief incubation in Theophylline (GM501 SpermMobil, Gynemed) and washed in Polyvinylpyrrolidone (ICSITM Vitrolife) before injection. ICSI was performed in all cases approximately 4–5 hours after sperm thawing. After fertilization check, transfer was scheduled in day 2.

Main results and the role of chance

Women’s age Group A (34,39±2,29 M±SD) and group B (35,87±4,34 M±SD) and men’s age Group A (37,31±5,12 M±SD) and group B (40,89±8.15 M±SD) were not significantly different (P= .328 and P=.218) respectively.

Group A: 13/60 cycles (21.7%) (9 patients). Pre freezing and post thawing total motility percentage were 34.0±19.0 (M±SD) and 13.5±15.6 (M±SD) respectively (39.8% recovery). Group B: 47/60 cycles (78.3%) (36 patients). Pre freezing total motility percentage was 5.3±8.5 (M±SD) and no motility was recovered post thawing (0%). After treatment with Theophylline total motility was 1.8±1.8 (M±SD) (33.5% recovery). Motile sperms were utilized in all cases except from two in the Group B.

Number of injected oocytes was 2.8±1.1 (M±SD) in Group A and 4.3±3.1 (M±SD) in Group B (P=.004) respectively.

Fertilisation rate (63.1% and 45.4%, P=.066), Number of embryos transferred (1.8±0.7 M±SD and 1.6±0.7 M±SD, P=.271), Pregnancy rate/Transfer (54.5% and 37.1%, P=.502), Implantation rate (30.0% and 27.8%, P=.919) and Miscarriage rate (33.3% and 30.7%, P=.675) were not statistically significant between Group A and B respectively.

In the two cases of group B injected with immotile sperm, fertilization rate was 0% (0/3) and 50% (2/4).

Limitations, reasons for caution

A larger study is needed to investigate the recovery of sperms motility (and/or their activation) and clinical outcomes, in particular referring to the origin of sampling (epididymal aspirate and testicular tissue) and type of azoospermia (obstructive and non-obstructive).

Wider implications of the findings: Theophylline is an effective tool for sperm motility recovery after thawing allowing to inject viable sperm and facilitating laboratory handling.

Trial registration number

Not applicable

First polar body morphology before ICSI is not related to embryo quality or pregnancy rate

BACKGROUND

The aim of this study was to analyse the relationship between the first polar body (1st PB) morphology and the fertilization rate, cleavage rate, embryo quality, pregnancy and implantation rate.

METHODS

This was a retrospective study on 167 consecutive cycles undergoing assisted reproduction with ICSI. The 1st PB morphology was evaluated at the moment of ICSI in the 596 injected oocytes and it was coded as intact or fragmented. The fertilization rate, cleavage rate, embryo quality (three grades), pregnancy rate, implantation rate and the time elapsed between oocyte retrieval and ICSI were evaluated. The 1st PB morphology was checked twice (denudation and ICSI) in a random sample of 180 oocytes in order to verify the effect of the in vitro culture.

RESULTS

No significant relationship was found between the 1st PB morphology and the fertilization rate (P=0.703), cleavage rate (P=0.055), embryo quality (P=0.673), pregnancy rate (P=0.201) and implantation rate (P=0.511). A significant positive relationship (P=0.006) was found between the frequency of the 1st PB fragmentation and the time elapsed between denudation and ICSI. The pregnancy rate was significantly higher (P=0.008) when oocytes were injected between 5 and 7 h after retrieval rather than earlier or later.

CONCLUSIONS

Our data suggest that the embryo quality, pregnancy rate and implantation rate are not related to the 1st PB fragmentation. The time which elapses between the oocyte retrieval and ICSI should be maintained at approximately 6 h in order to obtain optimal results.

Micromanipulation of cryopreserved embryos and cryopreservation of micromanipulated embryos in PGD

The possibility to employ cryopreservation in Preimplantation Genetic Diagnosis (PGD) should enlarge the opportunities for research and clinical activity. For these purposes, we tried three kinds of approaches on human abnormal embryos: (1) cryopreservation of biopsied embryos; (2) biopsy of thawed embryos; and (3) biopsy of embryos derived from thawed oocytes. Our preliminary results show that: (1) biopsy of thawed embryos is feasible and FISH analysis is possible on both survived and lysed cells; (2) Optimization of freezing/thawing procedures are necessary to obtain better survival rate after thawing of biopsied embryos; (3) Biopsy and FISH are feasible on embryos derived from thawed oocytes and they could be a good way to study the chromosomal arrangement of these poorly investigated embryos.

Clinical experience and applications of oocyte cryopreservation

Oocyte cryopreservation is a viable solution for the ethical problems related to embryo storage, and the only available technique for preservation of fertility in women who have to undergo chemo- or radiotherapy. The main problems with oocyte cryopreservation are concerned with the survival rate and the fertilization rate. Recently the introduction of the intracytoplasmic sperm injection (ICSI) led to an increase in the fertilization rate. The success achieved with the first case treated encouraged us to set up a clinical trial on human oocyte cryopreservation. In the first stage of the study, 23 women with tubal infertility were enrolled. Superovulation was induced and 375 oocytes were retrieved; of these 338 oocytes were frozen. The survival rate was 59.5% and was independant of the duration of cryopreservation or the presence of cumulus. The normal fertilization rate was 64.4%, and only 7.5% of fertilizations were abnormal. A total of 90.8% of fertilized oocytes cleaved. A mean of 3.1+/-1.3 embryos per patient were transferred. Three pregnancies were achieved. In the second stage of our investigation, more patients were enrolled and similar results were observed. Sixteen pregnancies were achieved. A further stage of the investigation involved the fertilization of frozen oocytes with frozen sperm and even these resulted in a pregnancy. Our study demonstrated that pregnancies can also be achieved when frozen eggs are fertilized by testicular and epididymal sperm. As a consequence of the success of our investigations, a program of oocyte cryopreservation for oncological patients has been initiated in our centre. In our opinion, oocyte cryopreservation is, at present, a safe and efficient technique as documented by the birth of several healthy children.

Technical aspects of oocyte cryopreservation

Since the successful development in the mouse, the oocyte cryopreservation has been applied with varying success to a number of different species including the human. The recently reported successes in terms of pregnancies obtained by human oocyte cryopreservation are encouraging. Several studies typically reported different rates of survival (20-80%), fertilization (30-60%) and cleavage (32-100%). This variability of results throws some doubts on the usefulness of oocyte cryopreservation in IVF treatment cycles. It remains to be determined whether the relatively different success rates reported in literature, mainly in terms of survival rate, are due to methodological differences. We tried to investigate the effect of some factors on the oocyte survival rate after thawing: the presence or absence of cumulus oophorus and the exposure time of the oocytes to cryoprotectant. We suggest that a combination of several factors including both morphological and biophisical ones can affect the oocyte survival rate.

Ongoing pregnancy after intracytoplasmic injection of testicular spermatozoa into cryopreserved human oocytes

Human oocyte cryopreservation has met with limited success in terms of both survival and subsequent fertilization. We recently reported the first birth of a healthy female infant after intracytoplasmic sperm injection of cryopreserved oocytes. The current report describes the first pregnancy achieved after intracytoplasmic injection of testicular sperm into cryopreserved human oocytes.

Oocyte cryopreservation

Cryopreservation of human oocytes has been employed with little success in clinical practice, even though it may solve the legal and ethical problems linked to embryo freezing. Various attempts to cryopreserve human oocytes have mostly been unsuccessful, leading to low oocyte survival rates after thawing, and the search for an optimal protocol for oocyte cryopreservation remains elusive. A preliminary study was undertaken to evaluate some of the factors influencing the survival rate of human oocytes and the efficiency of intracytoplasmic sperm injection (ICSI) as an insemination procedure. A total of 38 women with tubal infertility were enrolled in the study. The cryopreservation procedure consisted of a slow freeze-rapid thawing technique using 1,2 propanediol and sucrose as cryoprotectants. The overall oocyte survival rate was approximately 60%. A better survival rate was obtained when the oocytes were cryopreserved in the presence of partially removed cumulus oophorus rather than in the presence of totally enzymatically removed cumulus oophorus. The cryoprotectant concentration and the equilibration time also appear to influence the oocyte survival rate. ICSI may be an efficient method of achieving a satisfactory outcome in terms of fertilization in cryopreserved human oocytes. Embryonic morphological quality does not seem to be compromised by cryopreservation. In conclusion, these data show that cryopreservation may ensure that the integrity of the human oocyte is adequate for normal fertilization and embryo development.

Birth of a healthy female after intracytoplasmic sperm injection of cryopreserved human oocytes

OBJECTIVE

To describe the first birth achieved after intracytoplasmic sperm injection (ICSI) of cryopreserved human oocytes.

DESIGN

Case report.

SETTING

University of Bologna Hospital, Department of Obstetrics and Gynecology, Reproductive Endocrinology Unit, IVF and Infertility Center.

PATIENT(S)

One patient undergoing IVF.

INTERVENTION(S)

Transvaginal ultrasound-guided oocyte retrieval followed by oocyte freezing. Artificial preparation of the endometrium with E2 and P, oocyte thawing, and ICSI.

RESULT(S)

Four of 12 cryopreserved oocytes survived; using ICSI, 2 underwent normal fertilization but only 1 cleaved. One good-quality 4-cell embryo was transferred. A single gestation was confirmed by ultrasound at the 7th week. Amniocentesis was performed at the 16th week and demonstrated a normal female karyotype of 46,XX. After a normal pregnancy, a healthy female infant was born at the 38th week of gestation.

CONCLUSION(S)

The combination of ICSI and oocyte cryopreservation is a new tool in assisted reproductive technology.

Transforming growth factor-beta 1 in the human endometrium

Transforming growth factor-beta 1 (TGF-beta 1) is a polypeptide involved in a variety of important physiological and pathophysiological processes such as the implantation of the embryo into the endometrium. Many factors seem to be related to this event. TGF-beta 1 is involved in many mechanisms both in endometrial and in embryonic tissues: it induces proliferation and differentiation, it regulates proteolytic activity and it modulates the maternal immune response. This study evaluated the presence of TGF-beta 1 in the endometrium during normal menstrual cycles and in the uterine fluids during induction of ovulation in the framework of an in vitro fertilization program. Immunohistochemistry was used to identify TGF-beta 1 in the endometrium and immunodot-blot to quantitate TGF-beta 1 in the uterine cavity fluid. The study shows that TGF-beta 1 is present in the endometrial tissue and its secretion is modulated during the menstrual cycle, as demonstrated immunohistochemically; its production seems to be controlled by ovarian steroids. In conclusion, TGF-beta 1 influences the growth and differentiation of the embryo, as well as the activation of embryonic proteolytic enzymes, and it modulates the maternal-embryonic immune response. Its variability in the uterine cavity is demonstrated in this study, and the underexpression of TGF-beta 1 in the uterine cavity might be responsible for failed implantation.

Factors regulating interaction between trophoblast and human endometrium

Implantation is a crucial step in human reproduction. Disturbances of this process are responsible for pregnancy failure after both in vivo and in vitro fertilization. The endometrium provides the implanting embryo with a unique substratum where the embryo communicates with biochemical signals, attaches itself, penetrates and grows without blood circulation. The highly proliferative phase of the cytotrophoblast, during early human embryogenesis, may be due to endogenous production of growth factors that may establish autocrine/short range paracrine stimulator loops which explain the tumor-like properties of these tissues. Endometrial BM penetration and stroma invasion may be due to the proteolytic capability of the human embryo. It is suggested that collagenase and the urokinase-like plasminogen activator are responsible for this activity. To clarify the molecular mechanisms involved in human embryo implantation several models are suggested: culture of blastocysts, culture of endometrial cells, and endometrial explant co-culture. Human blastocysts cultured with whole perfused human uteri make it possible to recognize some aspects of the entire implantation process and give us the possibility of improving the benefits provided by new technologies in reproductive medicine and reducing embryonic loss at an early stage.

Rapid and specific RIA of serum estrone sulfate with selective solid phase extraction

The methods commonly used to evaluate conjugated steroids require hydrolysis and chromatographic purification. To avoid these steps, a simple method involving selective solid phase extraction and RIA using a highly specific antiserum for estrone sulfate (E1S) has been evolved. A Bond-Elut C2 cartridge was used for solid phase extraction of estrone (E1) and E1S; recoveries were 80 and 90% respectively. The intra- and inter assay precision of the assay at 3 serum levels, were 6.5, 10.4 and 4.4 and 12.7, 13.9 and 7.4% respectively. Accuracy, tested by linearity and recovery tests, was acceptable. A good correlation exists between a conventional enzymatic method and the proposed method. The latter is less time consuming and more reliable, thus providing a rapid assay to evaluate E1 and E1S in the same serum sample.

Extraction of estrogens by human perfused uterus. Effects of membrane permeability and binding by serum proteins on differential influx into endometrium and myometrium

The present study was undertaken to examine the extractions of estradiol, estrone, and estrone sulfate from the circulation of the human perfused uterus. The differential permeability of endometrial and myometrial vascular beds to estrogens was evaluated in uteri samples obtained during the proliferative and secretive phases of the menstrual cycle. The effects of binding by human serum proteins on estrogen influx into the endometrium and myometrium were also determined by the use of double-isotope, single-injection, timed tissue sampling techniques adapted to the extracorporeal perfusion of human uterus. Tritiated test estrogen was injected into the uterine artery as a mixture with 14C-butanol, a free diffusible reference substance. The influx of 14C-dextran (a membrane-impermeable compound) was used to test the aspecific influx from vasculature to extravascular space. Results show that in the human perfused uterus: (1) membrane permeability plays different roles in estrogen influxes between the endometrium and myometrium; (2) during the proliferative and secretive phase of the menstrual cycle the uterine microvessels are differently permeable to the free plus protein-bound estrogens; and (3) plasma proteins decrease the endometrial and myometrial uptakes of estrogens.

Early human pregnancy in vitro utilizing an artificially perfused uterus

The penetration of luminal epithelium in the uterine cavity represents the crucial event that triggers the failure of embryo implant, thus limiting the possibility of fertility control. The purpose of our study was to implant a human blastocyst, cultured in vitro, into a human uterus extracorporeally perfused with an oxygenated medium. For this purpose, human blastocysts, collected from patients who underwent IVF program because of irreparable tubal infertility, were injected under the luminal epithelium of human perfused uteri. Light and electron microscopy showed that human blastocyst can successfully undergo the stage of implantation and trophoblastic invasion in 52 hours of extracorporeal perfusion.

A 48-hour preservation of an isolated human uterus: endometrial responses to sex steroids

Human uteri were perfused with Krebs-Ringer bicarbonate-glucose buffer with and without estrogens and progesterone for a period of up to 48 hours to preserve a viable organ, which was responsive to hormones. Flow rates of 12 to 35 ml/minute per artery were fully distributed into the organ, with pressure values ranging from 80 to 120 mm Hg. Arteriovenous gradients of oxygen and carbon dioxide tensions as well as the levels of lactate, lactic dehydrogenase, and creatine kinase released in the perfusate, indicators of tissue ischemia or cell necrosis, showed a good preservation of the organ for up to 48 hours. The light- and electron-microscopic examinations of endometrial and myometrial tissues taken before and during perfusion confirmed this result. The extracorporeal perfusion of uteri with buffer containing estrogens plus progesterone exhibited secretive modifications of the proliferative endometrium, thus suggesting the viability of the organ and its responsiveness to sex steroids.