Effect of aspiration vacuum on the developmental competence of immature human oocytes retrieved using a 20-gauge needle

Association between oocyte retrieval technique and number of oocytes retrieved

PURPOSE

To assess if there is an optimal oocyte retrieval (OR) technique to retrieve a maximum number of oocytes and mature oocytes (MII).

METHODS

Retrospective cohort study in which nine physicians completed a survey on OR techniques. Number of oocytes/follicle cohort, MIIs/follicle cohort, and MIIs/oocytes retrieved (%MII) were assessed for each technique for patients undergoing OR from 3/2013 to 7/2019. Data were stratified by number of follicles on ultrasound on day of trigger (< 6, 6-10, > 10).

RESULTS

Patient demographics were equivalent between techniques. For < 6 follicles, three techniques resulted in significantly fewer oocyte/follicle (0.97 ± 0.48, 0.95 ± 0.66, and 0.90 ± 0.41) compared to the top-performing technique (TPT) (1.11 ± 0.55). For 6-10 follicles, two techniques resulted in significantly fewer oocyte/follicle (0.95 ± 0.39 and 0.93 ± 0.35) compared to the TPT (1.06 ± 0.42). A different technique had higher %MII (0.77 ± 0.19) compared to two techniques (0.74 ± 0.21 and 0.72 ± 0.22). For > 10 follicles, two techniques resulted in significantly fewer oocyte/follicle (1.01 ± 0.42 and 1.07 ± 0.40) compared to the TPT (1.15 ± 0.41). These two techniques also resulted in fewer MII/follicle (0.75 ± 0.33 and 0.81 ± 0.34 vs. 0.87 ± 0.34). There was no consistent TPT across follicle number groups or for all outcome variables.

CONCLUSIONS

There does not appear to be a clear TPT, even for patients with few follicles. Providers who perform OR in a similar fashion to physicians at our institution should feel confident that those techniques obtain equivalent oocyte yields.

Factors Influencing the In Vitro Maturation (IVM) of Human Oocyte

In vitro maturation (IVM) of oocytes is a promising assisted reproductive technology (ART) deemed as a simple and safe procedure. It is mainly used in patients with impaired oocyte maturation and in fertility preservation for women facing the risk of losing fertility. However, to date, it is still not widely used in clinical practice because of its underperformance. The influencing factors, such as biphasic IVM system, culture medium, and the supplementation, have a marked effect on the outcomes of oocyte IVM. However, the role of different culture media, supplements, and follicular priming regimens in oocyte IVM have yet to be fully clarified and deserve further investigation.

In vitro maturation: a committee opinion

The results of in vitro maturation (IVM) investigations suggest the potential for wider clinical application. This document discusses the efficacy of IVM as reported in the published literature to date. This document replaces the document of the same name, last published in 2013.

Oocyte in vitro maturation: A sytematic review

In vitro maturation (IVM) is one of the most controversial aspects of assisted reproductive technology. Although it has been studied extensively, it is still not a conventional treatment option and is accepted as an alternative treatment. However, studies have shown that IVM can be used in almost all areas where in vitro fertilization (IVF) is used and it has a strong place in fertility protection and Ovarian Hyperstimulation syndrome management. The aim of this systematic review was to address all aspects of the current knowledge of IVM treatment together with the evolution of IVM and IVF.

Dynamic changes in mitochondrial distribution in human oocytes during meiotic maturation

PURPOSE

The change of mitochondrial distribution in human oocytes during meiotic maturation was assessed using 223 human oocytes donated from patients undergoing fertility treatment between June 2013 and February 2016.

METHODS

Live cell images of fluorescence-labelled mitochondria in human oocytes were analysed to investigate dynamic changes in mitochondrial distribution during meiotic maturation using a confocal microscope combined with an incubator in the presence or absence of colchicine and cytochalasin B, inhibitors for tubulin and actin filament, respectively. Subcellular distribution of mitochondria in human oocytes was also assessed at various stages using a transmission electron microscope (TEM).

RESULTS

Live cell imaging analysis revealed that the mitochondria-occupied cytoplasmic area decreased from 83 to 77 % of the total cytoplasmic area around 6 h before germinal vesicle breakdown (GVBD) and that mitochondria accumulated preferentially close to the perinuclear region. Then, the mitochondria-distributed area rapidly increased to 85 % of total cytoplasm at the time of GVBD. On the other hand, there was no significant change in mitochondrial distribution before and after polar body extrusion. Such changes in mitochondrial localization were affected differently by colchicine and cytochalasin B. Most of mitochondria in the cytoplasm formed cluster-like aggregates before GVBD while they distributed homogeneously after GVBD.

CONCLUSIONS

Most mitochondria localized predominantly in the non-cortical region of the cytoplasm of GV stage-oocytes, while the mitochondria-occupied area decreased transiently before GVBD and increased rapidly to occupy the entire area of the cytoplasm at GVBD by some cytoskeleton-dependent mechanism.

Oocyte retrieval at 140-mmHg negative aspiration pressure: A promising alternative to flushing and aspiration in assisted reproduction in women with low ovarian reserve

BACKGROUND:

Oocyte retrieval in women with low ovarian reserve is challenging and often results in poor pregnancy outcomes.

AIM:

The aim was to compare outcomes of oocyte retrieval using three aspiration methods in women with normal and low antral follicle counts (AFCs).

STUDY DESIGN:

Retrospective cohort study.

SETTING:

Tertiary care hospital.

MATERIALS AND METHODS:

Data from 172 women who underwent in-vitro fertilization/intracytoplasmic sperm injection over 3 years was studied after dividing into three groups: Group A (96) - normal AFC (≥10), direct oocyte retrieval at 120 mmHg, Group B (41) - low AFC (<10), direct retrieval at 140-mmHg, Group C (35) - low AFC, follicular flushing, and aspiration at 120-mmHg. In each group, oocyte yield, embryo quality, and pregnancy out comes were assessed.

RESULTS:

The oocyte and embryo yield in Groups A and B were comparable (P > 0.05) but were significantly less in Group C (P < 0.05). The pregnancy rates in Groups A and B were similar (35.4%, 39%) but were significantly less (17.1%) in Group C (P < 0.05). The live birth rate was 76% in Group A, 69% in Group B, and 50% in Group C. The miscarriage rates in the three groups were 21%, 31%, and 50%, respectively.

CONCLUSION:

Direct oocyte retrieval with 140-mmHg showed significantly better oocyte yield and pregnancy outcomes compared to flushing and aspiration in women with low AFC.

Approaches to oocyte retrieval for advanced reproductive technology cycles planning to utilize in vitro maturation: a review of the many choices to be made

PURPOSE

To evaluate the minutiae associated with oocyte retrieval for use in human in vitro maturation IVF cycles. Many of the relevant features of oocyte retrieval were identified by the Trounson group in the first publication on successful in vitro maturation using transvaginal oocyte harvesting and these were a major focus of this review.

METHODS

Published human and animal studies, together with topics from mathematics and mechanics, were used to try to understand the importance of different choices that could be made in structuring a transvaginal oocyte retrieval procedure in humans.

RESULTS

The published literature suggests that the highest oocyte recovery rate occurs using higher pressures and thicker needles, but this comes at the cost of damaging the cumulus oocyte complex. It is likely that this damage is caused by the sheer stress forces exerted on the cumulus oocyte complex due to parabolic forces associated with laminar flow within the needle and is likely worsened by irregular forces during intervals of turbulent flow occurring with entry into the needle. Larger needles also cause more pain and may be associated with more blood loss. Higher velocity entry into the follicle, needle rotation to prevent premature blockage of the lumen, and carefully timed applications of aspiration pressure theoretically optimize oocyte retrieval technique.

CONCLUSIONS

Oocyte retrieval for in vitro maturation is effected by the interaction of the many choices that need to be made in planning for the procedure. The most difficult decision involves aspiration pressure or fluid flow rate and needle size.

Developmental competence of human embryos derived from in vitro maturation of immature oocytes retrieved during cesarean section

AIM

To investigate the developmental competence of human embryos that originated from in vitro matured oocytes retrieved during cesarean section.

METHODS

Immature oocytes were collected from 95 pregnant women, who underwent cesarean section at Buddhachinaraj Hospital Medical School and consented to participate in the study. Retrieved oocytes were cultured in blastocyst medium supplemented with 75 IU/L of human menopausal gonadotropin. Oocyte maturation was assessed at 30 and 48 h after culture. In vitro matured oocytes were inseminated by intracytoplasmic sperm injection and cultured up to 144 h. The fertilization, cleavage and blastocyst formation rates were observed.

RESULTS

Maturation rate of oocytes after 30 h of culture was 67.9% compared with 13.1% at 48 h (P < 0.0001). Insemination of oocytes in both groups resulted in similar fertilization, cleavage and blastocyst formation rates.

CONCLUSION

A large proportion of oocytes retrieved at the time of cesarean section exhibited the capacity to undergo maturation in vitro. They can be fertilized and developed into good-quality blastocyst stage.

Effect of hCG priming on embryonic development of immature oocytes collected from unstimulated women with polycystic ovarian syndrome

BACKGROUND

The effect of hCG priming on oocyte maturation and subsequently outcome in IVM cycles has remained a debated issue. A randomized controlled study was performed to investigate whether or not hCG priming prior to oocyte aspiration can improve the developmental competence of immature oocytes from unstimulated ovaries in women with polycystic ovarian syndrome (PCOS).

METHODS

Eighty two patients with PCOS underwent IVM cycles. Each patient was randomly assigned to the hCG-primed (10,000 IU) or non-primed groups 36-38 hours before oocyte retrieval depending on the computerized random table. After the oocytes had in vitro matured, fertilization, culture and embryo transfer were performed.

RESULTS

The average number of cumulus-oocyte complexes (COCs) recovered was 13.80 and 14.35 in the hCG-primed and non-primed groups, respectively (p>0.05). The maturation rate of COCs was significantly improved in the hCG-primed group (55.43% vs. 42.29%; p<0.05). The fertilization and cleavage rates were comparable between the groups. The hCG-primed and non-primed groups did not differ with respect to the clinical pregnancy (37.50% vs. 50.00%), live birth (22.50% vs. 30.95%), and implantation rates (32.86% vs. 32.56%). The pregnancy losses was 6 (40.00%) of 15 clinical pregnancies in the hCG-primed group, and 8 (38.10%) of 21 clinical pregnancies in the non-primed group.

CONCLUSIONS

While a significant improvement in the nuclear maturation rate of immature oocytes was observed in hCG-primed IVM cycles with PCOS patients, the use of hCG prior to oocyte retrieval did not improve the subsequent embryo developmental competence. The high rate of pregnancy loss in IVM cycles should receive more attention.

Retrieval of rhesus monkey (Macaca mulatta) oocytes by ultrasound-guided needle aspiration: problems and solutions

Oocytes of nonhuman primates such as rhesus monkeys are excellent models for diverse studies on developmental biology, epigenetics, human reproduction, and assisted reproductive technologies, as well as on transgenics. Such studies require numerous oocytes that can be retrieved after controlled ovarian stimulation. Currently, most primate centers use laparoscopic aspiration or laparotomy followed by aspiration to collect rhesus oocytes, although the ultrasound-guided needle aspiration is more advantageous due to reduced infection risk, less injury, and a shorter recovery period. Yet, some initial difficulties associated with the ultrasound-guided needle aspiration limit its broader application. The objective of the present study was to address these obstacles. By presenting practical solutions to the initial difficulties, results from our study show that it is possible to collect a mean number of 38 +/- 10 rhesus oocytes per hormonally stimulated female. These results compare favorably to the average number of rhesus oocytes collected using the laparoscopic approach and suggest that when initial obstacles are overcome, the ultrasound-guided oocyte retrieval represents a good alternative to more invasive approaches.

In-vitro maturation: its role in fertility treatment

PURPOSE OF REVIEW

In-vitro maturation of oocytes was primarily developed to make in-vitro fertilization safer and simpler for women with polycystic ovaries and high risk of ovarian hyperstimulation syndrome. In-vitro maturation has potentially many advantages over conventional in-vitro fertilization. A simple protocol with decreased or no hormonal stimulation before oocyte retrieval and thus lower cost of the treatment cycle are clear benefits. More importantly, the risk of ovarian hyperstimulation syndrome is entirely avoided.

RECENT FINDINGS

The clinical outcome has substantially improved in recent years with pregnancy rates between 20 and 54%. The birth of approximately 400 children has been reported in the literature, but about three times as many are known to have been born. The postnatal follow-up studies of the children have been reassuring.

SUMMARY

Although good results have been reported by some clinics, in-vitro maturation has not yet become a mainstream fertility treatment. The most important reason for this is the lower chance of a live birth per treatment compared with conventional in-vitro fertilization. Several aspects of the clinical in-vitro maturation need to be improved to give in-vitro maturation a place among assisted reproduction techniques it deserves.