Polar body fragmentation in IVM oocytes is associated with impaired fertilization and embryo development

Purpose

The significance of finding a fragmented first polar body in an oocyte prepared for ICSI is controversial with most recent publications suggesting that it is not prognostic for oocyte fertilization or embryo development. Our purpose was to look at this question in the context of oocytes not stimulated for conventional IVF.

Methods

Oocytes obtained for IVM and obtained from follicles at most 12 mm in diameter were evaluated for their polar body morphology soon after they entered metaphase II when they were denuded in preparation for ICSI. Records were evaluated retrospectively for the fertilization rate and the embryo growth rate (cell number) on each day of development for embryos with normal appearing polar bodies or fragmented polar bodies, but no other cytoplasmic dysmorphisms.

Results

Oocytes with fragmented polar bodies were significantly less likely to fertilize than oocytes with normal appearing polar bodies (p < 0.0001). Embryos which developed from oocytes with fragmented polar bodies had significantly impaired growth compared to embryos that developed from oocytes with normal appearing polar bodies (p = 0.0328).

Conclusions

Fragmented polar bodies likely reflect cytoplasmic incompetence.     

Cumulus cell-oocyte complexes retrieved from antral follicles in IVM cycles: relationship between COCs morphology, gonadotropin priming and clinical outcome

Purpose

To assess retrospectively the developmental potential of different types of cumulus cell-oocyte complexes (COCs) derived from IVM cycles.

Methods

IVM cycles were performed in natural cycles or after HCG, FSH, or FSH/HCG priming. COCs recovered were morphologically characterized in different types: compact (CC) or expanded (EC) cumulus mass but including an immature oocyte, and expanded cumulus mass enclosing a mature oocyte (EC-MII). Embryo developmental competence was investigated analysing exclusively cycles in which all transferred embryos derived from the same COC category.

Results

Fertilization rates did not differ significantly. Significant differences in pregnancy rates (14.5 %, 10.0 % and 27.6 % in the CC, EC, and EC-MII categories, respectively) were observed. Likewise, significant differences in implantation rates (8.9 %, 6.3 % and 19.1 % in the CC, EC, and EC-MII categories, respectively) were found. Overall, priming with FSH/HCG had a beneficial effect on pregnancy and implantation rates, while no priming or HCG alone generated oocytes with poor competence.

Conclusions

In IVM cycles, morphological evaluation at the time of collection can predict the developmental ability of different COCs. FSH/HGC priming has a positive effect on oocyte competence.     

Comparison of fertilization and embryonic development in sibling in vivo matured oocytes retrieved from different sizes follicles from in vitro maturation cycles

Purpose

To examine the fertilization and developmental potential of sibling mature oocytes collected from different follicle sizes on day of retrieval in in vitro maturation (IVM) cycles.

Methods

Two hundred thirty eight hCG-primed IVM cycles were performed in 213 patients with polycystic ovaries. If sibling mature oocytes were retrieved on day of collection, they were divided into two groups, Group 1 (n = 78): M-II oocytes obtained from follicles size 10–14 mm; Group 2 (n = 192): M-II oocytes obtained from follicles size <10 mm.

Results

Of the 238 cycles, 63 cycles had more than one M-II oocytes retrieved (total M-II oocytes = 270) both from Groups 1 and 2. There were no significant differences between the two groups for oocyte diameter (117.2 mm vs. 116.9 mm), fertilization (79.5% vs. 72.4%) and good quality embryo on day 3 (66.1% vs. 56.8%).

Conclusions

The M-II oocytes retrieved from the cohort of follicles (<10 mm diameter) can produce the same quality of embryos as that from large follicles, likely contributing to improve the clinical outcome.     

Fertilization, embryo development, and clinical outcome of immature oocytes obtained from natural cycle in vitro fertilization

Purpose

To analyze the fertilization, embryo development, and clinical outcome of immature oocytes obtained from natural cycle IVF in women with regular cycles.

Methods

Natural cycle IVF was performed in 28 patients who had normal ovaries, > 6 antral follicle counts and were less than 40 years old (n = 28 cycles). An hCG trigger of 10,000 IU was administered 36 h before oocyte collection when the diameter of the dominant follicle (DF) was over 12 mm. Oocytes were retrieved from DF as well as from the cohort of smaller follicles. Embryological aspects of the mature and immature oocytes retrieved from these cycles as well as the implantation and clinical pregnancy rates depending on the origin of the embryos transferred were evaluated.

Result(s)

Overall clinical pregnancy and implantation rates were 20.8 % and 6.7 %, respectively. There were no differences in in vitro maturation (IVM), fertilization and embryo development between immature oocytes retrieved with and without in vivo matured oocytes. However, the clinical and implantation rates in cycles with embryos produced from in vivo matured oocytes transferred were better than the cycles where only IVM embryos were transferred (30.8 %, 9.1 % vs. 9.1 %, 3.2 %).

Conclusion(s)

Although our results show that immature oocytes from natural cycle IVF can fertilize normally and can be used to increase the number of embryos available for transfer, the embryos derived from the immature oocytes in natural cycles IVF have a poorer reproductive potential.     

In-vitro maturation of human oocytes: before or after vitrification?

Purpose

This study aims to determine if in-vitro maturation (IVM) of human immature oocytes should be performed before or after vitrification.

Methods

A total of 184 immature oocytes were randomly divided into two different groups: 100 were vitrified at metaphase II (MII) stage 24 h-48 h after IVM (group 1) and 84 were immediately vitrified at germinal vesicle (GV) or metaphase I (MI) stages and in vitro matured after warming (group 2).

Results

Survival rate after warming was similar in both groups (86.9% versus 84.5%). However, oocyte maturation rate per collected oocyte was significantly higher for oocytes matured before vitrification (group 1, 46%) than for oocytes vitrified before IVM (group 2, 23.8%) (p < 0.01). Consequently, the number of MII oocytes inseminated per oocyte collected was significantly higher for group 1 (40%) than for group 2 (23.8%) (p < 0.05).

Conclusion

IVM procedure is more efficient when it is performed before oocyte vitrification.     

Clinical outcomes from mature oocytes derived from preovulatory and antral follicles: reflections on follicle physiology and oocyte competence

Purpose

The aim of this retrospective study was to compare the competence of oocytes obtained from preovulatory and antral follicles.

Methods

Mature oocytes from preovulatory follicles were retrieved from women selected for standard IVF treatment (Group A). Mature oocytes from antral follicles were recovered from women undergoing hCG-primed in vitro maturation (IVM) treatment (Group B). Patients groups were matched for age, BMI, FSH, AMH and antral follicle count (AFC) values. In vivo matured oocytes from both groups were microinjected and resulting embryos were culture and selected on day 3 for embryo transfer.

Results

Oocyte pick-ups (OPU) were 315 and 204 in Groups A and B, respectively. Fertilization rates were comparable (72.8 and 75.9 %, respectively; P = 0.137). In Group A, in which the average number of embryos transferred was higher, clinical pregnancy rates per OPU (37.5 %) and embryo transfer (38.4 %) were superior in comparison to Group B (27.0 %, P = 0.013; 29.4 %, P = 0.041; respectively). On the other hand, implantation rates (Group A, 23.7 %; Group B, 20.8 %) and proportions of babies born per transferred embryo (Group A, 19.5 %; Group B, 16.9 %) were similar (P = 0.528 and 0.332, respectively).

Conclusions

Overall, this suggests that oocyte competence is already achieved at the antral stage of follicle development.     

Spontaneous in vitro maturation of oocytes prior to ovarian tissue cryopreservation in natural cycles of oncologic patients

Purpose

To evaluate the recovery rate and spontaneous in vitro maturation (IVM) of immature oocytes enclosed within or released from follicles during the processing of ovarian tissue prior to its cryopreservation.

Methods

Thirty-three oncologic patients who had not previously undergone chemo or radiotherapy underwent ovarian tissue cryopreservation (OTC) during natural menstrual cycles. Immature oocytes, enclosed within follicles or released during ovarian cortex processing, were collected and matured spontaneously in vitro for 48 h. Nuclear maturation was assessed every 24 h and the ability of the IVM oocytes to display a normal activation response following parthenogenetic activation was evaluated. The following outcome measures were also evaluated: disease, age, FSH, LH, E2, P4 and AMH serum levels, menstrual cycle day, recovery and spontaneous IVM and parthenogenetic activation rates.

Results

Oocytes recovered per patient were 3.3 ± 0.7 (1.8–4.7 oocytes, 95CI), regardless of the menstrual phase. The mean number of IVM oocytes per patient was 1.3 ± 0.2 oocytes (95CI: 0.8–1.8), regardless of menstrual phase (p = 0.86) and oocyte origin (p = 0.61). Forty-one percent of oocytes extruded the second polar body and formed one pronucleus after parthenogenetic activation.

Conclusion

Twenty-one of the 33 women (63.6 %) requesting OTC produced at least one mature oocyte.     

Serum anti-Mullerian hormone levels correlate with ovarian response in idiopathic hypogonadotropic hypogonadism

Purpose

The role of serum AMH levels in prediction of ovarian response in idiopathic hypogonadotropic hypogonadism (IHH) was evaluated.

Material method(s)

Twelve patients with IHH underwent controlled ovarian hyperstimulation (COH) for IVF were enrolled in this prospective study. Serum AMH levels were studied on the 2nd or 3rd day of an induced menstrual cycle by a preceding low-dose oral contraceptive pill treatment. A fixed dose (150–300 IU/day) of hMG was given in all COH cycles. Correlations between serum AMH levels, COH outcomes and embryological data were investigated.

Results

Mean serum AMH levels was 3.47 ± 2.15 ng/mL and mean serum peak estradiol was 2196 ± 1705 pg/mL. Mean number of follicles >14 mm, >17 mm on hCG day and MII oocytes were 4.14 ± 3.2, 4 ± 2.5 and 7.28 ± 3.5, respectively. Mean number of grade A embryos and transferred embryos were 3.28 ± 2.4 and 2.5 ± 0.7, respectively. The clinical pregnancy rate per patient was 41.6 % (5/12). Positive correlations were observed between serum AMH levels and MII oocytes (r = 0.84), grade A embryos (r = 0.85), serum peak estradiol levels (r = 0.87), and number of follicles >14 mm (r = 0.83) and >17 mm (r = 0.81) on hCG day, respectively.

Conclusion

AMH appears as a promising marker of ovarian response in patients with IHH undergoing IVF.     

Supplementation with low concentrations of melatonin improves nuclear maturation of human oocytes in vitro

Purpose

Studies in bovine and porcine have indicated that melatonin (MT) could induce meiotic maturation of immature oocytes in vitro. The object of the current study was to investigate if MT could ameliorate human oocytes maturation during rescue in vitro maturation (IVM).

Methods

Two hundred seventy eight germinal vesicle (GV) oocytes and 451 (MI) metaphase I oocytes were vitrified, thawed and then matured in vitro. All the oocytes were randomly allocated into six groups in which the oocytes were cultured in medium supplemented with different concentrations of MT (0, 10⁻², 1, 10², 10⁴, 10⁶ nM) and nuclear maturation was evaluated at 6 h, 12 h, 18 h, 24 h and 48 h of culture.

Results

The optimal MT concentration for both GV and MI oocytes was 1 nM. At 24 h of culture, nuclear maturation rate of MI oocytes cultured in 1 nM MT medium was significantly higher than other groups (P < 0.05); Nuclear maturation rate of GV oocytes cultured in 1 nM MT medium was also significantly higher than the control group (P < 0.05). On the other hand, decreased nuclear maturation rate was observed in the high MT concentration group (10⁶ nM).

Conclusions

The current study demonstrated that low concentration of exogenous MT could ameliorate nuclear maturation of human oocyte during rescue IVM, while high concentration of MT presented negative effects.     

Laparoscopic excision of ovarian endometrioma does not exert a qualitative effect on ovarian function: insights from in vitro fertilization and single embryo transfer cycles

Purpose

To evaluate whether laparoscopic excision of endometrioma exerts a qualitative effect on ovarian function.

Methods

A retrospective analysis of oocytes retrieved in 25 cycles of 21 patients undergoing IVF treatment with controlled ovarian stimulation. The number of oocytes recovered from ovaries with a history of excision of endometrioma (E-Ov) were compared to those from contra-lateral healthy ovaries (H-Ov) as for the analysis of a quantitative effect of surgery. As for the analysis of a qualitative effect, 55 oocytes from E-Ov were compared to 128 oocytes from H-Ov in terms of normal fertilization rate and the rate of top-quality embryos per normally fertilized eggs. Furthermore, 10 embryos derived from oocytes recovered from E-Ov were compared to 24 embryos derived from oocytes from H-Ov in terms of clinical and on-going pregnancy rates per embryos in 34 single embryo transfer cycles.

Results

Mean number of oocytes recovered from E-Ov was significantly smaller than that from H-Ov (2.2 ± 2.0 vs. 5.1 ± 3.3, P = 0.009). There was no difference between oocytes from E-Ov and H-Ov as for normal fertilization rate (63.6 % vs. 69.5 %, P = 0.43) and the rate of top-quality embryos (40.0 % vs. 49.0 %, P = 0.34). Clinical and on-going pregnancy rates per embryos were also similar in embryos derived from oocytes recovered from E-Ov and H-Ov (40.0 % vs. 25.0 %, P = 0.39 and 20.0 % vs. 20.8 %, P = 0.96).

Conclusions

The quality of oocytes recovered from the ovary with a history of laparoscopic excision of endometrioma is not inferior to the quality of oocytes from contra-lateral healthy ovary.     

Effect of L-carnitine supplementation on maturation and early embryo development of immature mouse oocytes selected by brilliant cresyle blue staining

Purpose

The present study was designed to investigate the effect of L-carnitine treatment during IVM on nuclear and cytoplasmic maturation of immature oocytes selected by Brilliant Cresyle Blue (BCB) staining, and their subsequent developmental competence.

Materials & methods

Compact cumulus-oocyte complexes (COCs) were collected from NMRI mice ovaries and stained with BCB staining. BCB+ (colored cytoplasm) oocytes were then cultured in tissue culture medium (TCM) 199 with 0.0, 0.3 and 0.6 mg/ml L-carnitine.

Results

The both L-carnitine concentrations significantly increased the intracellular glutathione (P < 0.001), nuclear maturation (P < 0.01) and expression levels of cyclin-dependent kinase1 (CDK1) (P < 0.05). Moreover, treated oocytes with 0.6 mg/ml L-carnitine showed increased (P < 0.05) expression of mitogen-activated protein kinase1 (MAPK1) mRNA. Also, adding L-carnitine (0.6 mg/ml) to IVM medium significantly increased the cleavage rate (P < 0.05). The blastocyst development rate (BDR) in the both L-carnitine treated groups was significantly higher (P < 0.001) than the control group. L-carnitine had no significant effect on total blastocyst cell numbers.

Conclusions

These data indicated that L-carnitine supplementation during IVM of immature BCB+ oocytes improved preimplantation developmental competence of oocytes after IVF, probably by accelerating cytoplasmic and nuclear maturation of oocytes. It may provide a novel approach to improving ART outcomes in infertile couples.     

The influence of amifostine administration prior to cyclophosphamide on in vitro maturation of mouse oocytes

Purpose

The protective effect of amifostine against cyclophosphamide (CP) was evaluated on mouse oocytes.

Materials and methods

Female mice were divided into four groups as follows: group1: cyclophosphamide (CP) (75 mg/kg, i.p) injection, group2: amifostine (250 mg/kg, i.p) injection, group3: amifostine (250 mg/kg, i.p) administered prior to CP (75 mg/kg, i.p) injection, Control group with injection of saline. About 21 days after injection, in vitro maturation (IVM) of oocytes was recorded. Furthermore the percentage of aneuploid oocytes was determined.

Results

In the CP group IVM rate was significantly decreased and aneploidy rate was significantly increased when compared to other groups (p < 0.05). With the administration of Amifostine prior to CP injection IVM rate was increased and aneploidy rate was decreased.

Discussion

Depletion in IVM rate with administration of CP is due its adverse effects on oocyte quality. Amifostine administration prior to CP injection appears to modulate deleterious effects of CP on oocytes.     

“Mild” vs. “long” protocol for controlled ovarian hyperstimulation in patients with expected poor ovarian responsiveness undergoing in vitro fertilization (IVF): a large prospective randomized trial

Background

This large prospective, randomized study was designed to compare the “mild” protocol with clomiphene citrate, low-dose gonadotropins and a GnRH-antagonist (CC/Gn/GnRH-ant protocol) with the “long” protocol with a GnRH-agonist and high-dose Gn for the controlled ovarian hyperstimulation (COH) of patients with expected poor ovarian responsiveness undergoing IVF.

Materials and Methods

A total of 695 women with clinical, endocrine and ultrasound characteristics suggesting a low ovarian reserve and a poor responsiveness to COH were recruited and randomly assigned to receive the CC/Gn/GnRH-ant “mild” protocol (mild group, n = 355) or the “long” protocol with high-dose Gn (long group, n = 340).

Results

The “mild” stimulation led to significantly shorter follicular phase, lower consumption of exogenous Gn and lower peak estradiol level than the “long” regimen. With the “long” protocol, significantly less cycles were cancelled due to the lack of ovarian response; further, it obtained significantly more oocytes, more mature oocytes, more embryos, and a thicker endometrium. As for the final IVF outcome, however, the two stimulation regimens obtained comparable implantation rate, clinical pregnancy rate, and ongoing pregnancy rate at 12 weeks.

Conclusions

In conclusion, the “mild” CC/Gn/GnRH-ant stimulation protocol is a valid alternative to the long protocol with high Gn dose as it obtains a comparable success rate and requires significantly less medications, with an obvious economical advantage.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-014-0227-y) contains supplementary material, which is available to authorized users.     

What is the optimal threshold of serum Anti-Müllerian hormone (AMH) necessary for IVM treatments?

Purpose

To assesse circulating levels of Anti-Müllerian hormone (AMH) as a predictor of oocyte number and their potential to mature in vitro in both normo-ovulatory (NO) women and in women with Polycystic Ovary Syndrome (PCOS) undergoing in vitro maturation (IVM) treatments.

Methods

We prospectively studied NO women and women diagnosed with PCOS, (age range 21–39 years) underwent IVM treatments at our center. Serum AMH levels were quantified before each cycle and correlated to oocytes number, maturation and fertilization during in vitro maturation.

Results

104 NO and 30 PCOS IVM cycles were followed with retrieval of a total of 672 and 491 oocytes, respectively. In NO women, the serum AMH level positively correlated with the number of oocytes retrieved, (R = 0.6; P <0.0001) the number of M2 oocytes at 24 and 48 h (R = 0.4; P <0.01; R = 0.26 p < 0.007, respectively) and with the total number of M2 oocytes (R = 0.47; P < 0.0001). In the PCOS group, the serum AMH level positively correlated only with the number of oocytes retrieved (R = 0.43; P <0.03). Receiver operating characteristic (ROC) analyses showed that a cutoff AMH level of 1.56 (ng/ml) could identify patients with 5 or more oocytes at OPU with a sensitivity of 83 % and a specificity of 75 %. An AMH level of 1.63 (ng/ml) was the threshold for 5 or more matured oocytes (sensitivity = 81 %, specificity = 53 %).

Conclusions

Serum AMH may be used as a marker to identify candidates for IVM treatment in both NO and PCOS women.     

Effects of differing oocyte-secreted factors during mouse in vitro maturation on subsequent embryo and fetal development

Purpose

We hypothesised that varying native oocyte-secreted factor (OSF) exposure or using different recombinant OSF peptides would have differential effects on post-in vitro maturation (IVM) embryo and fetal development.

Methods

Mouse cumulus oocyte complexes (COCs) were treated with the purified mature domain of GDF9 and/or BMP15 or were co-cultured with denuded oocytes (DOs) from 0 h or 3 h of IVM. DOs were matured for 3 h as either intact COCs+/-FSH before denuding, or as DOs + FSH. COCs were fertilised and blastocyst development was assessed on days 5 and 6, and either differentially stained for ICM numbers or vitrified/warmed embryos were transferred to recipients to assess implantation and fetal rates.

Results

No improvement in embryo development was observed with the addition of GDF9 and/or BMP15 to IVM. In contrast, embryos derived from COCs co-cultured with DOs had significantly improved blastocyst rates and ICM numbers compared to controls (P < 0.05). The highest response was obtained when DOs were first added to COCs at 3 h of IVM, after being pre-treated (0–3 h) as COCs + FSH. Compared to control, co-culture with DOs from 3 h did not affect implantation rates but more than doubled fetal yield (21 % vs 48 %; P < 0.05). GDF9 Western blot analysis was unable to detect any differences in quantity or form of GDF9 (17 and 65 kDa) in extracts of DO at 0 h or 3 h.

Conclusions

This study provides new knowledge on means to improve oocyte quality in vitro which has the potential to significantly aid human infertility treatment and animal embryo production technologies.     

Polarized light microscopy-detectable structures of human oocytes and embryos are related to the likelihood of conception in IVF

Purpose

To clarify if birefringent structures of human oocytes and embryos, measurable by polarized light microscopy, have any value in predicting the chance of pregnancy in human in vitro fertilization and may halp to identify the most competent oocytes and embryos.

Methods

The inner layer of the zona pellucida (IL-ZP) and the meiotic spindle (MS) were analyzed by polarized light microscopy in 258 oocytes and in the 209 embryos deriving from them. Data obtained from 102 ICSI cycles with conception were compared with those obtained in 156 cycles without conception. The retardance and area of the IL-ZP, as well as the retardance, length of the major axis, and area of the MS were measured. Furthermore, polarized light microscopy parameters were related to the embryo morphological score by multiple regression analysis.

Result(s)

The mean area of the IL-ZP of both oocytes and embryos was significantly lower in conception than in non-conception cycles (p = 0.0001 for oocytes and p = 0.002 for embryos). The area of the IL-ZP in embryos was significantly, inversely related to the embryo morphological score (p = 0.011). The area, the major axis length and the retarcance of the MS, as well as the retardance of the IL-ZP in oocytes and embryos were comparable in conception and non-conception cycles.

Conclusion

The area of the IL-ZP of the human oocytes may represent a marker of oocyte competence, as oocytes with a low IL-ZP area are more frequently obtained in conception cycles. When measured in embryos, a low IL-ZP area identifies embryos with a high chance of implantation.     

Progesterone levels on the hCG day and outcomes in vitro fertilization in women with polycystic ovary syndrome

Background

The purpose of this study was to determine the incidence of premature luteinization in patients with polycystic ovary syndrome and compared the main determinants of success in in-vitro fertilization in PCOS patients with and without premature luteinization.

Methods

Retrospective analysis of 180 PCOS women of Chinese Han origin with infertility who underwent controlled ovarian hyperstimulation (COH) with an exogenous gonadotropin/GnRH antagonist protocol. Hormone levels on the hCG day and IVF outcomes were assessed.

Results

The incidence of premature luteinization was 23.3 %. Compared with PCOS patients without premature luteinization, PCOS patients with premature luteinization(PL) had a higher number of oocytes retrieved (18.20 ± 6.6 vs 15.08 ± 7.3, p = 0.037) and a higher fertilization rate (72.9 ± 1.9 vs63.1 ± 2.3, p = 0.033), but clinical pregnancy rates were no statistical significance (53.3 vs 56.0, p = 0.836). Though the implantation rate was higher in no premature luteinization patients, but the difference was not statistically significant (37.7 vs 30.3, p = 0.115).

Conclusion

The PCOS patients with premature luteinization had a higher fertilization rate and high number of oocytes retrieved, and the similar implantation rate and clinical PRs as PCOS patients without premature luteinization.     

The impact of vitrification on murine germinal vesicle oocyte In vitro maturation and aurora kinase A protein expression

Purpose

Investigate the effect of vitrification on in vitro maturation (IVM) and expression of Aurora kinases A, B, and C in germinal vesicle (GV)-stage oocytes.

Methods

GV-stage oocytes from B6D2F1 female mice 7–11 weeks of age were vitrified after collection, thawed, and matured in vitro for 0, 4, 8, and 12 h (hrs). The rate of germinal vesicle breakdown (GVBD), spindle apparatus assembly, and Aurora kinase mRNA and protein expression during IVM was measured.

Results

Oocyte vitrification was associated with significant delays in both GVBD and normal spindle apparatus assembly at 4 and 8 h of IVM (p < 0.05). There was no difference in mRNA levels between control and vitrified oocytes for any of the Aurora kinases. Aurora A protein levels were reduced in vitrified compared to control oocytes at 0 h (p = 0.008), and there was no difference at 4 and 8 h (p = 0.08 and 0.69, respectively) of IVM.

Conclusions

Vitrified oocytes have delayed GVBD and normal spindle assembly during in vitro maturation. Reduced levels of Aurora A protein immediately post-thaw may be associated with the impaired oocyte maturation manifested by the delayed progression through meiosis I and II, and the atypical timing of the formation of meiotic spindles in vitrified GV-stage oocytes.     

Reduced uterine receptivity for mouse embryos developed from in-vitro matured oocytes

Purpose

The outcomes of in-vitro maturation (IVM) are inferior compared to those of IVF. The purpose of the study was to compare the implantation rates of IVM- and in-vivo maturation (IVO)- derived embryos, and to evaluate their effects on uterine receptivity.

Methods

The IVM- and IVO- oocytes were obtained from female mice, fertilized and transferred to separate oviducts of the same pseudo-pregnant mice. After 5 days, the implanted blastocysts were dissected out of the uterine horns, and the uterine horns were analyzed for the expression of mRNAs encoding leukemia inhibitory factor, heparin-binding epidermal growth factor, insulin-like growth factor binding protein-4, progesterone receptor, and Hoxa-10.

Results

The maturation rate of the IVM- oocytes was 81.2 %. The fertilization rate of the IVM oocytes was lower than that of the IVO oocytes (50.5 % vs. 78.0 %, p = 0.038), as was their implantation rate (14.5 % vs. 74.7 %, p < 0.001). All 5 mRNAs examined were expressed at significantly lower levels in the uterine horns that received the IVM-derived embryos than in those that received the IVO-derived embryos.

Conclusions

The IVM-derived embryos are less competent in inducing expression of implantation-related mRNAs in the uterine horn.     

Follicular fluid protein content (FSH, LH, PG4, E2 and AMH) and polar body aneuploidy

Purpose

Our objective was to identify a marker for oocyte aneuploidy in follicular fluid (FF) in women with an increased risk of oocyte aneuploidy after controlled ovarian hyperstimulation.

Materials and methods

Three groups of oocytes were constituted for polar body screening by FISH (chromosomes 13, 16, 18, 21 and 22): Group 1, advanced maternal age (n = 156); Group 2, implantation failure (i.e. no pregnancy after the transfer of more than 10 embryos; n = 101) and Group 3, implantation failure and advanced maternal age (n = 56). FSH and other proteins were assayed in the corresponding FF samples.

Results

Of the 313 oocytes assessed, 35.78 % were abnormal. We found a significant difference between the follicular FSH levels in normal oocytes and abnormal oocytes (4.85 ± 1.75 IU/L vs. 5.41 ± 2.47 IU/L, respectively; p = 0.021). We found that the greater the number of chromosomal abnormalities per oocyte (between 0 and 3), the higher the follicular FSH level.

Conclusion

High FF FSH levels were associated with oocyte aneuploidy in women having undergone controlled ovarian hyperstimulation.