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.     

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.     

Comparing the efficacy of urinary and recombinant hCG on oocyte/follicle ratio to trigger ovulation in women undergoing intracytoplasmic sperm injection cycles: a randomized controlled trial

Purpose

To compare the number of oocytes per follicles in ovulation induction with 10,000 IU urinary hCG (uhCG) and two different doses of recombinant hCG (rhCG) in women undergoing intracytoplasmic sperm injection (ICSI) cycles.

Methods

This study was a prospective, randomized controlled trial which was performed on 180 primary infertile women undergoing ICSI cycles. All eligible patients underwent a standard GnRH-a long protocol. When at least two follicles reached a diameter of 18 mm, all patients were randomized to receive 10,000 IU urinary hCG or 250 μg recombinant hCG or 500 μg recombinant hCG for ovulation induction. Primary outcome measure included the number of oocytes retrieved per aspirated follicles. Secondary outcome measures were the number of oocytes retrieved, the number of mature oocytes, the number and quality of generated embryos, fertilization rate, implantation rate, chemical and clinical pregnancy rates and OHSS occurrence rate.

Results

The mean number of retrieved oocytes per follicles were 71.82 ± 15.09, 69.84 ± 17.44 and 77.16 ± 17.61 in 10,000 IU uhCG, 250 μg rhCG and 500 μg rhCG, respectively which was significantly higher with 500 μg rhCG than the lower dose(P = .04). Other cycles and clinical outcomes were comparable between groups.

Conclusion

Recombinant hCG shows equivalent efficacy to urinary hCG in terms of the number of oocytes per aspirated follicles in selected patients undergoing ICSI; however, 500 μg rhCG seems to be more advantageous than the lower dose in this indication. Larger randomized trials are needed to generalize this strategy.ClinicalTrials.gov identifier: NCT01507376.     

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.     

Correlation between follicular diameters and flushing versus no flushing on oocyte maturity,fertilization rate and embryo quality

Objective

To determine (a) the correlation between follicular sizes, oocyte maturity, normal fertilization rate, cleavage and embryo quality; and (b) to establish whether oocytes recovered with or without follicular flushing have different developmental competence.

Design

Prospective observational study.

Setting

Academic medical center.

Patients

Forty nine cycles (37 ICSI and 12 IVF).

Interventions

Measurement of 360 follicular diameters on the day of egg retrieval and classification into three groups Group A (mean diameter 12–14.5 mm.), group B (mean diameter 15–18 mm.) and group C (diameter >18.5 mm.).

Main outcome measure

Correlation between follicular size at the time of retrieval and oocyte maturity, fertilization and cleavage rate in 226 oocytes (163 ICSI and 63 IVF). Developmental competence of oocytes retrieved with flushing versus non flushing.

Results

Almost all (99 %) of the oocytes recovered from follicles of group C were in metaphase II as opposed to 80 % in group A and 81 % in group B (p < 0.01). Overall there was a progressive and significant increase in fertilization rates from group A follicles to group C (47 % vs. 67 %, p 0.05). Overall 53 % of oocytes retrieved from group A follicles showed either no fertilization or abnormal fertilization versus 27 % in group C (p 0.05). The oocyte recovery rate with follicular flushing improved from group A to group B and to group C follicles (65 % vs. 49 % vs.37 % respectively p < 0.01). There were no differences in rates of immature oocyte, fertilization, abnormal or not fertilization and cleavage.

Conclusions

The results of this study shows that: a) Follicles larger than 18 mm at retrieval have consistently mature oocytes with a higher rate of fertilization; b) Small size follicles are still capable of containing mature oocytes, but their rate of abnormal or no fertilization is high; c) Oocytes recovered with flushing are still able to produce embryos with full developmental competence.     

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.     

Total fertilization failure: is it the end of the story?

Purpose

To study parameters that could predict in-vitro fertilization (IVF) success in patients who experienced total fertilization failure (TFF) with intracytoplasmic sperm injection (ICSI) in their previous cycles.

Methods

Cycle characteristics of patients with TFF (Group I, n = 136 cycles), cycles resulting in embryo transfer (ET) following TFF (Group II, n = 36 cycles) and recurrent TFF (Group III, n = 25 cycles) and were studied retrospectively. Demographic features, cycle characteristics of three groups were compared.

Results

Follicle count measuring 15–17 mm was significantly higher in group II when compared to group I (p = 0.02). Total number of retrieved oocytes and mature oocytes were significantly higher in group II when compared to groups I and III (p = 0.001). Estradiol level at oocyte pick up (OPU) day was significantly higher in group II when compared to group I (p = 0.02). When the characteristics of ET cycles and preceding TFF cycles of the same patient were compared, total number of retrieved oocytes (5.11 ± 0.72 (95 % CI 3.69–6.52) vs. 11.44 ± 1.60 (95 % CI 5.29–17.59)) and mature oocytes (3.26 ± 3.66 (95 % CI 2.04–4.47) vs. 6.92 ± 5.61 (95 % CI 5.09–8.75)) were found to be significantly lower in TFF cycles (p = 0.001). Five biochemical and 5 clinical pregnancies occurred while only 2 healthy babies were born, corresponding to a live birth rate 5.5 %.

Conclusions

Increasing the number of retrieved and mature oocytes may increase the success of fertilization in patients with a history of previous failed fertilization. However, live birth rate is still low in embryo transfer cycles.     

Double-strand DNA breaks and repair response in human immature oocytes and their relevance to meiotic resumption

Purpose

Only 50–60 % of immature human oocytes attain the mature stage in vitro. Such a deficiency may be a reflection of inadequate conditions of in vitro maturation (IVM) or a manifestation of intrinsic oocyte defects. In the present study, we explored the possibility that the DNA of immature oocytes may be damaged and that such a condition, or inability to trigger a repair action, is associated to germinal vesicle (GV) arrest.

Methods

Immature oocytes (GV-stage oocytes) were obtained from women undergoing stimulated (Stim-C) or IVM (IVM-C) cycles. GV oocytes obtained from stimulated cycles were fixed for successive analysis either after recovery (T0) or following 30 h (T30) of culture if still arrested at the GV stage. Oocytes retrieved in IVM cycles were used only if they were found arrested at the GV stage after 30 h (T30) of culture. All oocytes were fixed and stained to detect chromatin and actin. They were also assessed for positivity to γH2AX and Rad51, markers revealing the presence of double-strand DNA breaks and the activation of a DNA repair response, respectively. Labelled oocytes were analysed using a Leica TCS SP2 laser scanning confocal microscope.

Results

In Stim-C oocytes, γH2AX positivity was 47.5 and 81.5 % in the T0 and T30 groups, respectively (P = 0.003), while γH2AX-positive oocytes were 58.3 % in the IVM-C T30 group (Stim-C T0 vs. IVM-C T30, P = 0.178; Stim-C T30 vs. IVM-C T30, P = 0.035). Positivity for nuclear staining to Rad51 occurred in 42.1 and 74.1 % of Stim-C in the T0 and T30 subgroups, respectively (T = 0.006), while 66.7 % of IVM-C T30 oocytes resulted positive for a DNA repair response (Stim-C T0 vs. IVM-C T30, P = 0.010; Stim-C T30 vs. IVM-C T30, P = 0.345).

Conclusions

The present data document the existence of double-strand DNA breaks (DSBs) in human immature oocytes. Also, they are consistent with the hypothesis that insults to DNA integrity may be an important factor affecting meiotic resumption.     

Day 3 ET,single blastocyst transfer (SBT) or frozen-thawed embryo transfer (FET): which is preferable for high responder patients in IVF/ICSI cycles?

Purpose

To compare the clinical outcomes after day 3 embryo transfer, day 5 single blastocyst transfer (SBT) and frozen-thawed embryo transfer (FET) in high responder patients (>15 retrieved oocytes) undergoing IVF/ICSI treatment.

Methods

A retrospective analysis of three embryo transfer strategies for the high responder patients in IVF/ICSI cycles. The 1041 high responder patients diagnosed as primary infertility with more than 15 oocytes retrieved were recruited in Day 3 ET group, 308 patients with more than 15 oocytes retrieved first transferred with one blastocyst in SBT group and 425 patients with more than 15 oocytes retrieved in fresh cycle, first transferred with one frozen-thawed blastocyst were assigned in FET group.

Results

In the high responder patients, the clinical pregnancy rate after day 5 SBT was significantly lower than that of day 3 ET (43.18 % VS 57.16 %, p < 0.05). In addition, the clinical pregnant rate and implantation rate of FET cycles were significantly higher than SBT cycles (59.06 % vs. 43.18 % and 64.70 % vs. 47.40 %, p < 0.05). The multiple pregnancy rate in FET cycles was markedly lower than that of day 3 ET (2.35 % VS 34.97 %, p < 0.05).

Conclusions

FET was the preferable strategy for the high responder patients in IVF/ICSI cycles to obtain both desirable clinical outcome and lower multiple pregnancy rates.     

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.     

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.     

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.     

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.     

Pregnancy with oocytes characterized by narrow perivitelline space and heterogeneous zona pellucida: is intracytoplasmic sperm injection necessary?

Purpose

This retrospective study analyzed fertilization protocols and pregnancy outcomes for oocytes with with narrow perivitelline space and heterogeneous zona pellucid (NPVS/HZP).

Methods

In 63 in-vitro fertilization cycles filled with NPVS/HZP oocytes (abnormal oocytes group) and 521 cycles with normal oocytes (normal oocytes group), major clinical and laboratory parameters were recorded and compared in different fertilization cycles (conventional IVF cycles, rescue ICSI cycles, and traditional ICSI cycles).

Results

NPVS/HZP oocytes meant lower MIIoocytes rates in both IVF and ICSI cycles compared with normal oocytes (p < 0.05). The 2PN rates for abnormal oocytes were significantly lower than those for normal oocytes in both conventional IVF cycles (58.8 % VS 71.3 %, P < 0.05) and rescue ICSI cycles (58.0 % VS 78.0 %, P = 0.0000). The high-quality embryo rates in normal oocytes groups were significantly higher than those in abnormal oocytes groups in different fertilization cycles (52.2 % VS 35.0 %, P < 0.01; 42.9 % VS 23.9 %, P < 0.001; 50.6 % VS 31.0 %, P = 0.0000, respectively). No clinical pregnancy was obtained from abnormal oocytes in 11 conventional IVF cycles. The clinical pregnancy rates in rescue ICSI and traditional ICSI cycles were comparatively lower in abnormal oocytes groups, but there was no significant difference as compared with normal oocytes groups (35.0 % VS 48.1 % and 26.7 % VS 50.7 %, P > 0.05, respectively).

Conclusions

Retrieval of oocytes characterized by NPVS/PZP from cycle to cycle was one of the reasons for obscure infertility. ICSI may be the right way to avoid fertilization failure and get pregnancy in women with NPVS/HZP oocytes.     

Low utilization of extra embryos in donor oocyte in vitro fertilization cycles: an ethical dilemma to donor management

Purpose

To explore outcomes of donor In Vitro Fertilization (IVF) cycles with regards to cryopreservation and utilization of extra embryos after fresh transfer.

Methods

A database search was performed to identify all consecutive fresh donor oocyte cycles from January 1, 2000 to December 31, 2010 at a private fertility laboratory. Parameters analyzed included: number of oocytes retrieved, number of patients choosing embryo cryopreservation, number of patients returning for frozen embryo transfer (FET), and pregnancy outcomes.

Results

A total of 1070 fresh oocyte donor cycles were identified. Average number of oocytes retrieved was 16.9 ± 7.9, and average number of embryos transferred was 2.3 ± 0.96. Sixty-six percent of patients cryopreserved excess embryos following fresh transfer, and only 40 % of these patients ultimately returned for FET. Patients who conceived in their fresh cycle were much less likely to return for FET than those who did not (25 % v 65 %, p < 0.001), however chance of conceiving with FET was no different between these two groups (38 % v 38 %, NS).

Conclusions

An unexpectedly low number of patients undergoing a donor oocyte IVF cycle will ultimately return to utilize extra embryos from their fresh cycle. This is concerning considering the high numbers of oocytes retrieved and the known complications from hyperstimulation, especially in light of the relatively high pregnancy rates associated with donor cycles. This raises concerns not only for donor management, but also raises ethical dilemmas when considering the large numbers of remaining embryos that will never be utilized.     

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.     

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.     

Is the presence of a non-cleaved embryo on day 3 associated with poorer quality of the remaining embryos in the cohort?

Purpose

Morphological evaluation is currently considered the single most important predictive measure for assessing embryo quality. The aim of this study was to investigate whether cycles with at least one non-cleaved embryo (i.e., a 1-cell embryo on day 3) have different outcomes compared with cycles in which all embryos had cleaved by day 3.

Methods

All autologous IVF/ICSI cycles with a fresh day 3 transfer and without using a gestational carrier performed at our center between 1/1/2010 and 12/31/2011 were analyzed retrospectively. Those cycles with at least one non-cleaved embryo on day 3 were compared with all other autologous cycles that had l00 % cleaved embryos performed during the study period.

Results

Eight hundred and forty two cycles were included. Of them, 144 cycles comprised the non-cleaved group, and 698 cycles comprised the cleaved group. Cycles in the non-cleaved group had more oocytes retrieved (15.4 ± 7.1 vs. 12.5 ± 7.1, p < 0.001), more zygotes obtained (10.0 ± 5.3 vs. 7.9 ± 5.2, p = <0.001), but the embryos exhibited lower cleavage rates and higher rates of fragmentation and asymmetry compared with controls (p < 0.001). However, spontaneous abortion rates, ectopic pregnancies rates as well as delivery rates were similar between the two groups.

Conclusions

Our results show that the presence of a non-cleaved embryo on day 3 is associated with a more exuberant response to controlled ovarian stimulation as reflected by more oocytes retrieved. Despite the significant decrease in quality of the whole cohort in the non-cleaved group, implantation, delivery rates and number of embryos frozen were not adversely affected by the presence of a non-cleaved embryo.     

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.