Follicular fluid levels of insulin-like growth factor I, insulin-like growth factor binding protein I, and ovarian steroids collected during ovum pick-up

Association of in vitro fertilization outcome with circulating insulin-like growth factor components prior to cycle initiation

OBJECTIVE

Components of the insulin-like growth factor (IGF) system enhance in vitro embryo quality and implantation rates in both animal models and human in vitro fertilization (IVF). We evaluated whether differences in serum levels of these components in women prior to initiation of an IVF cycle would be predictive of subsequent outcome.

STUDY DESIGN

In this retrospective study sera from women obtained at day 2 of their IVF cycle (at baseline before stimulation) were assayed for IGF-I, IGF-II, and IGF binding protein (BP)-1 by enzyme-linked immunosorbent assay. Samples from 54 women with a live birth, 38 with a transient biochemical pregnancy, 45 with a spontaneous abortion, 54 who did not become pregnant, and 35 who had an ectopic pregnancy were available for analysis. Associations between the assays and outcome were evaluated by the Kruskal-Wallis test and receiver operating characteristic analysis.

RESULTS

There were no differences in the number of oocytes retrieved, oocyte quality, fertilization rates, or embryo grade between groups. Median concentrations of IGF-I were elevated in women with a live birth (29.1 ng/mL) as compared to women with a biochemical pregnancy (25.6 ng/mL), with spontaneous abortion (21.2 ng/mL), who were not pregnant (18.7 pg/mL), or who had an ectopic pregnancy (4.2 pg/mL) (P < .001). Conversely, median levels of IGF-II were reduced in women with a live birth (294.5 ng/mL) as opposed to 357.5, 393.6, 407.2, and 426.9 ng/mL in women with a biochemical pregnancy, with ectopic pregnancy, with spontaneous abortion, or who were not pregnant, respectively (P < .001). Median IGFBP-1 concentrations were markedly elevated in women with a live birth (23.6 ng/mL) compared to 18.3, 14.1, 13.8, and 9.5 ng/mL in women with a biochemical pregnancy, with spontaneous abortion, who were not pregnant, or with an ectopic pregnancy (P < .001). The combination of IGF-I and IGFBP-1 best predicted the occurrence of a live birth with an area under the curve of 0.892.

CONCLUSION

Maternal serum levels of IGF-I, IGF-II, and IGFBP-1 prior to initiation of an IVF cycle are correlated with the likelihood of a live birth. Alterations in maternal IGF system components may influence oocyte quality or the success of early postfertilization events and embryo implantation.

Follicular dominance on the fifth day of controlled ovarian stimulation reduces implantation in long down-regulated ICSI cycles

OBJECTIVE

To determine if follicular dominance on the fifth day of controlled ovarian stimulation (COS) predicts implantation rates in down-regulated intracytoplasmic sperm injection (ICSI) cycles.

STUDY DESIGN

One hundred and sixty-two consecutive women undergoing ICSI treatment with long down-regulation and recombinant follicle-stimulating hormone injections were included in a prospective cohort analysis. The clinical pregnancy and implantation rates per transfer were compared between two groups, one with and the other without follicular dominance detected by ultrasound on the fifth day of COS.

RESULTS

There was no significant difference between the groups regarding the number of good quality embryos transferred, but clinical pregnancy and implantation rate per transfer were higher in group with follicular synchrony.

CONCLUSIONS

Follicular dominance on COS day 5 results in reduced implantation rates after ICSI.

Insulin-like growth factor-II (IGF-II), IGF-binding protein-3 (IGFBP-3), and IGFBP-4 in follicular fluid are associated with oocyte maturation and embryo development

OBJECTIVE

The objective of this study was to investigate the association between follicular fluid (FF) levels of insulin-like growth factors (IGFs), IGF binding proteins (IGFBPs), and pregnancy-associated plasma protein-A (PAPP-A), which is a protease for IGFBP-4, and the quality of subsequent embryo development from in vitro fertilized oocytes aspirated from the same follicle.

DESIGN

Prospective study.

SETTING

University infertility clinic and academic research laboratory.

PATIENT(S)

One hundred sixty-two infertile women undergoing controlled ovarian hyperstimulation for IVF and embryo transfer were recruited in a university hospital.

INTERVENTION(S)

During oocyte retrieval, samples of 225 FFs and matched mature oocytes were collected and studied.

MAIN OUTCOME MEASURE(S)

Concentrations of FF IGF-I, IGF-II, IGFBP-1, IGFBP-3, IGFBP-4, and PAPP-A were determined using ELISA. Progesterone secretion by cultured granulosa cells (GC) was measured by RIA.

RESULT(S)

Levels of IGF-II, IGFBP-3, and IGFBP-4 in FF on the day of oocyte retrieval were significantly correlated with embryo scores on day 3 (72 hours after oocyte retrieval). Levels of IGF-II, IGFBP-3, and IGFBP-4 in FF from follicles in which oocytes developed into day 2 embryos (48 hours after oocyte retrieval; 20 >or= embryo score >or= 6) after fertilization were significantly higher than those from follicles in which oocytes were unable to be fertilized and were arrested in embryo development on day 2, whereas the levels of PAPP-A were significantly lower in the former than the latter group. Using multiple regression analysis, we found that high levels of IGFBP-3 and IGFBP-4 combined with low levels of PAPP-A in FF were significantly correlated with successful fertilization and early development into day 2 embryos. In contrast, high FF IGFBP-1 and IGFBP-4 in combination with low FF IGF-I were significantly correlated with a later (day 2-day 3) embryo development. A significant stimulation of P secretion in cultured GCs by the combination of recombinant IGF-II, IGFBP-3, and IGFBP-4 further strengthened these proteins' functional roles in promoting late follicular development.

CONCLUSION(S)

High IGF-II, IGFBP-3, IGFBP-4, and low PAPP-A levels in FF at the time of oocyte retrieval suggest better oocyte maturation and early embryo development (within 48 hours after oocyte retrieval), whereas high IGFBP-1, IGFBP-4, and low FF IGF-I levels may favor later embryo development (between 48 and 72 hours after oocyte retrieval).

Predictive factors for embryo implantation potential

In spite of recent improvements in IVF, pregnancy rates have not increased significantly and one of the major problems remains the high multiple pregnancy rate. Better criteria are therefore necessary to establish the viability of a transferable embryo. Early prognosis of the developmental fate of the oocyte would help in selecting the best embryos to transfer, but non-invasive selection at the oocyte stage (extracytoplasmic and intracytoplasmic morphology) has proved to be of little prognostic value. Recently, it has been shown that follicular vascularization appears to be predictive of oocyte developmental fate, making it a good first-step approach for selection. Observation of pronuclei patterns at the zygote stage appears to offer an additional prognostic tool, correlating well with IVF outcome. Morphological evaluation of the embryo at days 2-3 remains the most used and valid method of selection, even though it is not sufficient to select embryos with the higher implantation potential. Blastocyst culture is another possible strategy for selecting the best embryos with reduced risk of aneuploidies, though not all major chromosomal aberrations are excluded by prolonged in-vitro culture. In summary, selecting the best embryo for transfer is a decision that should be based on choices made during the different stages of assisted reproductive technologies.

Expression of steroid receptors, their cofactors, and aromatase in human luteinized granulosa cells after controlled ovarian hyperstimulation

OBJECTIVE

To examine expression of androgen receptor (AR), AR cofactors, estrogen (E) receptor alpha, E receptor beta, progesterone receptor, steroid receptor coactivator-1, and aromatase in human luteinized granulosa cells collected during oocyte retrieval.

DESIGN

Prospective real-time reverse transcriptase-polymerase chain reaction study.

SETTING

Academic medical center.

PATIENT(S)

A total of 198 samples were brought into the study.

INTERVENTION(S)

Patients underwent the long protocol for assisted reproductive technology. Luteinized granulosa cells were collected transvaginally with ultrasound guidance. Quantitative reverse transcriptase-polymerase chain reaction was performed to quantify the mRNA expression of the investigated genes.

MAIN OUTCOME MEASURE(S)

The expression levels were determined as ratios between the studied genes and the reference gene beta-actin.

RESULT(S)

There is little AR expression in human luteinized granulosa cells immediately preceding ovulation under controlled ovarian hyperstimulation. All aspirated follicles, despite their antral size, displayed a similar mRNA expression of the investigated genes in the luteinized granulosa cells.

CONCLUSION(S)

This study supports the possibility of a transition of androgen action from being an enhancer of follicular differentiation (through the AR) to being a substrate of E synthesis (through aromatase) at the time of oocyte retrieval. The present study also demonstrates no effect of follicular size upon the status of steroid receptor mRNA expression in the luteinized granulosa cells when follicles were at least >1.5 mL.

Perifollicular vascularity monitoring and scoring: a clinical tool for selecting the best oocyte

The aim of our study was to assess relationship between perifollicular vascularity and outcome of in vitro fertilization (IVF) cycles. In our study, women who received embryos originating from oocytes developed in well vascularized follicles had a statistically higher pregnancy rate than women who received embryos chosen without considering follicles of origin.

Significance of mRNA levels of connexin37, connexin43, and connexin45 in luteinized granulosa cells of controlled hyperstimulated follicles

OBJECTIVE

To evaluate the mRNA levels of connexins in different sizes of luteinized follicles.

DESIGN

Semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the connexin mRNA levels in the granulosa cells of 91 luteinized follicles.

SETTING

Academic tertiary care medical center and research unit of university.

PATIENT(S)

Ninety-one female patients on controlled ovarian hyperstimulation (COH).

INTERVENTION(S)

Sonoguided aspiration to collect the oocytes and the granulosa cells simultaneously.

MAIN OUTCOME MEASURE(S)

The RT-PCR data are normalized by comparing the intensity of the connexins to the intensity of internal controls (beta-actin). The follicles are grouped according to the size and the mRNA levels of the connexins. The correlations among the size of the follicles, the outcome of oocytes, and the mRNA levels of the connexins are compared by Fisher's exact test and Mann-Whitney test.

RESULT(S)

The mRNA levels of the connexins are low in the follicles equal or larger than 5.5 mL. High cx43 levels are linked to good prognosis of oocytes.

CONCLUSION(S)

The luteinized granulosa cells from the large follicles are relatively quiescent in the connexin mRNA expression. In addition to the volume, the mRNA levels of cx43 may serve as a marker to predict the outcome of oocytes.

Comparison between cytokine concentration in follicular fluid of poor and high responder patients and their influence of ICSI-outcome

OBJECTIVE

The aim of this study was to compare the cytokine concentration in follicular fluid (FF) of low and high responder intracytoplasmic sperm injection (ICSI) patients and to find out the impact of these cytokines in FF on ICSI outcome.

DESIGN

The levels of insulin-like growth factor (IGF)-I, IL-6, IL-8, epidermal growth factor (EGF), platelet-derived growth factor (PDGF), granulocyte-macrophage-colony stimulating factor (GM-CSF) were measured from low and high responder ICSI patients, the results were compared between the two groups and their influence on ICSI outcome was analysed.

MATERIAL AND METHODS

A total of 49 low (G.I) and 34 high (G.II) responder patients were enrolled in this study. FF was collected at the time of oocyte retrieval and measured either by enzyme-linked immunosorbent assay (IL-6, IL8, EGF, PDGF, GM-CSF) or radio immuno assay (IGF-I).

RESULTS

The concentration of IL-6 (pg/mL), IL-8 (pg/mL), IGF-I (ng/mL), PDGF (pg/mL), EGF (pg/mL), GM-CSF (pg/mL) in G.I was 6.0 +/- 4.3, 288.1 +/- 139.2, 0.416 +/- 0.089, 249.8 +/- 150.1, 9.12 +/- 5.5 and 1.45 +/- 2.10 and the corresponding value in G.II was 7.4 +/- 4.8, 208.6 +/- 64.0, 0.431 +/- 0.094, 387.6 +/- 36.0, 8.9 +/- 5.4 and 1.8 +/- 3.3, respectively. Only the PDGF concentration showed a significant (P = 0.007) difference between the two groups. Besides, negative correlations were found between PDGF and fertilization rate (r = -0.287; P = 0.046) of G.I. The mean number of retrieved (6.4 +/- 2.3 versus. 15.7 +/- 5.4) and fertilized (3.6 +/- 1.6 versus 7.0 +/- 4.5) oocytes differ significantly (P = 0.001) between the two groups. The fertilization rate was significantly higher in G.I than in G.II (60.9 +/- 25.1 versus 43.4 +/- 20.7%).

CONCLUSION

There was no significant difference between IGF-I, IL-6, IL-8, EGF and GM-CSF concentrations of low and high responder patients. Besides, PDGF was significantly (P = 0.007) higher in high responder compared with low responder patients. Moreover, in poor responder patients, a negative correlation was found between PDGF and fertilization rate. However, the cytokine levels in FF of the patients undergoing controlled ovarian hyperstimulation for ICSI could not be used as a marker of oocyte fertilization and implantation potential.

Expression of insulin-like growth factor (IGF), IGF receptor, and IGF-binding protein messenger ribonucleic acids in luteinized granulosa cells from different size follicles after controlled ovarian hyperstimulation

PURPOSE

This study was conducted to determine the gene expression of insulin-like growth factors (IGFs), their receptors, and binding proteins (IGFBPs) in human luteinized granulosa cells collected during ovum retrieval.

METHODS

cDNA probes were used to analyze the gene expression of IGF-I, IGF-II, IGF type 1 receptor (IGFR-1), IGF type 2 receptor (IGFR-2), and IGFBP-1 to -6 in luteinized granulosa cells.

RESULTS

The levels of IGFBP-5 transcripts of the luteinized granulosa cells increased with increasing follicular fluid (FF) volume when follicles were grouped into 3 volume catagories of < or = 1.5 mL: > 1.5 mL but < or = 4.5 mL; and > 4.5 mL (0.28 +/- 0.64 vs. 0.41 +/- 0.76 vs. 0.46 +/- 0.92, p = 0.037).

CONCLUSIONS

The increased levels of IGFBP-5 transcripts in luteinized granulosa cells found with increased follicular fluid volume after COH may favor a shift toward diminished action of IGFs in larger follicles immediately prior to ovulation.

Cyclic changes in serum levels of insulin-like growth factor binding protein-1 in women treated with clomiphene citrate and tamoxifen

In order to investigate the cyclic changes of serum insulin-like growth factor-I (IGF-I), IGF binding protein-1 (IGFBP-1) and IGFBP-3 levels in menstrual cycles treated with or without antiestrogens (clomiphene citrate and tamoxifen), we treated 24 young women having irregular menstrual cycles with either clomiphene citrate (100 mg/day) (n = 12) or tamoxifen (60 mg/day) (n = 12) from the 5th to the 9th day of the menstrual cycle. Without antiestrogens, 12 women with regular menstrual cycles were recruited as controls. There was a preovulatory (day 13) peak of circulating IGFBP-1 in women treated with or without antiestrogens. A significant concomitant increase in serum estradiol was also observed on day 13 of the menstrual cycle in subjects treated with clomiphene citrate and in controls. However, no significant elevation in preovulatory estradiol was detected in women treated with tamoxifen. In clomiphene citrate and control groups, a significant positive correlation was found between circulating IGFBP-1 and estradiol, and between serum levels of IGFBP-1 and inhibin A at the preovulatory stage (on day 13). In contrast, no such association was observed in the tamoxifen group. Unlike cyclic changes in circulating IGFBP-1, serum concentrations of IGF-I and IGFBP-3 remained unchanged throughout the menstrual cycle in all groups. In conclusion, the preovulatory peak of circulating IGFBP-1 can be induced in cycles treated with both clomiphene citrate and tamoxifen. In addition, a significant positive correlation between estradiol, inhibin A and IGFBP-1 at the preovulatory stage indicates that IGFBP-1 may also reflect follicular development and may further be used as an additional indicator to monitor folliculogenesis under clomiphene citrate treatment.

Serum levels of insulin-like growth factor I and insulin-like growth factor-binding protein-1 and -3 in women with regular menstrual cycles

OBJECTIVE

To investigate the cyclic changes of serum insulin-like growth factor (IGF-I), IGF-binding protein-1 (IGFBP-1) and IGFBP-3 levels during ovulatory menstrual cycle.

DESIGN

A prospective study following a preset protocol.

SETTING

A tertiary-care academic medical center.

PARTICIPANTS

Thirty young female adults with regular menstrual cycles were recruited (18 with normal luteal phase and 12 with inadequate luteal function confirmed by serum P levels).

MAIN OUTCOME MEASURES

Serum concentrations of IGF-I, IGFBP-1, and IGFBP-3 from women with regular menstrual cycles were assayed. Circulating E2 and P levels also were determined to certify the ovulatory cycles.

RESULTS

In women with normal luteal function, there was a peak of serum IGFBP-1 levels before ovulation concomitant with the preovulatory E2 peak. The nadir of serum IGFBP-1 levels was in the midluteal phase. Circulating IGFBP-1 elevated rapidly during late luteal phase and reached a peak on the 1st day of menstruation then declined slightly until a preovulatory IGFBP-1 peak occurred. In women with inadequate luteal function (midluteal serum levels of P < 10 ng/mL [conversion factor to SI unit, 3.180]), the preovulatory increase in serum IGFBP-1 was not significant and the circulating IGFBP-1 levels fluctuated throughout the menstrual cycle except for a unique peak of serum IGFBP-1 on the 1st day of menstruation. By contrast, there were no cyclic changes of serum IGF-I and IGFBP-3 levels in women with regular menstrual cycles, including both normal nad inadequate luteal functions.

CONCLUSIONS

The preovulatory increase in serum IGFBP-1 levels may be of follicular origin and associated with the subsequent luteal function in females with ovulatory cycles. However, the involvement of IGFBP-1 in the process of follicular maturation and luteogenesis, as well as the regulation of luteal function, needs to be explored further.