Cytokines hold promise for human embryo culture in vitro: results of a randomized clinical trial

Effects of Melatonin, GM-CSF, IGF-1, and LIF in Culture Media on Embryonic Development: Potential Benefits of Individualization

The implantation of good-quality embryos to the receptive endometrium is essential for successful live birth through in vitro fertilization (IVF). The higher the quality of embryos, the higher the live birth rate per cycle, and so efforts have been made to obtain as many high-quality embryos as possible after fertilization. In addition to an effective controlled ovarian stimulation process to obtain high-quality embryos, the composition of the embryo culture medium in direct contact with embryos in vitro is also important. During embryonic development, under the control of female sex hormones, the fallopian tubes and endometrium create a microenvironment that supplies the nutrients and substances necessary for embryos at each stage. During this process, the development of the embryo is finely regulated by signaling molecules, such as growth factors and cytokines secreted from the epithelial cells of the fallopian tube and uterine endometrium. The development of embryo culture media has continued since the first successful human birth through IVF in 1978. However, there are still limitations to mimicking a microenvironment similar to the reproductive organs of women suitable for embryo development in vitro. Efforts have been made to overcome the harsh in vitro culture environment and obtain high-quality embryos by adding various supplements, such as antioxidants and growth factors, to the embryo culture medium. Recently, there has been an increase in the number of studies on the effect of supplementation in different clinical situations such as old age, recurrent implantation failure (RIF), and unexplained infertility; in addition, anticipation of the potential benefits from individuation is rising. This article reviews the effects of representative supplements in culture media on embryo development.

The impact of using culture media containing granulocyte-macrophage colony-stimulating factor on live birth rates in patients with a history of embryonic developmental arrest in previous in vitro fertilization cycles

Objective:

To investigate the effect of using culture media containing granulocyte-macrophage colony-stimulating factor (GM-CSF) on embryological data and reproductive outcomes in patients with early embryonic developmental arrest.

Material and Methods:

Retrospective case-control study. A total of 39 patients, whose embryos were incubated with culture media containing GM-CSF due to embryonic developmental arrest in two previous in vitro fertilization (IVF) cycles in-between January 2016 and November 2017 at Hacettepe University IVF Center, were enrolled. Control group was generated among patients with first IVF attempts due to tubal factor in the same time period. All embryos in the control group were incubated with single step culture medium (without GM-CSF). For the control group selection, matching was done 1:2 ratio considering female age, body mass index, number of M-II oocyte retrieved, and number of embryo transferred (n=80).

Results:

Demographic features and embryological data were comparable between two groups. Number of fertilized oocytes (2-pronuclear) was 3.7±2.0 in GM-CSF group and 3.9±2.5 in the control (p=0.576). Overall, number of embryos transferred (1.3±0.5 vs 1.3±0.5, respectively) and blastocyst transfer rate (67.6% vs 59.2%, respectively; p=0.401) were similar. For the reproductive outcomes, implantation rate (32.3% vs 33.1%, respectively; p=0.937), clinical pregnancy rate (33.3% vs 32.5%, respectively; p=0.770), and live birth rate (25.2% vs 26.2%, respectively; p=0.943) were similar.

Conclusion:

Using GM-CSF-containing culture media in patients with two previous failed IVF attempts due to embryonic developmental arrest might rectify embryological data and reproductive outcomes. To make solid conclusion further randomized controlled trials are warranted.

A combination of growth factors and cytokines alter preimplantation mouse embryo development, foetal development and gene expression profiles

Within the maternal tract, the preimplantation embryo is exposed to an array of growth factors (GFs) and cytokines, most of which are absent from culture media used in clinical IVF. Whilst the addition of individual GFs and cytokines to embryo culture media can improve preimplantation mouse embryo development, there is a lack of evidence on the combined synergistic effects of GFs and cytokines on embryo development and further foetal growth. Therefore, in this study, the effect of a combined group of GFs and cytokines on mouse preimplantation embryo development and subsequent foetal development and gene expression profiles was investigated. Supplementation of embryo culture media with an optimised combination of GFs and cytokines (0.05 ng/ml vascular endothelial GF, 1 ng/ml platelet-derived GF, 0.13 ng/ml insulin-like GF 1, 0.026 ng/ml insulin-like GF 2 and 1 ng/ml granulocyte colony-stimulating factor) had no effect on embryo morphokinetics but significantly increased trophectoderm cell number (P = 0.0002) and total cell number (P = 0.024). Treatment with this combination of GFs and cytokines also significantly increased blastocyst outgrowth area (P < 0.05) and, following embryo transfer, increased foetal weight (P = 0.027), crown-rump length (P = 0.017) and overall morphological development (P = 0.027). RNA-seq analysis of in vitro derived foetuses identified concurrent alterations to the transcriptional profiles of liver and placental tissues compared with those developed in vivo, with greater changes observed in the GF and cytokine treated group. Together these data highlight the importance of balancing the actions of such factors for the regulation of normal development and emphasise the need for further studies investigating this prior to clinical implementation.

GM-CSF (granulocyte macrophage colony-stimulating factor) supplementation in culture media for women undergoing assisted reproduction

BACKGROUND

GM-CSF (granulocyte macrophage colony-stimulating factor) is a growth factor that is used to supplement culture media in an effort to improve clinical outcomes for those undergoing assisted reproduction. It is worth noting that the use of GM-CSF-supplemented culture media often adds a further cost to the price of an in vitro fertilisation (IVF) cycle. The purpose of this review was to assess the available evidence from randomised controlled trials (RCTs) on the effectiveness and safety of GM-CSF-supplemented culture media.

OBJECTIVES

To assess the effectiveness and safety of GM-CSF-supplemented human embryo culture media versus culture media not supplemented with GM-CSF, in women or couples undergoing assisted reproduction.

SEARCH METHODS

We used standard methodology recommended by Cochrane. We searched the Cochrane Gynaecology and Fertility Group Trials Register, CENTRAL, MEDLINE, Embase, CINAHL, LILACS, DARE, OpenGrey, PubMed, Google Scholar, and two trials registers on 15 October 2019, checked references of relevant papers and communicated with experts in the field.

SELECTION CRITERIA

We included RCTs comparing GM-CSF (including G-CSF (granulocyte colony-stimulating factor))-supplemented embryo culture media versus any other non-GM-CSF-supplemented embryo culture media (control) in women undergoing assisted reproduction.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live birth and miscarriage rate. The secondary outcomes were clinical pregnancy, multiple gestation, preterm birth, birth defects, aneuploidy, and stillbirth rates. We assessed the quality of the evidence using GRADE methodology. We undertook one comparison, GM-CSF-supplemented culture media versus culture media not supplemented with GM-CSF, for those undergoing assisted reproduction.

MAIN RESULTS

We included five studies, the data for three of which (1532 participants) were meta-analysed. We are uncertain whether GM-CSF-supplemented culture media makes any difference to the live-birth rate when compared to using conventional culture media not supplemented with GM-CSF (odds ratio (OR) 1.19, 95% confidence interval (CI) 0.93 to 1.52, 2 RCTs, N = 1432, I² = 69%, low-quality evidence). The evidence suggests that if the rate of live birth associated with conventional culture media not supplemented with GM-CSF was 22%, the rate with the use of GM-CSF-supplemented culture media would be between 21% and 30%. We are uncertain whether GM-CSF-supplemented culture media makes any difference to the miscarriage rate when compared to using conventional culture media not supplemented with GM-CSF (OR 0.75, 95% CI 0.41 to 1.36, 2 RCTs, N = 1432, I² = 0%, low-quality evidence). This evidence suggests that if the miscarriage rate associated with conventional culture media not supplemented with GM-CSF was 4%, the rate with the use of GM-CSF-supplemented culture media would be between 2% and 5%. Furthermore, we are uncertain whether GM-CSF-supplemented culture media makes any difference to the following outcomes: clinical pregnancy (OR 1.16, 95% CI 0.93 to 1.45, 3 RCTs, N = 1532 women, I² = 67%, low-quality evidence); multiple gestation (OR 1.24, 95% CI 0.73 to 2.10, 2 RCTs, N = 1432, I² = 35%, very low-quality evidence); preterm birth (OR 1.20, 95% CI 0.70 to 2.04, 2 RCTs, N = 1432, I² = 76%, very low-quality evidence); birth defects (OR 1.33, 95% CI 0.59 to 3.01, I² = 0%, 2 RCTs, N = 1432, low-quality evidence); and aneuploidy (OR 0.34, 95% CI 0.03 to 3.26, I² = 0%, 2 RCTs, N = 1432, low-quality evidence). We were unable to undertake analysis of stillbirth, as there were no events in either arm of the two studies that assessed this outcome.

AUTHORS' CONCLUSIONS

Due to the very low to low quality of the evidence, we cannot be certain whether GM-CSF is any more or less effective than culture media not supplemented with GM-CSF for clinical outcomes that reflect effectiveness and safety. It is important that independent information on the available evidence is made accessible to those considering using GM-CSF-supplemented culture media. The claims from marketing information that GM-CSF has a positive effect on pregnancy rates are not supported by the available evidence presented here; further well-designed, properly powered RCTs are needed to lend certainty to the evidence.