**3. Conclusion**

It is generally accepted that endometriosis and infertility are associated. However, the mechanisms connecting these complex conditions are still elusive. Results of different studies on virtually every aspect of this subject are controversial. Despite controversy, there is general agreement on relatively few final consequences of these pathophysiologic processes - endometriosis impairs the quality of oocytes with resulting lower fertilization rates and/or decreases implantation capacity of embryos (Pellicer et al., 2001).

One of indirect markers of oocyte quality and a possible predictor of embryo's implantation capacity is the quality of the developing embryo. As such, this parameter could be valuable for the assessment of influence of endometriosis on fertility of affected individuals. There are several indicators of embryo quality. Some of them are indirect measures of quality (the number of embryos on Day 2, the number of blastocysts, the number of frozen blastocysts, but also the implantation rate), while the only direct measure is the embryo quality score based on morphological characteristics of a developing embryo.

Our study showed no statistically significant difference of quality score of transferred blastocysts, indirect measures of embryo quality, common outcomes of IVF-ET cycles (implantation rate, clinical pregnancy rate, clinical miscarriage rate, early pregnancy loss rate and live births rate) or other analyzed parameters (male factor present, number of oocytes retrieved, number of fertilized oocytes, fertilization rate method of fertilization) between the group of infertile patients with endometriosis and the group with tubal factor infertility only.

In the further analysis of our data, we also showed that in infertile patients suffering only from endometriosis, embryo quality was a statistically significant positive predictor of positive βhCG measurement (if embryo quality was expressed in the form of embryo quality score, OR=4.278; 95% CI 1.976 - 9.265, P<0.001), clinical pregnancy rate (if embryo quality was expressed in the form of embryo quality score, OR=3.485; 95% CI 1.608 - 7.553, P=0.002) and live births rate (if embryo quality was expressed in the form of number of frozen blastocysts, OR=1.319; 95% CI 1.034 - 1.683, P=0.026). As expected, the patient's age was a statistically significant negative predictor of the success of IVF-ET cycles (positive βhCG measurement, clinical pregnancy rate and live births rate) in the observed group of patients.

Endometriosis is still an insufficiently explained condition. Numerous controversies still surrounding this complex disease indicate an obvious need for further clinical studies, metaanalyses and explanation of its pathophysiologic mechanisms. Should a consensus be reached on a precise methodology, future studies would definitely be more informative and results easier to use in clinical practice.

#### **4. References**

394 Endometriosis - Basic Concepts and Current Research Trends

After controlling for all other independent possible predictors in the multiple logistic regression model, the predictors of the clinical pregnancy rate in patients with endometriosis identified as statistically significant were the embryo quality score (OR=3.485; 95% CI 1.608 - 7.553, P=0.002) and the age of the woman (OR=0.861; 95% CI 0.770 - 0.963,

A univariate logistic regression model indicated that there was a statistically significant correlation between the live births rate and these indirect measures of embryo quality: the number of blastocysts (OR=1.313; 95% CI 1.139 - 1.513, P<0.001), the number of frozen blastocysts (OR=1.402; 95% CI 1.183 - 1.661, P<0.001) and the embryo quality score of transferred blastocyst (in the form of two subgroups: the one with blastocysts of suboptimal quality only and the other with at least one blastocyst of optimal quality) (OR=3.316; 95% CI 1.693 - 6.496, P<0.001). A statistically significant correlation in univariate model was also noted for the age of the woman (OR=0.861; 95% CI 0.780 -

After controlling for all other independent possible predictors in the multiple logistic regression model, the predictors of the live births rate in patients with endometriosis identified as statistically significant were the age of the woman (OR=0.851; 95% CI 0.756 - 0.958, P=0.07) and the number of frozen blastocysts (OR=1.319; 95% CI 1.034 - 1.683,

It is generally accepted that endometriosis and infertility are associated. However, the mechanisms connecting these complex conditions are still elusive. Results of different studies on virtually every aspect of this subject are controversial. Despite controversy, there is general agreement on relatively few final consequences of these pathophysiologic processes - endometriosis impairs the quality of oocytes with resulting lower fertilization

One of indirect markers of oocyte quality and a possible predictor of embryo's implantation capacity is the quality of the developing embryo. As such, this parameter could be valuable for the assessment of influence of endometriosis on fertility of affected individuals. There are several indicators of embryo quality. Some of them are indirect measures of quality (the number of embryos on Day 2, the number of blastocysts, the number of frozen blastocysts, but also the implantation rate), while the only direct measure is the embryo quality score

Our study showed no statistically significant difference of quality score of transferred blastocysts, indirect measures of embryo quality, common outcomes of IVF-ET cycles (implantation rate, clinical pregnancy rate, clinical miscarriage rate, early pregnancy loss rate and live births rate) or other analyzed parameters (male factor present, number of oocytes retrieved, number of fertilized oocytes, fertilization rate method of fertilization) between the group of infertile patients with endometriosis and the group with tubal factor

rates and/or decreases implantation capacity of embryos (Pellicer et al., 2001).

based on morphological characteristics of a developing embryo.

P=0.009).

**2.3.2.2.3** *Live births*

0.950, P=0.03).

P=0.026).

**3. Conclusion** 

infertility only.


Embryo Quality and Pregnancy Outcome in Infertile Patients with Endometriosis 397

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**22** 

*Brazil* 

**Endometriosis and Infertility:** 

**The Role of Oxidative Stress** 

Several reports have supported the concept of reduced fecundity in women with endometriosis (Garrido et al., 2002; 2000). Contradictory data have been reported for in vitro fertilization (IVF) outcomes in patients with endometriosis (Garrido et al., 2002; Garcia-Velasco & Arici, 1999; Kumbak et al., 2008; Fernando et al., 2008). Some studies suggest lower fertilization, implantation, and pregnancy rates in women with endometriosis (Barnhardt et al., 2002; Al-Fadhli et al., 2006), possibly owing to impaired oocyte quality with consequent poor embryo quality, or to endometrial defects or defective interactions between the endometrium and the embryo (Kumbak et al., 2008, Brizek et al., 1995; Pellicer

Oocyte quality depends on proper cytoplasmic and nuclear maturation (Kim et al., 1998), with the latter requiring the presence of normal cell spindles that guide chromosome segregation during meiosis (Wang & Keefe, 2002; Mandelbaum et al., 2004; De Santis et al., 2005; Volarcik et al., 1998; Van Blerkom & Davis, 2001). The cell spindle of the oocyte is extremely sensitive to several factors, including oxidative stress (Liu et al., 2003; Navarro et al., 2004; 2006), which might be involved in the etiopathogenesis of infertility related to endometriosis (Campos Petean et al, 2008; Mansour et al, 2009; Jozwik et al., 1999; Carbone

The oxidative balance of the reproductive female tract depends on some types of free radicals and on different antioxidant mechanisms that neutralize them. There are two major

The ROS have physiological and pathological functions in the female reproductive tract. Fertility problems related to ROS have etiopathogenic factors in common (Agarwal et al., 2005). These reactive species are generated through enzymatic and non-enzymatic organic reactions. Biological reactions, through electron transference or through oxigenase, that use

groups of free radicals: reactive oxygen species and reactive nitrogen species.

**1. Introduction** 

et al., 1995).

et al., 2003).

**2. Reactive Oxygen Species (ROS)** 

Ionara Barcelos1 and Paula Navarro2

*University of Sao Paulo - Ribeirao Preto,* 

*1University of West Parana, Da Vinci - Reproductive Medicine,* 

*2University of Sao Paulo,* 

