The aim of this study to assess the follicular fluid level of coenzyme Q10 in women undergoing intracytoplasmic sperm injection (ICSI) and its impact on pregnancy outcome.

ICSI was first applied to human gametes in 1988, it was first used in cases of fertilization failure after standard IVF or when few sperm cells were available. The first pregnancies were reported in Belgium in 1992.It is a part of an in vitro fertilization (IVF) cycle and refers to a technique in which a single sperm is injected directly into the cytoplasm of a mature oocyte (Palermo et al.,1992).

Oocyte quality remains the most important issue during in vitro fertilization (IVF) cycles, it is affected mainly by age of woman and ovarian reserve (Trifunovic et al., 2004).

Oocyte maturation is a complex process including nuclear and cytoplasmic components. Mitochondria which is in the cytoplasm is the key regulator of energy production via oxidative phosphorylation process which is extremely important in oocyte maturation process. Any problem during oxidative phosphorylation might affect both the quality and DNA content of the oocytes (Ben-Meir et al., 2015).

Oxidative phosphorylation involves the action of the mitochondrial respiratory chain which consists of four complexes that are located in the inner mitochondrial membrane (May-Panloup et al., 2007). These are the NAD-linked dehydrogenase, Flavoproteins, Co-enzyme Q10, and cytochromes. Coenzyme Q10 (Ubiquinone) is structurally similar to vitamin E and vitamin K. It acts as a carrier of proton (H+) from flavoproteins to cytochrome (Bentinger et al., 2007).

Coenzyme Q10 is essential for stability and action of complex III (May-Panloup et al., 2007). It also participates in the transport of protons in the mitochondria to maintain the membrane potential and drive ATP formation through ATP synthetase so it has a critical role in cell growth and energy metabolism. One of the most important factors during oogenesis and oocyte maturation is energy consumption so CoQ10 was reported to improve development, hatching, cell proliferation, and ATP content of in vitro-produced bovine embryos (Gendelman et al., 2012; Stojkovic et al., 1999).

Coenzyme Q10 is a commonly used antioxidant supplement in multiple clinical conditions like diabetes, cancer, and cardiovascular diseases. Also, it was shown that Coenzyme Q10 improves sperm motility, semen quality, and pregnancy rate (Garrido-Maraver et al., 2014). Recently Bentov et al. reported that the use of coenzyme Q10 supplementation resulted in reduced aneuploidy and increased pregnancy rate however it is not clinically significant (Bentov et al., 2014).

Several studies reported that pretreatment with CoQ10 could improve ovarian response to stimulation and embryological parameters in women with poor ovarian reserve in IVF-ICSI cycles, however their results are conflicting so further work is needed to determine whether there is an effect on clinical endpoints (Akarsu et al., 2017). In our study we will investigate the relationship between follicular fluid level of Coenzyme Q10 and clinical pregnancy rate (Xu et al., 2018).

Inclusion Criteria:

1. Patient age 20-42 years.
2. Normal and Poor responders women undergoing ICSI procedure.

Exclusion Criteria:

1. Hyper responder patients as polycystic ovarian syndrome (PCOs) patients.
2. Endocrine or metabolic diseases including hyperprolactinoma, hypothyroidism and hyperthyroidism, DM and adrenal disease
3. Patients with severe male factor or Y chromosome abnormality.
4. Patients with systemic disease such as chronic renal disease, chronic liver disease and systemic lupus disease.
5. patients with uterine cavity pathology or abnormality (endometrial polyp, myoma, hyperplasia, congenital abnormality) detected by trasvaginal 3-dimentional ultrasound or office hysteroscopy.

This work will be conducted on normal and poor responder women undergoing ICSI procedure in ART unit in Obstetrics and Gynaecology department, South Valley University hospital female patient aged 20-42 years.

poor responders have at least 2 of the following features:

1. advanced maternal age (40 years or more).
2. previous poor ovarian response (3 or less oocyte retrieved following stimulation).
3. abnormal ovarian reserve teseting (AFC 5-7 or AMH 0.5-1).