Assessment of Endometrial Thickness & Subendometrial Perfusion by 3D Power Doppler in Women With Unexplained Infertility and PCOS.

• Background Infertility is a frustrating disease that affects many couples around the world. Although there are many etiologies responsible for infertility , there are about 15-30 % of couples who suffer from what is called "Unexplained Infertility". About 25% of infertility is caused by ovulatory disorders. The World Health Organization (WHO) classifies these ovulatory disorders into 3 groups. Group II includes women with hypothalamic-pituitary-ovarian dysfunction (predominately polycystic ovary syndrome (PCOS)) In unexplained infertility, basic investigations that are done first to reveal the cause of infertility reveal normal findings. These basic investigations should provide evidence of ovulation, adequate sperm production and patency of the fallopian tubes.

However, with these routine investigations and even with other more sophisticated investigations it is hard to reveal all possible abnormalities. Therefore, unexplained infertility appears to represent either the lower extreme of the normal distribution of fertility, or it arises from a defect in fecundity that cannot be detected by the routine infertility evaluation. Couples with unexplained infertility suffer from both diminished and delayed fecundity.

Due to absence of specific abnormality in cases with unexplained infertility, the management is usually empiric. Suggested treatment regimens include intrauterine insemination (IUI), ovulation induction with oral or injectable medications, combination of IUI with ovulation induction, and assisted reproductive technologies (ART).

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder affecting young women of reproductive age with the prevalence ranging between 2% to 18% according to different population and diagnostic criteria. It has been suggested that uterine blood flow is impaired in women with PCOS.

Ovulation induction (OI) is by far the most commonly used treatment for women with WHO group II anovulation and clomiphene citrate (CC) has historically been the most used drug In many fertility guidelines, CC is recommended as the first-line treatment for women with group II anovulation or PCOS who wish to conceive. However, other guidelines recommend both CC and letrozole as first-line treatments. It is hypothesized that CC resistance and failure are related to anti-estrogenic effects of CC on the endometrium, cervical mucus, and uterine blood flow.