The aim of this work is to assess the value of hysteroscopy in unexplained infertility.

The diagnosis of unexplained infertility is one of exclusion and is made only after an infertility evaluation has failed to reveal abnormalities. There is no consensus on which tests should be performed before making this diagnosis (Salim et al., 2011).

The Europe society for human and embryology (ESHRE) suggested standard diagnostic tests for infertility evaluation. These tests include semen analysis, demonstration of tubal patency by hystosalpingography (HSG) or laparascopy and laboratory assessment of ovulation (Polisseni et al., 2003). Moreover post coital test has been included by some authors as a fundamental requirement before the diagnosis of unexplained infertility while other authors found that it is unnecessary however conducting additional investigation and treating any abnormalities detected may be effective in management of women with unexplained infertility especially in older couples (Wortman et al., 2013).

For evaluation of the uterine cavity, the basic work-up consists of transvaginal sonography (TVS) with or without the use of saline or gel as a contrast medium, possibly followed by either HSG or hysteroscopy to directly assess the uterine cavity.

Both TVS, as well as saline infusion sonography (SIS) and gel instillation sonography (GIS) are inexpensive, non-invasive and have been shown to be excellent diagnostic tool to detect subtle intrauterine abnormalities (Rodrigues et al., 2014).

However, hysteroscopy allows direct visualization of the endometrial lining and detects multiple lesions and subtle uterine abnormalities that cannot be identified by the previous techniques. Moreover, hysteroscopy enables treatment of small uterine pathology in the same setting. Therefore, it is frequently referred to as the golden standard. Many studies have concluded that whenever laparoscopy is performed, it should be combined with hysteroscopy in order to complete the assessment before starting the infertility treatment (Chan et al., 2011).

In the assisted reproductive technique, a number of studies was conducted on women before in vitro fertilization (IVF) cycle revealed that the prevalence of un suspected intra uterine abnormalities, diagnosed by hysteroscopy prior to IVF cycles was 11% - 45% (Shokeir et al., 2011).

Although the role of these subtle lesions as a cause of infertility is debatable,( Kilic et al., 2013) hysteroscopic assessment and treatment of any abnormalities detected has improved the clinical pregnancy rate , live birth, and considered cost effective before IVF cycles (Grimbizis et al., 2003) .

It is widely accepted that a complete infertility workup includes an evaluation of the uterine cavity (Chan et al., 2011). Uterine abnormalities, congenital or acquired, are implicated as one of the causes of infertility. In fact, infertility related to uterine cavity abnormalities has been estimated to be the causal factor in as many as 10% to 15% of couples seeking treatment (Romani et al. 2013).

Hysteroscopy enables visualisation of the uterine cavity and allows the diagnosis and surgical treatment of intrauterine pathology. (Umranikar et al., 2016). Direct view of uterine cavity offers a significant advantage over other blind or indirect diagnostic methods. Although , hystrosalpingography (HSG) is reported to be as accurate as hysteroscopy in the diagnosis of normal and abnormal cavities, the nature of intrauterine filling defects is more accurately revealed by hysteroscopy (Jenneke et al.,2013).

The role of hysteroscopy in infertility investigation is to detect possible intrauterine change that could interfere with implantation or growth, or both, of the conceptus (Scholten et al., 2013) and to evaluate the benefit of direct treatment modalities in restoring a normal endometrial environment (Prasanta et al., 2013).

Several studies have been also performed to find out that if hystroscopic treatment of intrauterine pathologies increases the cause of failure of IVF-ET (Fatemi et al., 2010) and therefore hysteroscopy should be a part of infertility workup for all patients prior to undergoing IVF treatment and have also recommended screening of the uterus by hysteroscopy before proceeding with IVF/ICSI, to minimize implantation failure (Ryan et al. 2005).

The potential risk of diagnostic hysteroscopy are rare in most series (0-1%) especially in office procedure (John et al., 2013), while (5-24%) of operative cessions may result in intraoperative or early postoperative complications which include infection, bleeding, and even perforation of the uterus. Certain factors are considered contraindication to hystroscope like PID (Aydeniz et al., 2004).

Inclusion Criteria:

• 1. All women aged (20-35) years old. 2. Unexplained infertility

Exclusion Criteria:

• 1. Female genital tract cancer, including cervical or uterine cancer 2. Active pelvic infection 3. Known uterine factor for infertility.