 Introduction/Background Overall, infertility affects about 15.5% of women [1]. Infertility investigations are generally initiated after 12 months of unprotected intercourse without resultant pregnancy in women <35 years of age, whereas they are initiated after 6 months of unprotected intercourse without pregnancy in women >35 years of age. An investigation may commence sooner in couples with a known condition or medical history predisposing to infertility. The most common known causes of infertility are male factor (26%), ovulatory failure (21%), and tubal damage (14%), although in 28% of couples infertility remains unexplained [2]. Female-specific causes of infertility include deterioration of oocyte quality with increasing maternal age; ovulatory disorders, most notably polycystic ovarian syndrome (PCOS); history of salpingitis, such as that caused by chlamydia infection; endometriosis; and uterine cavity abnormalities interfering with implantation causing inability to become pregnant or causing recurrent pregnancy loss [3]. These potential causes of female infertility will be discussed here. Imaging can be used to count ovarian follicles and help determine ovarian reserve, particularly in advanced maternal age. Imaging can also be useful in diagnosing polycystic ovarian morphology (PCOM) in women suspected of having PCOS. PCOS is the leading cause of anovulatory infertility, affecting at least 7% of adult women [4]. Women with PCOS experience hyperandrogenism, infertility, and have PCOM defined as >25 small follicles in at least one ovary or a single ovarian volume >10 mL on transvaginal ultrasound (TVUS) [5]. Because PCOM may be present in up to one-third of reproductive-aged women [6], the imaging findings of PCOM are not sufficient for the diagnosis of PCOS but serve to support the diagnosis of PCOS in women with the clinical features. Endometriosis affects at least one-third of women with infertility and up to 10% of reproductive-aged women [7].
Female Infertility.  Introduction/Background Overall, infertility affects about 15.5% of women [1]. Infertility investigations are generally initiated after 12 months of unprotected intercourse without resultant pregnancy in women <35 years of age, whereas they are initiated after 6 months of unprotected intercourse without pregnancy in women >35 years of age. An investigation may commence sooner in couples with a known condition or medical history predisposing to infertility. The most common known causes of infertility are male factor (26%), ovulatory failure (21%), and tubal damage (14%), although in 28% of couples infertility remains unexplained [2]. Female-specific causes of infertility include deterioration of oocyte quality with increasing maternal age; ovulatory disorders, most notably polycystic ovarian syndrome (PCOS); history of salpingitis, such as that caused by chlamydia infection; endometriosis; and uterine cavity abnormalities interfering with implantation causing inability to become pregnant or causing recurrent pregnancy loss [3]. These potential causes of female infertility will be discussed here. Imaging can be used to count ovarian follicles and help determine ovarian reserve, particularly in advanced maternal age. Imaging can also be useful in diagnosing polycystic ovarian morphology (PCOM) in women suspected of having PCOS. PCOS is the leading cause of anovulatory infertility, affecting at least 7% of adult women [4]. Women with PCOS experience hyperandrogenism, infertility, and have PCOM defined as >25 small follicles in at least one ovary or a single ovarian volume >10 mL on transvaginal ultrasound (TVUS) [5]. Because PCOM may be present in up to one-third of reproductive-aged women [6], the imaging findings of PCOM are not sufficient for the diagnosis of PCOS but serve to support the diagnosis of PCOS in women with the clinical features. Endometriosis affects at least one-third of women with infertility and up to 10% of reproductive-aged women [7].