Ovarian hyperstimulation syndrome (OHSS) is the most serious iatrogenic complication of ovulation induction. The ovaries are noted to have a significant degree of stromal edema, interspersed with multiple hemorrhagic follicular and theca-lutein cysts, areas of cortical necrosis, and neovascularization. Mutations in follicle-stimulating hormone (FSH) receptors could be activating, resulting in OHSS, or inactivating, resulting in sterility. Bone morphogenic protein-15 (BMP-15) appears to be associated with mechanisms of infertility and superfertility in a dosage-sensitive manner. Human chorionic gonadotropin increases vascular endothelial growth factor (VEGF) production by granulosa cells and endothelial cells, which results in increased vascular permeability. Increased intraovarian blood flow and low intravascular ovarian resistance are correlated with the severity of OHSS in patients who develop the syndrome. The medical treatment of OHSS consists of correction of circulatory volume and electrolyte imbalance. Ultrasonographic guidance of transvaginal or transabdominal aspiration of ascites improves the symptoms of patients with OHSS.

This chapter discusses the usefulness of ultrasound in diagnosing normal and abnormal fallopian tubes using two-dimensional (2D) and three-dimensional (3D) transvaginal ultrasonography (TVS) and hysterosalpingo-contrast sonography (HyCoSy). HyCoSy involves the introduction of fluid into the uterine cavity and the fallopian tubes. The role of HyCoSy as a first-line procedure for the assessment of tubal patency has been examined in several studies. In most of the studies, the diagnostic capabilities of HyCoSy have been compared with the established reference methods of hysterosalpingography (HSG) or laparoscopy with dye insufflation, or both, and in the majority of the studies Echovist was used as the ultrasonographic contrast medium. A multicenter study in Scandinavia compared laparoscopic salpingectomy with no intervention prior to the first in vitro fertilization (IVF) cycle. The study demonstrated significant improvement in pregnancy and birth rates after salpingectomy in patients with hydrosalpinges that were large enough to be visible on ultrasound.

In 1869, a hemorrhagic uterine growth was diagnosed and cauterized with silver nitrate, thus qualifying the procedure to be the first operative hysteroscopy during direct visualization of endometrial cavity. The pressure required to separate the walls of a normal-sized uterine cavity (with saline) is less than 50mmHg. A solution containing 35% dextran 70 (molecular weight 70,000 kDa) was introduced as a distending medium for hysteroscopy. Compared with placebo, use of misoprostol among premenopausal women before hysteroscopy was found to result in fewer cervical lacerations, most probably secondary to a reduced need for cervical dilation. Despite the increasing adoption of hysteroscopy as an ambulatory procedure, protocols for local anesthesia and/or analgesia remain far from uniform. In a flexible hysteroscope, fiberoptic bundles (flexible) transmit the image to the eyepiece or the camera. Pregnancy and genital tract infections are obvious contraindications to hysteroscopy.

Currently, ultrasound is the most widely used noninvasive means of evaluating ovarian morphology in women with suspected polycystic ovary syndrome (PCOS). Although the most commonly used diagnostic sonographic features of PCOS are follicle number and ovarian volume, there is no complete consensus regarding the best criteria for ultrasound diagnosis. Transabdominal ultrasound has been largely superseded by transvaginal scanning because of greater resolution and, in many cases, patient preference. The transabdominal route is, of course, required in adolescent girls and virginal women who decline a transvaginal scan. The different ultrasound criteria for diagnosis of PCOS are: anthral follicle count, total ovarian volume, stromal area and ovarian area, stromal echogenicity, and vascularity. The Rotterdam criteria for the diagnosis of PCOs include the presence of 12 or more follicles in each ovary measuring 2-9 mm in diameter and/or increased ovarian volume (greater than 10 ml).

With the advancement of ultrasound (US) technology with introduction of 3D technology as well, detailed examination of the uterine cervix, anatomy, and accurate measurements have become possible. Benign gynecologic conditions seen by US in non-pregnant state include nabothian cysts, cervical polyps, fibroids and Mullerian anomalies. The importance of transvaginal US in diagnosing placenta previa lies also in the ability by transvaginal US to determine exact distance of placental edge from internal os, which will consequently determine mode of delivery. US is the main diagnostic tool for cervical pregnancy. Doppler is a very important tool as well, due to its difficult diagnosis, it should be differentiated from the cervical stage of spontaneous abortion and nabothian cyst and cervical choriocarcinoma. The risks of cervical pregnancy are mainly severe hemorrhage, necessitating hysterectomy in many situations, and it usually occurs in nulliparous or low-parity women, adding to the dilemma of management.