Hysterosalpingogram (HSG)

Introduction

Hysterosalpingography (HSG) is an outpatient fluoroscopy procedure that evaluates the uterine cavity and fallopian tube patency. HSG is commonly performed as part of an infertility evaluation or after placement of contraceptive micro-inserts.
This topic will review the indications for HSG, preparation, technique, and test results. Other methods for assessing the uterine cavity and tubal patency are reviewed separately.

Definition

HSG is the evaluation of the uterine cavity, fallopian tubes, and adjacent peritoneal cavity following the injection of contrast material through the cervical canal. It is performed as a real-time outpatient examination under fluoroscopy with iodinated water-soluble radio-opaque material.

Clinical Applications

Indications

As HSG assesses fallopian tube patency and intrauterine contour, clinical indications for HSG include evaluation of female infertility or suspected uterine anomalies, pre-procedure planning for hysteroscopy, and post procedure assessment following tubal ligation or tubal reversal procedures.

Contraindications

The major contraindications to HSG are pregnancy, active undiagnosed vaginal bleeding, active pelvic infection (even if the patient is receiving antibiotic therapy), and a history of a severe reaction to iodinated contrast. Active menstruation is a relative contraindication. In our practice, we use an algorithm to exclude women with contraindications prior to performing the HSG.

Preprocedure Considerations

Infection

The reported rates of pelvic infection following HSG in five series ranged between 0.3 and 3.4 percent

Analgesia

HSG can be associated with some discomfort, primarily from uterine distention. Patient movement as a result of pain can increase the risk of uterine perforation or suboptimal images, which can increase the radiation exposure. We advise women to use over-the-counter analgesics such as nonsteroidal anti-inflammatory drugs if bothersome uterine cramping occurs on the days following the examination.

Radiation

HSG involves ionizing radiation using real-time fluoroscopy during which selected spot radiographs are acquired. In terms of biological effects of the radiation conferred by HSG, the risk for anomalies in a future embryo and for fatal cancer induction in an exposed woman ages 20 to 29 year are estimated at 2.7 x 10^-5 and 14.5 x 10^-5, respectively. These risks are over one-thousand-fold lower than the background rates of birth defects and of spontaneous cancers in the United States

Findings and Related Diagnoses

Tubes Obstruction

Fallopian tube obstruction is confirmed by absence or partial filling of the fallopian tube with contrast

Cornual Spasm

The cornual portion of the fallopian tube is encased in smooth muscle; muscle spasm can cause transient tubal occlusion and prevent contrast from filling an otherwise patent tube. Spasm is characterized by a rounded smooth cornual margin, whereas cornual occlusion is characterized by pointed or irregular cornual margin, although these changes can be difficult to distinguish definitively

Hydrosalpinx

Hydrosalpinx is defined as fluid-filled dilation of the fallopian tube and is most commonly caused by peri tubal adhesions.