Hysterosalpingogram (HSG) is the traditional method used in the evaluation of the infertile patient and provides extensive information about the endometrial cavity as well as the fallopian tubes. Advantages of an HSG include evaluation of the endometrial cavity with good sensitivity (i.e. presence of myomas, polyps, intrauterine adhesions, congenital anomalies), the fallopian tubes (i.e. proximal or distal block, presence of tubal rugae, adhesions), and the possibility of a spontaneous pregnancy following the procedure. The disadvantages include the risk of infection (1-3%), abdominal pain, radiation exposure (very low) and low specificity for intrauterine pathology (polyp vs. myoma; generally does not change the management).
Water or oil based contrast material can be used to perform an HSG, and is a topic of debate regarding the advantages and disadvantages of one over the other. Results of a meta-analysis that included 6 randomized and 6 non-randomized clinical trials concluded that oil based media can have a therapeutic value. Oil-based media was superior over water based media in increasing pregnancy rates after an HSG (OR=1.92, CI: 1.60-2.29). However, a subsequent large, randomized controlled trial did not find any difference between the two media used. Today most centers use water based media, which may provide additional information about intraluminal pathology and pelvic adhesions over the oil-based media.