PREGNANCY RATES AFTER THE USE OF OIL-BASED AND WATER-BASED CONTRAST-MEDIA TO EVALUATE TUBAL PATENCY

Hysterosalpingography (HSG) has assumed a diagnostic and possibly therapeutic role in the evaluation of the infertile couple. The procedure is done using either an oil-based (OBCM) or a water-based (WBCM) contrast medium. Data from several retrospective studies suggest that higher pregnancy rates may be achieved when OBCM is used. Interpretation of these results, however, may be confounded by various methodologic flaws in study design and comparisons of heterogeneous populations. We sought to compare the therapeutic benefit of OBCM and WBCM in a prospective randomized study of infertile patients, controlling for pelvic anatomy by laparoscopic assessment. We used ethiodized oil (Ethiodol) or iothalamate meglumine (Conray 60) for tubal lavage at the time of laparoscopy only in patients with normal pelvic anatomy. Of the 225 patients who had diagnostic laparoscopy in the evaluation of infertility, 40 (18%) had normal pelvic anatomy and an otherwise unremarkable evaluation. Adequate follow-up was available on 29 patients randomized to receive either OBCM (n = 15) or WBCM (n = 14). A significant difference in pregnancy rates was noted between OBCM (40%) and WBCM (14%) by chi-square analysis. No short- or long-term adverse reactions were noted. Results of this study suggest that in patients with normal pelvic anatomy as assessed laparoscopically, OBCM may offer a therapeutic benefit not evident with WBCM.