A new study published in the New England Journal of Medicine is showing that pregnancy rates after hysterosalpingogram (HSG) procedures may be higher when an oil-based contrast is used compared to when a water-based contrast is used. Increased pregnancy rates after HSG procedures have been reported for many years, but it was unclear whether the type of contrast used made a difference.
This study included over 1100 infertile women who were not at high risk for tubal disease. Half of the group underwent an HSG with oil-based contrast and the other half with water-based contrast. Within 6 months after the procedure, the women in the oil contrast group had a 39.7% ongoing pregnancy rate compared to 29.1% in the water contrast group.
Five other studies tried to answer the same question about contrast media for HSGs in the past. Of those 5 studies, 4 showed it made no difference what type of contrast was used, but the largest one did show a difference. When the data from these 5 studies were pooled in a meta-analysis, the compiled data showed no difference in pregnancy rates with oil contrast vs. water contrast.
So, what does this all mean? Does the type of contrast make a difference or not? In my opinion, it’s still hard to definitively say. I would love to see the results of the pooled data from all 6 studies. My guess is that if the 2 largest studies are showing that oil-based contrast has a higher pregnancy rate, it may be true and is worth examining further.
At Reproductive Partners, we’re committed to providing the highest quality and most up to date care. In fact, one of the physicians in our group was one of the first to recognize that oil-based contrast may have a beneficial effect. So, we’re certainly going to be on the look out to see what the collective data shows. Oil contrast does not come without risks though and it makes the procedure more expensive for patients. If the data shows that the benefits outweigh the risks, we’ll be the first to let you know. Stay tuned. . .