VANCOUVER – Ongoing pregnancies and live births were substantially higher when oil-based contrast, instead of water-based contrast, was used for hysterosalpingography (HSG) in a randomized trial at 27 hospitals in the Netherlands.
It’s long been known that HSG, commonly used to assess reproductive tract patency, also improves fertility, perhaps by immunologic effects or simply by flushing debris and mucus out of the fallopian tubes. Until now, however, it’s been unclear if oil or water contrast boosts fertility the most.
To find out, investigators randomized 554 infertile women scheduled for HSG to poppy seed oil contrast (Lipiodol Ultra-Fluid, Guerbet) and 554 others to water contrast (Telebrix Hystero, Guerbet).
A total of 220 women in the oil group (39.7%), but 161 in the water group (29.1%), achieved ongoing pregnancies (rate ratio in favor of oil, 1.37; 95% CI, 1.16-1.61; P less than 0.001). Of 552 women in each of the groups, 214 in the oil group (38.8%) and 155 in the water group (28.1%) had live births (RR, 1.38; 95% CI, 1.17-1.64; P less than 0.001). Rates of adverse events were low and similar in the two groups. About three-quarters of the pregnancies were naturally conceived, and most of the rest resulted from intrauterine insemination. Only a few women in each group used in vitro fertilization (N Engl J Med. 2017 May 18. doi: 10.1056/NEJMoa1612337).
Three women in the oil group, but none in the water group, delivered a child with a congenital anomaly. “This finding is probably due to chance. The frequency of congenital anomalies with oil contrast was not greater than rates reported in the general population, and we are unaware of other data suggesting an increased risk of congenital anomalies with oil contrast,” the researchers said.
In an interview at the World Congress on Endometriosis, senior investigator Ben Mol, MD, PhD, a professor of obstetrics and gynecology at the University of Adelaide (Australia), shared his thoughts on how the new findings should be used in routine practice when women with endometriosis and other conditions experience difficulty conceiving.
There was no industry funding for the work. Dr. Mol reported personal fees from Guerbet unrelated to the study.