Tubal flushing debated at ESHRE

No benefit was found for earlier flushing of the fallopian tubes with oil-based contrast, in a study of women with unexplained infertility and good prognosis. 

Hysterosalpingography is a type of X-ray of the uterus used nominally for visualisation of the reproductive organs to help with diagnosis, but it has also been shown to have some positive effect on pregnancy rates in people with infertility. It is assumed the contrast medium placed in the uterus to help with imaging, can flush out debris that may be infringing on conception in the fallopian tubes. 

In a non-peer-reviewed Danish prospective cohort study of 577 women, participants were either assigned to have hysterosalpingography carried out early in infertility investigations, or six months later. Researchers from Denmark found this had no effect on fertility or pregnancy outcomes or time taken to conceive. 

'We were also a little bit surprised with the results I have to say,' said Danah Kamphuis, a PhD candidate at Amsterdam University Medical Centre in the Netherlands who presented the research at the 40th annual meeting of the European Society of Human Reproduction and Embryology (ESHRE) in Amsterdam on Monday 8 July 2024.

Professor Neil Johnson, a member of the audience and fertility specialist and past president of the World Endometriosis Society flagged his own previous research into the procedure which had shown efficacy in women without favourable prognosis, including those with endometriosis, who are at higher risk of problems in the fallopian tubes. Kamphuis responded: 'We selected a population with a high chance of becoming pregnant naturally so it is probably a population who doesn't need any intervention at this stage.'

The study also identified thyroid dysfunction in around 17 percent of this cohort who received hysterosalpingography, though most of these cases were sub-clinical.

The following presentation at ESHRE, by Li Yan, resident physician at International Peace Maternal and Child Health Hospital, Shanghai, China outlined the findings of a prospective cohort study comparing the benefits of oil-based and water-based contrast in Chinese women. 

Researchers recruited 569 women with infertility to receive oil-based contrast for their hysterosalpingography and 618 to receive water-based contrast. Their non-peer-reviewed results showed that the rate of women who had a pregnancy lasting at least 20 weeks, was higher in the women who received oil-based contrast, echoing the findings of a previous study of a cohort in the Netherlands. 

Participants were split into subgroups for further analysis, including those at high risk of infertility due to tubal disease caused by endometriosis, previous infections or surgery, and those at lower risk. They found oil-based contrast improved pregnancy rate and live birth rate in women with unexplained fertility. However, this benefit was not shown in women with a high risk of infertility.