Reply: Higher reported rates of intravasation of oil-soluble contrast media-there may be a silver lining.

Sir,

We thank Dr Peart for her interest in our article (Roest ). Dr Peart comments that due to the physical and chemical properties of water-based contrast (Peart, 2020), intravasation is less detected with water-based contrast as compared to oil-based contrast media. We agree that the actual intravasation rate after HSG procedures with the use of water-based contrast is presumed to be higher than currently detected, mainly due to the lower iodine concentration of water-based contrast as compared to oil-based contrast. The actual intravasation rate after HSG procedures with water-based and oil-based contrast is likely to be the same. However, it is important to realize that, besides fluoroscopy screening, no additional diagnostics such as blood tests are available to identify intravasation of water-based contrast after an HSG procedure.

Contrary to water-based contrast, oil-based contrast enters the blood circulation as droplets due to its hydrophobic qualities, which might cause oil-embolisms (Uzun ). Be that as it may, our survey showed no sequelae of intravasation of oil-based or water-based contrast in more than 5000 HSGs. The use of fluoroscopy screening during HSG has probably contributed to the prevention of clinical consequences of intravasation, as HSG procedures could be promptly terminated when intravasation was seen.

Conflict of interest

I.R. reports receiving travel fee for presenting at the ASRM 2019 from Guerbet. V.M. reports grants and personal fees from Guerbet. M.B. and C.K. have nothing to disclose. B.W.M. is supported by a NHMRC Practioner Fellowship (GNT1082548). B.W.M. reports personal fees from ObsEva, Merck KGaA, Guerbet, and from iGenomix.