Is hydrosalpinx fluid cytotoxic?

Accumulation of oviductal fluid in the ampullar lumen as a result of occlusion of the infundibulum is referred to as hydrosalpinx. A low pregnancy rate (10%) after in-vitro fertilization (IVF) in hydrosalpinx patients and a relatively high incidence (50%) of abortions during the first trimester suggested that leakage of this fluid into the uterine cavity may exert a cytotoxic effect on the developing embryo. To examine this possibility, we analysed the composition of the hydrosalpinx fluid and tested its effect on human granulosa cells and embryos. Hydrosalpinx fluids and granulosa cells were collected from IVF patients at ovum pick-up. IVF eggs containing three pronuclei (3PN) were employed for this study. Analysis of hydrosalpinx fluids revealed electrolyte concentrations similar to those in serum with lower amounts of total protein and albumin. No blood cells were detected and bacterial cultures were negative. Granulosa cells incubated in hydrosalpinx fluid-containing medium (diluted 1:1) were not morphologically different and showed a steroidogenic capacity that was higher than that of cells incubated in its absence. Fertilized 3PN eggs incubated in IVF culture medium successfully developed into 6- to 8- and 8- to 16-cell embryos within 48 and 72 h, respectively. This rate of embryonal development was not impaired by hydrosalpinx fluid (at either 50 or 100% concentration). In the absence of a demonstrable detrimental effect we suggest that the low implantation rate in hydrosalpinx IVF patients may not be due to an embryotoxic effect. We further suggest that constant passage of fluid into the uterine cavity in these patients could possibly introduce some mechanical interference that may result in implantation failure.