['This study is to assess whether transient intrauterine fluid accumulation (IUFA) first noted during controlled ovarian hyperstimulation that does not persist on the day of embryo transfer not due to any identifiable pelvic pathology has any detrimental effect on in vitro fertilization (IVF) outcome.', 'From a database of 16,900 cycles, 144 patients with transient "physiological" IUFA were recruited. Four hundred fifty-one consecutive patients who had male factor infertility served as the control group. The amount of IUFA classified as largest dimension in the antero-posterior (AP) plane; ≤2, 3-5 or >5\xa0mm.', 'The mean female age, the mean number of embryos transferred and endometrial thickness on the day of hCG administration were comparable among the study and control groups. Similarly, clinical pregnancy, ongoing pregnancy and implantation rates were comparable among the study and control groups. Female age was noted to be the only significant independent predictor of ongoing pregnancy. The AP dimension of IUFA did not have any impact on pregnancy and implantation rates.'] Is transient intrauterine fluid accumulation not due to hydrosalpinx or any identifiable pelvic pathology detrimental to IVF outcome?