Polyvinylpyrrolidone can prevent oolemma lysis caused by abnormal rupture of the plasma membrane in Piezo-ICSI.

The aim of this study was to investigate whether it is possible to prevent oolemma lysis after Piezo-assisted intracytoplasmic sperm injection (Piezo-ICSI) caused by abnormal membrane rupture. A total of 489 mature oocytes were obtained from 85 patients who underwent Piezo-ICSI in an infertility clinic. Inseminated oocytes were classified into the following two groups: normal rupture and abnormal rupture, and a portion of abnormally ruptured oocytes was randomly exposed to 7% PVP solution. Normal fertilization rate, degeneration rate, proportion of high-quality embryos on day 3, blastocyst formation, and morphologically high-quality blastocysts were compared. Abnormal rupture was defined as cytoplasmic membrane rupture before piezo pulse driving. Among the abnormal rupture groups, the normal fertilization and degeneration rates were compared between the high-stretched (ruptured at ≥ 50% during oocyte membrane stretching) and low-stretched (< 50% position) oocytes.The degeneration rate was significantly higher in abnormally ruptured oocytes than in normally ruptures oocytes (14.3% vs 1.3%, p < 0.001), and there was no significant difference in embryonic development after fertilization. PVP treatment immediately after oolemma rupture significantly decreased the degeneration rate (6.0% vs 19.7%, p = 0.031) and increased the normal fertilization rate. Similarly, there were no significant differences in the developmental potential. Furthermore, pregnancy outcome data showed no significant differences in pregnancy and live birth rates. The degeneration rate was reduced by treating low-stretched oocytes with PVP.Exposure to polyvinylpyrrolidone (PVP) immediately after abnormal membrane rupture represents an effective strategy to prevent oocyte degeneration. This is the first study to propose a strategy for the prevention of oocyte degeneration in Piezo-ICSI. These findings are expected to reduce the oocyte degeneration rate and increase normal fertilization rate as well as assist patients who can only acquire oocytes with weak plasma membranes.

Cancellation of in vitro fertilization treatment cycles predicts treatment outcome in female infertility patients aged 40 years or older.

Purpose: To investigate potential indicators of in vitro fertilization (IVF) treatment outcome for female infertility patients aged ≥ 40 years based on the clinical course. Methods: We retrospectively examined results of 111 female infertility patients aged ≥ 40 years undergoing IVF treatment. We investigated the relationship between treatment cycle cancellation and the final outcome of IVF treatment in female infertility patients aged ≥ 40 years. Results: A total of 44 pregnancies were achieved. Overall pregnancy rate per initiated treatment cycle was 12.1%, and 24 spontaneous abortions occurred (54.5%). No woman aged ≥ 45 years achieved pregnancy. No patients conceived after 10 treatment cycles while 42 (11.5%) oocyte pick-up cycles and 120 (33.0%) embryo transfer cycles were canceled. Investigation of correlation with treatment cycle cancellation revealed that patients who experienced embryo transfer cancellation had a high spontaneous abortion rate while only a few patients who experienced oocyte pick-up cancellation achieved pregnancy and even fewer achieved a successful outcome. Conclusions: Our study suggests that, in addition to patient age and number of treatment cycles, cancellation of treatment cycle also provides another useful indicator for pregnancy outcome.