Comparison of 2 Different Flow Rates During Oocyte Retrieval

Is Flow Rate During Oocyte Retrieval Associated With the Number of Oocytes Retrieved? A Randomized Control Trial

The purpose of this study is to evaluate the effect of different flow rates during oocyte retrieval, on the number of cumulus oocyte complexes (COCs) retrieved.

In the current study, each ovary will be randomly allocated to oocyte retrieval using 0.42 ml/sec or 0.62 ml/sec flow rate. The primary endpoint will be the number of oocytes retrieved, while secondary outcomes will include oocyte recovery rate (number of oocytes retrieved per follicle aspirated), number of mature oocytes, maturation rate (number of mature oocytes/number of oocytes retrieved), mean oocyte score (by evaluating oocyte shape and size, ooplasm characteristics, structure of perivitelline space (PVS), structure of zona pellucida (ZP) and polar body (PB) morphology), fertilization rate (number of fertilized oocytes/number of mature oocytes), number of blastocysts and blastulation rate (number of blastocysts/number of 2PN). Patients aged <43 years with the presence of at least 3 follicles ≥ 11mm in each ovary on the day of oocyte retrieval will be eligible for inclusion in the study. Prior to oocyte retrieval in eligible patients their left and right ovary will be randomly allocated into the 0.42 ml/sec or 0.62 ml/sec flow rate group. Randomisation with minimisation will be employed. The specific flow rates will be achieved by adjusting the aspiration pressure of the vacuum pump accordingly. A study nurse will be responsible for adjusting the aspiration pressure of the vacuum pump depending on randomization. The doctor performing the oocyte retrieval will not be aware of the flow rate used in each ovary. All follicles will be aspirated and then flushed if needed up to a maximum of 5 times with an open flushing technique, using a 17G double-lumen needle. Data will be registered regarding the number of flushes required to retrieve a COC, the morphology of oocytes after denudation, oocyte fertilisation and embryo development up to the blastocyst stage.

All follicles will be aspirated with the addition of follicular flushing if necessary with an aspiration flow rate of 0.42ml/sec.

All follicles will be aspirated with the addition of follicular flushing if necessary with an aspiration flow rate of 0.62ml/sec.

All follicles will be aspirated with the addition of follicular flushing if necessary (up to 5 times per follicle) with an aspiration flow rate of 0.42 ml/sec.

High aspiration flow rate All follicles will be aspirated with the addition of follicular flushing if necessary (up to 5 times per follicle) with an aspiration flow rate of 0.62 ml/sec.

Number of mature (metaphase-II) oocytes divided by the number of oocytes retrieved per ovary randomised.

Average oocyte score based on the evaluation of oocyte shape and size, ooplasm characteristics, structure of perivitelline space, structure of zona pellucida and polar body morphology.

Number of fertilised (2PN) oocytes divided by the number of matured oocytes retrieved per ovary randomised.

Inclusion Criteria: Presence of both ovaries 18-43 years old At least two follicles >14mm present in each ovary on day of triggering final oocyte maturation. Exclusion Criteria: One or no ovaries present Monofollicular development Poor responders Previous history of hemorrhage during oocyte retrieval

Lazzaroni-Tealdi E, Barad DH, Albertini DF, Yu Y, Kushnir VA, Russell H, Wu YG, Gleicher N. Oocyte Scoring Enhances Embryo-Scoring in Predicting Pregnancy Chances with IVF Where It Counts Most. PLoS One. 2015 Dec 2;10(12):e0143632. doi: 10.1371/journal.pone.0143632. eCollection 2015.