Deciding ICSI vs Conventional Insemination Based on Semen Analysis
Sperm concentration and morphology appear to be the most predictive indicators of the optimal method of fertilizing oocytes. We can study this best in split cycles where half of the oocytes are fertilized with ICSI (IntraCytoplasmic Sperm Injection) and half with conventional insemination. We then look to see which method produced the most embryos (measured as day 5 blastocyst equivalents per oocyte).
We can assign a value of 0.5 if ICSI and conventional insemination had equal performance (equal number of day 5 blastocyst equivalents obtained per oocyte). A value of 1 is given if all of the embryos obtained in a split cycle were obtained from the ICSI group and a value of 0 if all of the embryos obtained were from the conventional insemination group.
In this dataset the average sperm morphology was 5%. Data are not expected to be appliable to andrology labs that do not have an average reporting morphology of 5% since semen analysis reporting ranges vary by lab. Our center has data on approximately 35 split cycles using 1/2 ICSI and 1/2 conventional insemination.
Predicted optimal method of fertilization.
We can then summarize the data and give some preference to conventional insemination to account for uncertainty in the data and the fact that ICSI adds approximately an additional $1,500 to $2,200 cost to the cycle as an add on procedure. For concentration under 25 million per mL there are low numbers and ICSI is slightly favored so those are left as ICSI best based on a combination of the data and clinical intuition.
Embryo grading key.
We also want to examine if the rate of ongoing pregnancy is the same for embryos created from ICSI and conventional insemination.
For this we have evaluated ongoing pregnancy rates for frozen embryo transfers of non PGT tested embryos. The expected rate of fetal heartbeat per embryo is taken from a published reference standard on live birth rate based on embryo morphology and day of blastocyst formation (1). The expected fetal heartbeat rate per embryo is the expected live birth rate divided by 0.93 (this is a standard conversion we commonly use).
For example a day 5 blastocyst from someone 33 years old at retrieval has an expected live birth rate of 40% and an expected rate of fetal heartbeat of 43%.
We don’t find any difference in fetal heartbeat rate for ICSI compared to conventional insemination. The average patient age was 31 years old. 59% of embryos were frozen on day 5, 38% on day 6, and 3% on day 7.
This research has been approved by the Christ Hospital IRB (protocol #25-030)
(1) Awadalla MS, Ho JR, McGinnis LK, Ahmady A, Cortessis VK, Paulson RJ. Embryo morphology and live birth in the United States. F&S Reports. 2022 Jun 1;3(2):131-7