In a nutshell
This trial compared intracytoplasmic sperm injection (ICSI) to conventional in vitro fertilization (IVF) for couples where men have normal sperm quality. It found there was no clear benefit to ICSI over IVF for these couples.
IVF is an infertility treatment in which the woman’s ovaries are stimulated to produce multiple oocytes (eggs), the oocytes are retrieved and fertilized, and embryo(s) are transferred back into the uterus. Traditionally, the oocytes are placed in a container with sperm to undergo fertilization. However, traditional IVF requires an adequate number of sperm which can move normally and potentially fertilize an egg. For men with low sperm count or quality, the alternate procedure ICSI can be used. ICSI directly injects a single sperm into each oocyte.
Not every oocyte can correctly undergo fertilization and form an embryo. Because of this, ICSI can increase the fertilization rate even when there is normal sperm quality. It is becoming more common to use ICSI rather than traditional IVF for couples with normal sperm quality, particularly when few oocytes are collected. This is more common with diminished ovarian reserve (DOR), a condition in which the ovaries produce few oocytes when stimulated.
It is not clear whether ICSI improves the pregnancy and birth rate compared to conventional IVF when there is normal sperm quality.
Methods & findings
This trial included 1064 couples with infertility and normal sperm count and motility (movement).
The couples had not had more than 2 previous cycles of IVF or ICSI. While taking ovarian stimulation medications, the women used GnRH antagonist to prepare the body. Half of the couples were assigned to use ICSI, and the other half used conventional IVF. 23% of women in the ICSI group and 27% of women in the IVF group had DOR.
Significantly more of the collected oocytes were successfully fertilized in the ICSI group (58.3% vs. 55.6%). However, there was no clear difference in fertilization failure (ICSI 5% vs. IVF 6%). Fertilization failure occurs when none of the collected oocytes fertilize correctly. However, couples using IVF were significantly more likely to not have an embryo available to transfer (4% vs. 2%).
The couples had one or two embryos transferred. After the first transfer, a similar number of couples in both groups had a positive pregnancy test. A similar number of couples in both groups gave birth to a child after the first embryo transfer (ICSI 35% vs. IVF 31%).
If pregnancy did not occur and there were embryos remaining, couples could do a second or third embryo transfer. 12 months after the IVF or ICSI cycle, there were a similar number of births or late pregnancies (ICSI 42% vs. IVF 41%).
The bottom line
This study found that ICSI did not increase live birth rates compared to conventional IVF for couples with normal sperm count. The authors suggest that the use of ICSI should be questioned in these couples due to more invasive procedures and increased costs.
The fine print
This trial did not look specifically at couples with few oocytes available. The trial also did not include couples for whom few oocytes were fertilized in previous cycles.
Published By :
Lancet (London, England)
Apr 24, 2021