Use of ICSI on rise, but are outcomes better?
Results of a retrospective cohort study1 by investigators from the Centers for Disease Control and Prevention (CDC) and Emory University show that use of intracytoplasmic sperm injection (ICSI) is on the rise but cast doubt on whether the technology is improving reproductive outcomes.
The findings, which were most striking in cases without male-factor infertility, reflect national trends with fresh cycles of in vitro fertilization (IVF) and have sparked significant discussion in the ob/gyn community.
Nearly 1.4 million fresh IVF cycles from 1996 through 2012 were represented in the study, based on data on fresh IVF and ICSI cycles reported to the US National Assisted Reproductive Technology Surveillance System (NASS) from 1996 to 2012. Using linear regression, the authors looked at trends in ICSI use during that period for ICSI in all fresh cycles and those with male factor infertility, unexplained infertility, maternal age 38 years of older, low oocyte yield, and two or more prior assisted reproductive technology (ART) cycles.
Reproductive outcomes for conventional IVF and ICSI from 2008 to 2012 were assessed and the data were stratified by the presence or absence of male-factor infertility.
From 1996 through 2012, ICSI was used in 65.1% of the 1,395,634 fresh IVF cycles and male-factor infertility was reported in 35.8% (499,135) cycles. Among cycles with male-factor infertility, ICSI use increased from 76.3% to 93.3% (P<.001), compared with an increase from 15.4% to 66.9% (P<.001) during that time period. Among the 35.7% of fresh cycles from 2008 to 2012 for which male-factor infertility was reported, the rate of multiple birth was lower than with conventional IVF (30.9% vs 34.2%; adjusted relative risk [RR], 0.87; 95% CI, 0.83-0.91). Among cycles without male-factor infertility, ICSI use was associated with lower rates of implantation (23.0% vs 25.2%; adjusted RR, 0.93; 95% CI, 0.91-0.95), live birth (36.5% vs 39.2%; adjusted RR, 0.95; 95% CI, 0.93-0.97), and multiple live birth (30.1% vs 31.0%; adjusted RR, 0.93; 95% CI, 0.95-0.95) versus conventional IVF.
The authors concluded that compared with conventional IVF, ICSI use was not associated with improved post- fertilization reproductive outcomes, irrespective of male-factor infertility diagnosis. They acknowledged that the study was limited, in that NASS does not collect information on fertilization rates, nor on outcomes for ICSI versus IVF for cryopreserved oocytes.
1. Boulet SL, Mehta A, Kissin DM, Warner L, Kawwass JF, Jamieson DJ. Trends in use of and reproductive outcomes associated with intracytoplasmic sperm injection. JAMA. 2015;313(3):255–263.