ICSI May Not Be Best for Unexplained Infertility

February 11, 2015

Use of intracytoplasmic sperm injection in cases unrelated to male factor infertility may negatively affect outcomes, new research suggests.

While intracytoplasmic sperm injection (ICSI) use has doubled in the past decade, the procedure is not leading to more successful fertilizations, irrespective of male factor infertility, according to a new study from the CDC.

In fact, the method was no more effective than conventional in vitro fertilization (IVF), the authors reported.

Key Finding:

- Intracytoplasmic sperm injection, while increasingly popular, does not appear to be associated with better outcomes when compared with conventional IVF treatment.

According to the researchers, including Sheree L. Boulet, DrPH, MPH, of the Division of Reproductive Health at the CDC, ICSI is much more expensive than traditional IVF, and it also poses a higher risk of transmitted genetic abnormalities. The finding suggests a need for scientific evidence to back the continued use of ICSI.

The researchers found that when addressing male infertility, reproductive outcomes of fresh IVF cycles using ICSI were similar to outcomes of cycles using conventional IVF. And when ICSI was used when male infertility wasn’t the reason for treatment, the researchers identified "small but significant" reductions in implantation, pregnancy, live birth, and multiple live birth, compared with cycles using conventional IVF unrelated to male infertility.

Using data on fresh IVF and ICSI cycles reported to the U.S. National Assisted Reproductive Technology Surveillance System during 1996 to 2012, the researchers identified 1,395,634 fresh IVF cycles. Of those, 65.1% used ICSI and 35.8% reported male factor infertility.

When IVF was performed because of male infertility, ICSI use increased from 76.3% to 93.3%; for those without male factor infertility, ICSI use increased from 15.4% to 66.9%.

"Although such differences may be a function of the large sample size and thus not clinically relevant, our findings suggest that use of ICSI may improve fertilization rates but not implantation or pregnancy rates in the setting of unexplained infertility, advanced maternal age, and low oocyte [a cell from which an egg develops] yield," the authors wrote.

The study was published in the Journal of the American Medical Association.