Does sperm quality impact the success of in vitro fertilization for couples experiencing infertility?

This study examined if sperm quality affected the results of in vitro fertilization (IVF) in couples experiencing infertility. The results showed that higher sperm quality increased the chance of IVF success if few eggs were harvested.

IVF is a procedure where an egg is fertilized by a sperm in a dish. In cases where few sperm cells are recovered from the man, intracytoplasmic sperm injection (ICSI) can be used. This is where a sperm cell is directly injected directly into an egg. 

A lot of research surrounding the success of IVF has centered on the quality of eggs used. While this is very important, sperm are equally important for the development of a healthy embryo. It is unclear how sperm quality affects the success rate of IVF/ICSI.

Data from 765 couples who underwent ICSI were analyzed. Sperm numbers were used to assess sperm quality.

Low sperm numbers (less than 0.1 x 10⁶ cells) were associated with poorer IVF success than medium sperm numbers (1 × 10⁶ to 5 × 10⁶) or high sperm numbers (10 × 10⁶ to 39 × 10⁶). 29.6% of IVF rounds resulted in pregnancy in the low sperm group, compared to 40.7% in the medium sperm and 43.6% in the high sperm groups. 

22.2% of the low sperm group successfully had a birth following IVF. In comparison, 34.7% of the medium sperm group and 36.9% of the high sperm group had a birth following IVF. 25% of the low sperm group suffered a miscarriage. This was compared to 14.7% of the medium sperm and 15.4% of the high sperm group. 

Low sperm numbers affected couples most when few eggs (5 or less) were harvested for IVF. Couples who had few eggs and high sperm numbers had higher pregnancy and birth rates than couples with low sperm. Couples who had 6 or more eggs harvested were not affected by low sperm numbers.

The authors concluded that sperm quality affects the success of IVF/ICSI, especially for couples with low numbers of harvested eggs.

This study used medical records data, meaning that not all information was available. This study would benefit from looking at other aspects of sperm quality such as shape and movement of sperm cells.