New Approach May Predict IUI Success
SAN FRANCISCO—Multiplying total motile sperm count by the percent of normal sperm determined by strict morphology (TM×SM) may be a significant predictor of pregnancy when sperm morphology is less than 5%, according to a new study by Texas researchers.
Appropriate counseling for teratozoospermia is controversial. It has been suggested that in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) may be the best treatment option for couples with less than 5% normal sperm strict morphology. Wanting to investigate whether the 5% threshold or the TM×SM was a significant predictor of intrauterine insemination (IUI) success, researchers looked at infertile couples undergoing IUI at their institution between November 1995 and December 2007. Their findings suggest that TM×SM may be helpful in selecting couples who are not suitable for IUI.
Exclusion criteria were female age greater than 40 years, history of endometriosis, tubal factor, or history of previous IVF or use of donor sperm. A total of 237 couples were included in the study. The investigators determined total motile sperm counts for each of the initial semen analyses and used the Kruger strict morphology criteria to calculate the percentage of total normal sperm, then multiplied to get the TM×SM.
The overall cumulative pregnancy rate was about 30%. Mean female age, mean strict morphology, mean TMC, and mean TM×SM in both the pregnant and nonpregnant groups were similar. The pregnancy rate was 24% in couples with strict morphology less than 5% (about 45% of the cohort) compared with a pregnancy rate of 34% in couples with strict morphology of 5% or more. The difference was not statistically significant.
In couples with SM less than 5%, the pregnant group had a significantly higher mean TM×SM compared with the nonpregnant group (3.7 million vs. 2.3 million). No pregnancies occurred in the 14 couples whose TM×SM was less than 0.29 million. Overall, TM×SM was the only significant predictor of pregnancy in couples with SM below 5%.
“The take-home message is not to look at strict morphology alone. You should also look at the total motile count and combine it with the strict morphology,” said study investigator Ertug Kovanci, MD, assistant professor of obstetrics and gynecology at Baylor College of Medicine in Houston. “Sometimes IVF with ICSI is recommended just because the strict morphology is less than 5%. But we are saying that if the total motile count is good, you don't have to do IVF with ICSI [in these couples]. You can get away with IUIs.”
That could lead to huge costs savings because IUI is both less invasive and less expensive, he said. Dr. Kovanci noted that this retrospective study in a relatively small number of couples does have limitations, so these findings need to be replicated in a larger cohort.
Findings were presented here at the American Society for Reproductive Medicine annual meeting.