Any couple who has been struggling to get pregnant for a while will be familiar with the various fertility tests that are usually offered. For her it’s a blood test to check for ovulation, a hysterosalpinogram to check to see whether the fallopian tubes are clear and sometimes an AMH test to check her ovarian reserve. For him it’s usually just a semen analysis.
The standard semen analysis has been around ever since IVF was invented and it hasn’t been improved on since. There are quite a few things measured in the semen analysis but the main ones that couples will be familiar with are sperm count (the total number of sperm), motility (their swimming ability) and morphology (the shape and size of the sperm).
A semen analysis is a pretty crude test – it just looks at the outside of the sperm and tells you little about the intrinsic quality of the sperm DNA or its healthy baby-making abilities. Certainly if a man’s sperm count is very low, or they’re not good swimmers, or if most of them have some abnormality (like two tails!) then, yes, that man’s fertility is going to be compromised.
Sperm DNA fragmentation might be the missing link and testing for it adds new information to help explain these situations. Sometimes the DNA becomes damaged or fragmented – with strands breaking into smaller pieces. Even healthy sperm may have some degree of DNA damage, as they can’t repair themselves. Sometimes, if there is too much sperm DNA damage, that can prevent fertilization taking place at all.
Amazingly, sometimes the egg is actually able to repair some of the sperm’s DNA damage and fertilization can take place. But when there is too much sperm DNA damage for the egg to repair, that can lead to the pregnancy stalling almost immediately, or you do get pregnant, but some time further down the line, suffer a miscarriage.
Professor Sheena Lewis is the UK’s leading expert in sperm DNA fragmentation, and for 25 years she and her team have been working on new tests for the diagnosis of male infertility. The test is so sensitive that it detects damage in 80% of men with ‘unexplained infertility’, who seem to have normal semen by traditional tests.
Sperm DNA damage is often a factor when couples have been trying for a baby for some time without success. If we find there is a lot of sperm DNA damage, we can help couples make better choices about the right lifestyle choices and the best fertility treatment for them. For example, with moderate damage, IVF might be the best treatment to try first. If the damage is higher, then the best chance of success might be going straight to ICSI treatment.
Men are lucky. Unlike women who have all their eggs at birth, men make a new batch of sperm every 3 months. If they test high for sperm DNA damage, they can take control by improving their lifestyle and DNA damage levels can decrease within within 3 -4 months.