When going through IVF or ICSI, most people expect the focus to be on the woman’s eggs. But sperm health is just as important – and not just for fertilisation.
The First Few Days
After sperm meets egg, the first 2–3 days of embryo growth are powered by the mother’s egg. The egg is packed with proteins and instructions that keep the embryo dividing.
Around day three, something big changes. The embryo must switch on its own DNA – half of which comes from the father. This step is called zygotic genome activation. If the DNA from the sperm is badly damaged, the embryo may stop growing or fail to implant.
Can the Egg Fix Damaged DNA?
Eggs are clever. They can repair some DNA problems from sperm, especially when damage is mild. But this repair system isn’t unlimited. If there’s too much damage, or if the woman is older (and the egg’s repair ability has declined), the embryo may not make it past these early stages.
What Damages Sperm DNA?
One of the biggest culprits is oxidative stress. This happens when there’s an imbalance between free radicals (unstable molecules that damage cells) and antioxidants (the body’s natural defence system). Lifestyle factors such as smoking, alcohol, poor diet, stress, and environmental toxins can all raise oxidative stress, leading to sperm DNA breaks.
What Can Help?
Research shows that improving sperm quality can boost embryo development and pregnancy success rates. Some things that may help include:
- Supplements – Antioxidants like vitamin C, vitamin E, zinc, selenium, and CoQ10 may protect sperm DNA from oxidative stress.
- Lifestyle changes – Improving diet, exercising moderately, getting good sleep, and avoiding toxins all make a difference.
- Chinese herbs – In Traditional Chinese Medicine, herbs are prescribed to restore balance, improve circulation, and support sperm health. Some herbs have antioxidant properties, meaning they may help protect sperm from oxidative stress and DNA damage.
The Takeaway
Sperm quality matters well beyond fertilisation. Healthy sperm DNA gives embryos the best chance of growing, implanting, and developing into a healthy pregnancy. Taking care of both egg and sperm health – with the right lifestyle, supplements, and supportive treatments – can make all the difference on the fertility journey.
References
- Lourenço ML et al. Impact of sperm DNA fragmentation on ART outcomes (review/meta-analysis).
- Niakan KK et al. Human pre-implantation embryo development (maternal program and zygotic genome activation).
- Lee MT et al. Zygotic genome activation during the maternal-to-zygotic transition.
- Leem J et al. Capacity to repair sperm DNA damage in zygotes (Frontiers, 2022).
- Li N et al. Mechanisms for repairing sperm DNA after fertilisation (2024 review).