In a widely shared video from February 15, 2026, UK-based surgeon and health expert Dr. Karan Rajan shifted the pregnancy spotlight onto fathers. He argues that the traditional focus on maternal health alone misses “half the picture,” as paternal lifestyle choices in the three months leading up to conception are critical co-founding factors for a child’s development.
The “74-Day Sperm Cycle”
Dr. Rajan explains that sperm development (spermatogenesis) takes roughly 74 days. During this window, any harmful habits can directly alter the genetic and epigenetic “tags” carried by the sperm.
- DNA Fragmentation: Smoking, excessive alcohol, and chronic stress can cause the sperm’s DNA to break or “fragment.”
- Epigenetic Alterations: These are chemical modifications that don’t change the DNA code itself but change how genes are “switched on or off.”
Paternal Risks: Developmental Issues
While maternal health is linked to the first eight weeks of organ formation via the placenta, “damaged” sperm can contribute to a variety of issues for the future child, including:
- Heart Defects: Paternal smoking and oxidative stress are linked to higher rates of congenital heart malformations.
- Craniofacial Problems: Epigenetic changes can disrupt the delicate formation of the baby’s face and skull.
- Metabolic Disorders: A father’s poor diet or obesity before conception can “program” the child for a higher risk of obesity, diabetes, and cardiovascular disease later in life.
- Pregnancy Complications: Dr. Rajan notes that since the placenta is primarily driven by paternal genes, poor sperm quality is linked to a higher risk of gestational diabetes and preeclampsia in the mother.
The Surgeon’s “Male Preconception Playbook”
To minimize these risks, Dr. Rajan suggests men treat the three months before trying to conceive as a training period:
| Recommendation | Why It Matters |
| Quit Smoking/Alcohol | Reduces DNA fragmentation and prevents changes to sperm morphology (shape). |
| Folate & Zinc | Folate isn’t just for moms; in men, it prevents chromosomal abnormalities in sperm. |
| Vitamin D | Crucial for both healthy sperm development and later placental health. |
| Fix Your Sleep | Poor sleep is directly linked to lower total sperm count and reduced motility. |
| De-stress | Chronic stress releases cortisol, which can mess with the “epigenetic signatures” of sperm. |
The Bottom Line: While developmental issues can sometimes occur by pure chance or environmental factors, optimizing health for both parents is the best way to lower the odds of complications.