Smoking significantly impacts both female and male fertility, often doubling the risk of infertility compared to non-smokers. Because tobacco contains over 7,000 chemicals, including toxins like nicotine, cyanide, and carbon monoxide, it can disrupt nearly every stage of the reproductive process. 

Effects on Female Fertility

Accelerated Ovarian Aging: Chemicals in smoke speed up the loss of eggs, which cannot be replaced. This typically leads to smokers reaching menopause 1 to 4 years earlier than non-smokers.

Damaged Egg Quality: Smoking can cause genetic abnormalities in eggs, increasing the risk of miscarriage and birth defects.

Hormonal and Cycle Issues: It can disrupt estrogen and progesterone production, leading to irregular periods and ovulation problems.

Increased Risk of Ectopic Pregnancy: Smoking impairs the movement of the fallopian tubes, making it more likely for a fertilized egg to implant outside the womb.

Impaired IVF Success: Female smokers often require higher doses of stimulating medications and have lower pregnancy rates during IVF. 

Effects on Male Fertility

Reduced Sperm Quality: Smokers often have lower sperm counts (up to 20% lower), reduced motility (movement), and more abnormally shaped sperm.

DNA Damage: Toxins can cause DNA fragmentation in sperm, which may lead to fertilization failure or miscarriage even if a partner conceives.

Erectile Dysfunction: Nicotine constricts blood vessels and reduces penile blood flow, increasing the risk of impotence.

Hormonal Imbalance: Smoking can lower testosterone levels and disrupt the hormones needed for sperm production. 

Secondhand Smoke & Vaping

Passive Smoking: Being around smoke is nearly as damaging as active smoking, often increasing the time it takes to conceive and raising miscarriage risks.

Vaping/E-cigarettes: While research is ongoing, many e-cigarettes still contain nicotine and heavy metals that can harm reproductive health and fetal development. 

Reversing the Effects

The good news is that many of these effects are reversible. Stopping smoking can improve sperm quality within 2 to 3 months (the time it takes for new sperm to mature) and can improve natural fertility levels in women within a year.