Trying to conceive? Doctors warn smoking may be affecting fertility in men and women

Trying to start a family is imagined as a joyful phase. But for many couples, it becomes stressful, emotional, and confusing when pregnancy takes longer than expected. Conversations usually revolve around age, stress, diet, hormones, or medical conditions. One factor, however, often stays hidden in plain sight: smoking.

Many people still associate smoking only with lung disease or heart problems. What goes unnoticed is how deeply tobacco affects reproductive health in both men and women. Cigarettes, vaping devices, and even second-hand smoke can quietly interfere with fertility long before visible health problems appear.

According to the US Centers for Disease Control and Prevention (CDC), smoking can reduce fertility, damage sperm health, increase the risk of miscarriage, and lead to complications during pregnancy.

Why smoking affects fertility earlier than most people think

One of the biggest misconceptions around fertility is that if someone appears healthy, fertility must also be normal. Fertility specialists say this is often not true.

Dr Sahana K P, Consultant Obstetrician and Gynaecologist, Apollo Hospitals, Sheshadripuram, Bangalore, explains that smoking affects the very cells needed for reproduction.

“Smoking hurts the cells that are needed to get pregnant. In men smoking can affect the quality of their sperm, how well their sperm move and how many sperm they have. In women smoking can hurt the quality of their eggs, mess with their hormones and even cause their ovaries to stop working earlier,” she says.

Tobacco smoke contains thousands of chemicals. Many of them directly damage reproductive tissues. Studies have shown that smoking may reduce sperm count, damage sperm DNA, affect hormone production, and lower the chances of conception.

For women, the impact can be equally serious. Smoking has been linked to ovulation problems, reduced blood flow to reproductive organs, ectopic pregnancy, miscarriage, and earlier menopause.

Doctors say the difficult part is that these changes often happen silently. Many couples only discover the issue after months or years of trying to conceive.

Male fertility is part of the conversation too

Fertility discussions still tend to focus heavily on women, but specialists say male fertility contributes to nearly half of infertility cases globally.

Smoking in men has been associated with:

1. Lower sperm count
2. Reduced sperm motility
3. Abnormal sperm shape
4. DNA damage in sperm
5. Erectile dysfunction
6. Lower testosterone levels

Dr Sahana points out that many men are shocked when lifestyle habits become part of fertility evaluations.

“Many people think fertility problems are only a woman’s issue. Actually men are responsible for about half of all fertility problems,” she says.

Even passive smoking matters. Women exposed to second-hand smoke at home or work may also face fertility challenges. According to the CDC, second-hand smoke exposure during pregnancy has been linked to lower birth weight and preterm delivery.

Smoking and birth control: A combination doctors worry about

While smoking affects fertility, it can also become dangerous for women using hormonal birth control pills.

Dr Preeti Prabhakar Shetty, MBBS, MD - Obstetrics & Gynaecology, Senior Consultant Obstetrician and Gynecologist, Apollo Hospitals, Bannerghatta Road, Bangalore, says many women underestimate this risk.

“For many women, taking birth control pills is a routine part of life. But when smoking is added to the picture, it quietly changes the risk profile in ways that are often underestimated,” she explains.

Most birth control pills contain estrogen. Estrogen can increase the tendency of blood to clot. Smoking damages blood vessels and also increases clot formation. Together, the combination raises the risk of serious complications involving the heart, lungs, and brain.

Doctors are especially concerned about:

1. Deep vein thrombosis (blood clots in the legs)
2. Pulmonary embolism (blood clots reaching the lungs)
3. Stroke
4. Heart attack

The risks become significantly higher in women above 35 who smoke regularly.

Dr Preeti explains that the concern is not that smoking makes birth control ineffective.

“The real issue is not failure of contraception, but the increased risk to overall health,” she says.

She adds that safer alternatives do exist for women who smoke, including progestin-only pills, hormonal implants, injections, and intrauterine devices (IUDs), especially non-estrogen methods.

Doctors also advise women to immediately seek medical attention if they experience warning signs such as sudden chest pain, breathlessness, severe headaches, blurred vision, or swelling in the legs.

Why quitting smoking is harder than it sounds

Many smokers already know cigarettes are harmful. Yet quitting remains incredibly difficult because nicotine affects both the body and the brain.

Dr Vishwanath Sathyanarayanan, Senior Consultant Medical Oncologist and Academic Advisor, Apollo Hospitals Bangalore, says nicotine addiction creates physical and mental dependence, which is why withdrawal symptoms become difficult to manage.

But there is growing evidence that physical activity may help reduce cravings and support recovery.

“Some forms of physical activity can improve the chances of quitting by lowering stress levels, mood stabilization and by channelizing the mind to think beyond smoking,” he says.

Exercise also improves circulation, lung function, heart health, and emotional wellbeing. Doctors say movement gives the body a healthier source of dopamine and endorphins, which smokers often seek through nicotine.

Five simple workouts that may help smokers quit

1. Brisk Walking: A 30-minute brisk walk may help reduce nicotine cravings and improve circulation. Doctors say walking also helps reverse some of the inflammation caused by smoking. A practical target for many adults is around 10,000 steps daily.
2. Breathing Exercises And Yoga: Smoking weakens lung capacity over time. Practices like pranayama and yoga may improve breathing control, reduce stress, and help people manage cravings more calmly.
3. Cycling And Swimming: Cycling can improve mood and stamina, while swimming supports lung function and overall cardiovascular health. Even doing these once or twice a week may help people feel physically stronger during the quitting phase.
4. Strength Training: Simple resistance exercises at home can help reduce stress hormones and improve confidence. Doctors say consistency matters more than intensity.
5. Dancing Or Aerobic Workouts: Activities like Zumba or dance workouts make movement enjoyable. They improve mood naturally and may reduce withdrawal symptoms after quitting smoking.

Dr Vishwanath says support systems matter deeply during this phase.

“Quitting smoking is a process which involves a great support system from the family and health care professionals,” he says.

Small changes can make a big difference

Fertility treatments can be emotionally exhausting and financially demanding. Doctors say quitting smoking remains one of the most effective lifestyle decisions couples can make before planning pregnancy.

The encouraging part is that the body does begin to recover after quitting. Sperm quality may improve within months, hormone balance can gradually stabilise, and pregnancy outcomes may become healthier over time.

The earlier the change happens, the better the chances of protecting long-term reproductive health.

Medical experts consulted
This article includes expert inputs shared with TOI Health by:

Dr Sahana K P, Consultant Obstetrician and Gynaecologist, Apollo Hospitals, Sheshadripuram, Bangalore.
Dr Vishwanath Sathyanarayanan, Senior Consultant Medical Oncologist & Academic Advisor, Apollo Hospitals Bangalore.
Dr Preeti Prabhakar Shetty, MBBS, MD - Obstetrics & Gynaecology, Senior Consultant Obstetrician,Gynecologist, Apollo Hospitals, Bannerghatta Road, Bangalore.

Inputs were used to explain how smoking quietly impacts male and female fertility, affects pregnancy outcomes, and increases health risks linked to birth control, while experts highlighted why quitting early and seeking medical guidance can significantly improve reproductive health.