While most of us are aware that smoking is a primary cause of diseases such as cancer, it’s important to also know about the impact it can have on your fertility. And as people start to switch cigarettes for vapes, research is being conducted to examine how these products can also affect your reproductive system.
If you smoke and are trying for a baby, or considering IVF treatment, you are putting yourself and baby at higher risk of issues such as miscarriage, stillbirth, low birth weight and ectopic pregnancy. It can also increase the risk of SIDS (Sudden Infant Death Syndrome) after your baby is born.
Medical professionals will advise you to try to quit smoking for 3-4 months before you try for a baby. The more you smoke, the bigger impact it will have on both a man and woman’s fertility and your ability to conceive and have a healthy baby. It is important to remember that secondhand smoke can also affect your ability to get pregnant.
Senior NHS consultant Professor Geeta Nargund says: “Doctors will always recommend women stop smoking if they are trying for a pregnancy in order to reduce potential risks and complications, and if women feel they need support with quitting, their GP will be able to offer them help and advice.” If you are hoping to access any NHS-funded, or private, fertility treatment such as IVF or IUI you will also be advised to be smoke-free.
While the number of people who smoke cigarettes in the UK is declining, it’s estimated that around 1 in 8 of us smokes. According to the charity ASH (Action on Smoking and Health), in 2022 13.8% of 25-34 year olds and 11.8% of 35-49 year olds smoked in the UK. These were the two age cohorts with the highest percentage of smokers.
How smoking impacts female fertility
Smoking has a huge impact on female fertility and this study found that it actually affects every system involved in the reproductive process. It summarised that “couples in reproductive age should be strongly discouraged to smoke”.
- 1. Impacts ovarian function - All of the experts we spoke to agreed that there is no safe level of smoking and your ability to conceive will be affected. Professor Scott Nelson, medical director at Access Fertility, says smoking reduces the number and quality of a woman’s eggs: “This reduction means that you are less likely to conceive naturally and even in IVF the success rates are reduced by about 50%.”
Smoking can also affect the uterus’s ability to allow embryos to implant because the tobacco can affect uterine receptivity. This study states that cotinine, a by-product of nicotine, can also damage your fallopian tubes which can increase your risk of ectopic pregnancy, which is when the foetus begins to develop outside of the uterus. - 2. Quality of eggs - You are also putting your eggs at risk by smoking. Gynaecologist and women’s health specialist Dr Georgina Leslie explains: “Women who smoke have a lower ‘ovarian reserve’ meaning that they have fewer eggs remaining than those that have never smoked. Regular smoking can deplete the quality of egg cells, by causing premature ageing and damage. In animals smoking has been shown to damage the growing follicle (which contains the egg) and reduce its growth, affecting ovulation.”
- 3. Hormonal imbalance - Dr Leslie from the London Hormone Clinic, says studies have shown that smokers have shorter and more variable menstrual cycle lengths than non-smokers, which can lead to fertility issues. If the timing of ovulation is less predictable it can be hard for couples to know when best to have sex in order to conceive. This study says smoking is associated with lower oestrogen levels and higher follicle stimulating hormone (FSH) levels which can increase menstrual bleeding and shorten cycles. Professor Nelson says this can “lead to anovulation (absence of ovulation) or irregular ovulation”.
- 4. Earlier menopause - As we’ve explained above, smoking can have a negative impact on your menstrual cycle and this also means that smokers have shorter menstrual cycle lifespans. This means they’re more likely to start menoapause earlier than non-smokers. Professor Nelson explains: “Women who smoke are more likely to experience menopause 1-4 years earlier than non-smokers. The toxins in cigarette smoke accelerate the depletion of ovarian follicles, leading to a shorter reproductive lifespan.” Dr Leslie says the symptoms of menopause such hot flashes and insomnia can also be worse if you’re a smoker.
Increased risks
- 1. Miscarriage - As we’ve mentioned above, smoking while trying to conceive, and continuing when you are pregnant, can greatly increase your risk of complications. A 2010 report by the Royal College of Physicians states that smoking during pregnancy increases the risk of miscarriage by 24-32%. It said each year in the UK, an estimated 3,000 to 5,000 miscarriages are caused by maternal smoking. Dr Leslie says this is because “while a damaged egg may be successfully fertilised and implanted in the bed of the uterus, it may not sustain the uterine environment for very long. Continued smoking can affect the embryo quality and development of the fetus, and in turn, increase the risk of miscarriage”.
Secondhand smoke exposure during pregnancy can also increase the risk of miscarriage by 11%, according to this study in the American Journal of Epidemiology. - 2. Premature birth and low birth weight - Smoking also puts your baby at risk of premature birth and again, the more you smoke, the higher the risk. A British Medical Association (BMA) review of 20 studies, based on 65,910 pregnancies, of which 6,183 were premature, showed that maternal smoking increased the risk of having a premature birth by 27%. Smoking fewer cigarettes will not reduce the risk of premature birth or low birth weight. You need to stop completely.
- 3. Stillbirth - A review published in 2015 found that women who smoke during pregnancy have a 47% increased risk of stillbirth and that the risk of death increases with the amount smoked during pregnancy. Professor Nelson states: “Smoking during pregnancy is perceived globally as the most common preventable cause of infant morbidity and mortality.”
How vaping impacts female fertility
Vaping is sometimes seen as a ‘safe’ alternative to smoking cigarettes but research on the impact of using these products is still limited. The ingredients and chemicals in each e-cigarette vary according to the manufacturer and many will still contain toxins which can affect our reproductive health. Vaping is becoming more and more popular so it’s important that couples trying for a baby understand the implications it can have on their fertility.
Our experts agreed that more research is needed on the impact of vaping on fertility but Professor Nelson says: “E-cigarettes contain nicotine and other harmful chemicals that can potentially disrupt hormonal balance and damage reproductive cells, similar to traditional cigarettes.”
Vapes still contain nicotine which is a chemical which can disrupt the hypthalamic-pituitary-gonadal axis in smokers. Sexual hormones created by these glands such as FSH, luteinizing hormone, sex hormone-binding globulin (SHBG) and cortisol can all have their levels altered by nicotine which this 2023 study says can make it harder to become pregnant.
One study by women’s health firm Hertility, which examined blood samples of 8,340 women who used vapes and women who didn’t, also found that those who smoked had lower levels of anti-Müllerian hormone (AMH), which can be assessed to show how many eggs women have left in their ovaries.
Medical director of abc IVF, professor Nargund, says: “Although extensive, long-term research is needed to better understand the impact of vaping on fertility in both men and women, as a fertility doctor I would recommend quitting to improve chances of conceiving and reducing risk of complications during pregnancy.”
Secondhand smoke and fertility
We have outlined the risks associated with being exposed to secondhand smoke on fertility and pregnancy above. If you live with someone who smokes you will also be breathing in the toxins (tobacco and carbon monoxide) which will be entering your bloodstream. The vapour from an e-cigarette may also contain harmful chemicals which can affect your fertility and unborn baby. Opening windows and doors in a house or car won’t decrease your smoke inhalation as it can linger in the air for hours. Stop smoking counsellors and your GP will always recommend that both partners try to quit smoking when trying for a baby, or as soon as possible after becoming pregnant.
If a male partner continues to smoke while trying to conceive the impact on his sperm count and quality could cause complications in the pregnancy. As we’ve explained, damage to the sperms’ DNA can lead to miscarriage and poorer quality embryos. The baby loss charity Tommy’s is carrying out important research into this issue.
Can you reverse the impact of smoking on fertility?
There is good news when it comes to reversing the health impact of smoking. Professor Nelson says studies have shown that the negative impact on your eggs and sperm can begin to reverse within three months. “However, the timeline for recovery can depend on the duration and intensity of smoking habits, as the reduction in egg count is irreversible,” he adds. “It is essential for both men and women to quit smoking well before attempting to conceive to maximise their chances of a healthy pregnancy and baby.”
Dr Hasan says you can also turn things around if you quit vaping. “With the regeneration of sperm being an average of 74 days, ceasing the use of vaping can lead to the production of healthier sperm. This improvement in sperm quality can significantly enhance overall fertility prospects. This good news can often be missed within the negativity surrounding the topic online and is a much more uplifting and encouraging message to consumers who vape.”
FAQs about smoking and fertility
Will IVF be successful if I smoke?
The London Women’s Clinic says if you smoke when you start IVF treatment it could lead to fewer eggs being retrieved and fewer embryos. “For women who smoke during treatment, there is around a 50% less chance of implantation occurring following IVF than those who did not smoke,” the website says.
If you become pregnant via IVF and smoke then the same risks as outlined above will apply such as miscarriage, low birth weight and stillbirth.
