The World Anti-Smoking Day is celebrated every year on May 31. Throughout the month of June, non-governmental agencies and other stakeholders in the health sector focus on the hazards of smoking worldwide.
The Centre for Disease Control and Prevention in the United States of America states that cigarette smoking is the leading preventable cause of death in that country. Smoking, according to the centre, accounts for more than 480,000 deaths in the country each year. More American citizens have died prematurely from cigarette smoking than were killed in all the wars fought by their country. Smoking causes about 90 per cent (or nine out of 10) of all lung cancer deaths. More women die from lung cancer each year than from breast cancer.
Smoking causes about 80 per cent (or eight out of 10) of all deaths from chronic obstructive pulmonary disease. Also, it increases the risk of death from all causes in men and women. The risk of dying from cigarette smoking has grown over the last 50 years in the U.S.A.
In this write up, my focus will be on the damages caused by smoking to fertility and reproduction. It affects active and passive smokers. Several studies have linked cigarette smoking with infertility, emphasising a causal association that exists between them.
About 30 per cent of reproductive age women and 35 per cent of reproductive age men in the U.S smoke cigarettes, as do many adolescents and teenage girls, despite costly and long-standing campaigns to limit their use.
According to the World Health Organisation, infertility in women is the fifth highest global severe disability, especially among populations under the age of 60.
The causes of infertility, which is a global health issue, include male factors, female factors, combined factors and idiopathic (unknown) causes. It is a multidimensional problem with socio-economic, cultural and spiritual implications and a cause of marital disharmony and distress to couples.
Childbearing is a significant event amongst couples, especially those of African descent, who strongly associated it with the ultimate goals of fulfillment, happiness and family completeness. In the United Kingdom, infertility affects about one in every six or seven couples.
Infertility is defined as the inability of a couple to achieve spontaneous conception after trying for at least six months or one year for women over 35 years without using any form of contraception, despite adequate (two to three times on alternate days, at least) sexual intercourse. Apart from advanced maternal age, sexually transmitted diseases, congenital/genetic causes, endocrine causes, chemotherapy, exposure to radiation and other known causes of infertility, lifestyle patterns and environmental pollutants, such as cigarette smoking, play a crucial causative role in infertility.
A study published by the CDCP shows that while smoking rates among women in the western world have fallen recently, the habit remains a significant cause of newborn deaths, preterm births and Babies with Low Birth Weight.
A systematic review of the scientific literature on the impact of cigarette smoking and smoke constituents revealed that all stages of reproductive functions are targets of cigarette smoke toxicants. In the UK alone, smoking in pregnancy is responsible for about 5,000 miscarriages, 3,000 perinatal deaths and approximately 2,000 premature births each year. Although the data for Nigeria is not available, because we have a depleted infrastructure and limited health services, these values may be much higher than reported above.
According to the WHO, smoking causes more death in one year than all of these combined: deaths due to HIV, illegal drug use, alcohol use, motor vehicle injuries and fire-related incidents.
It has been proven that women who smoke take longer to conceive than women who do not smoke. Some studies found out that tobacco use affects the receptivity of the uterus, a higher incidence of ectopic pregnancies, particularly among heavy smokers. Comparatively, low-level smoking, ‘side-stream’ and passive smoking (inhaling smoke from other people smoking) can have detrimental effects on fertility.
There is recent evidence, which suggests that smoking affects the success rate of fertility treatment. Research has depicted that women undergoing Assisted Reproductive Treatment (www.medicalartcenter.com) have a significant adverse outcome compared to non – smokers. A study even showed a 50 per cent decline in implantation rate in smokers.
The impact of tobacco compounds in the process of ovarian follicle maturation is expressed by worse IVF parameters in cycles performed, and smoking habit significantly alters uterine receptiveness and tubal function.
Smoking causes a reduction in the number of germ cells (sperm and egg forming cells) and somatic cells (cells that form the body parts) in the uterus. It can also affect protamine, a protein essential for sperm production. Males born to women who smoked during pregnancy are at risk of having small testes, low sperm counts, concentration and high abnormalities.
Lifestyle and social behavior have over the years been proven to have deleterious effects on fertility and implicated in early pregnancy losses, preterm births, and low birth weight babies. In men, effects of smoking are evidenced by a reduction in sperm production, increase in oxidative stress and DNA damage. Sperms from smokers have to decrease fertilising capacity and embryos have reduced implantation capabilities, hence the reduction of implantation rates.