Tobacco smoking during pregnancy causes many detrimental effects on health and reproduction, in addition to the general health effects of tobacco. A number of studies have shown that tobacco use is a significant factor in miscarriages among pregnant smokers, and that it contributes to a number of other threats to the health of the foetus. [1] [2] [3]
Because of the associated risks, people are advised not to smoke before, during or after pregnancy. If this is not possible, however, reducing the daily number of cigarettes smoked can minimize the risks for both the mother and child. This is especially true for people in developing countries, where breastfeeding is essential for the child's overall nutritional status. [4]
Women who are pregnant or planning to become pregnant are advised to stop smoking. [5] [6] It is important to examine these effects because smoking before, during and after pregnancy is not an unusual behavior among the general population and can have detrimental health impacts, especially among both mother and child, as a result. In 2011, approximately 10% of pregnant women in data collected from 24 U.S. states reported smoking during the last three months of their pregnancy. [7]
According to a 1999 meta-analysis published in the American Journal of Preventive Medicine , smoking prior to pregnancy is strongly related to an increased risk of developing an ectopic pregnancy. [6]
According to a study conducted in 2008 by the Pregnancy Risk Assessment Monitoring System (PRAMS) that interviewed people in 26 states in the United States, approximately 13% of women reported smoking during the last three months of pregnancy. Of women who smoked during the last three months of pregnancy, 52% reported smoking five or fewer cigarettes per day, 27% reported smoking six to 10 cigarettes per day, and 21% reported smoking 11 or more cigarettes per day. [8]
In the United States, women whose pregnancies were unintended are 30% more likely to smoke during pregnancy than those whose pregnancies were intended. [9]
Smoking during pregnancy can lead to a plethora of health risks and damage to both the mother and the fetus.
Women who smoke during pregnancy are about twice as likely to experience the following pregnancy complications: [10]
According to a 1999 meta-analysis published in the American Journal of Preventive Medicine , smoking during pregnancy is related to a reduced risk of developing pre-eclampsia. [6]
Some studies show that the probability of premature birth is roughly 50% higher for women who smoke during pregnancy, going from around 8% to 11%. [12]
Smoking can also impair the general development of the placenta, which is problematic because it reduces blood flow to the fetus. When the placenta does not develop fully, the umbilical cord which transfers oxygen and nutrients from the mother's blood to the placenta, cannot transfer enough oxygen and nutrients to the fetus, which will not be able to fully grow and develop. These conditions can result in heavy bleeding during delivery that can endanger mother and baby, although cesarean delivery can prevent most deaths. [13]
There is limited evidence that smoking reduces the incidence of pregnancy-induced hypertension, [14] but not when the pregnancy is with multiple babies (i.e. it has no effect on twins, triplets, etc.). [15]
Other effects of maternal smoking during pregnancy include an increased risk for Tourette syndrome and tic disorders. There is a link between chronic tic disorders, which include Tourette syndrome and other disorders like ADHD and OCD. According to a study published in 2016 in the Journal of the American Academy of Child and Adolescent Psychiatry, there is an especially high risk for children to be born with a chronic tic disorder if their mother is a heavy smoker. Heavy smoking can be defined as ten or more cigarettes each day. With this heavy smoking, researchers have found that there is an increase in risk as high as 66% for the child to have a chronic tic disorder. Maternal smoking during pregnancy is also associated with psychiatric disorders such as ADHD. Concerning the increase risk for Tourette syndrome, there is an increased risk when two or more psychiatric disorders are also existent as maternal smoking leads to a higher chance of having a psychiatric disorder. [16]
Pregnant women who smoke may be at risk of having a child with cleft palate. [17]
Smoking during pregnancy can result in lower birth weight as well as deformities in the fetus. [18] [19] Smoking nearly doubles the risk of low birthweight babies. In 2004, 11.9% of babies born to smokers had low birthweight as compared to only 7.2% of babies born to nonsmokers. More specifically, infants born to smokers weigh on average 200 grams less than infants born to people who do not smoke. [20]
The nicotine in cigarette smoke constricts the blood vessels in the placenta and carbon monoxide, which is poisonous, enters the fetus' bloodstream, replacing some of the valuable oxygen molecules carried by hemoglobin in the red blood cells. Moreover, because the fetus cannot breathe the smoke out, it has to wait for the placenta to clear it. These effects account for the fact that, on average, babies born to smoking mothers are usually born too early and have a low birth weight (less than 2.5 kilograms or 5.5 pounds), making it more likely the baby will become ill or die. [21]
Premature and low birth weight babies face an increased risk of serious health problems as newborns have chronic lifelong disabilities such as cerebral palsy (a set of motor conditions causing physical disabilities), intellectual disabilities and learning problems.
If you are smoking during the first trimester (organogenesis stage); the period where the organs and system of the baby as developing will be affected. There is 50 – 80% chance of having a congenital defect to your unborn child [22]
Sudden infant death syndrome (SIDS) is the sudden death of an infant that is unexplainable by the infant's history. The death also remains unexplainable upon autopsy. Infants exposed to smoke, both during pregnancy and after birth, are found to be more at risk of SIDS due to the increased levels of nicotine often found in SIDS cases. Infants exposed to smoke during pregnancy are up to three times more likely to die of SIDS than children born to non-smoking mothers. [ quantify ] [23]
| Defect | Odds ratio |
|---|---|
| cardiovascular/heart defects | 1.09 |
| musculoskeletal defect | 1.16 |
| limb reduction defects | 1.26 |
| missing/extra digits | 1.18 |
| clubfoot | 1.28 |
| craniosynostosis | 1.33 |
| facial defects | 1.19 |
| eye defects | 1.25 |
| orofacial clefts | 1.28 |
| gastrointestinal defects | 1.27 |
| gastroschisis | 1.50 |
| anal atresia | 1.20 |
| hernia | 1.40 |
| undescended testes | 1.13 |
| hypospadias | 0.90 |
| skin defects | 0.82 |
Smoking can also cause other birth defects, reduced head circumference, altered brainstem development, altered lung structure, and cerebral palsy. Recently the U.S. Public Health Service reported that if all pregnant women in the United States stopped smoking, there would be an estimated 11% reduction in stillbirths and a 5% reduction in newborn deaths. [20]
A recent study has proposed that maternal smoking during pregnancy can lead to future teenage obesity. While no significant differences could be found between young teenagers with smoking mothers as compared to young teenagers with nonsmoking mothers, older teenagers with smoking mothers were found to have on average 26% more body fat and 33% more abdominal fat than similar aged teenagers with non-smoking mothers. This increase in body fat may result from the effects of smoking during pregnancy, which is thought to impact fetal genetic programming in relation to obesity. While the exact mechanism for this difference is currently unknown, studies conducted on animals have indicated that nicotine may affect brain functions that deal with eating impulses and energy metabolism. These differences appear to have a significant effect on the maintenance of a healthy, normal weight. As a result of this alteration to brain function, teenage obesity can in turn lead to a variety of health problems including diabetes (a condition in which the affected individual's blood glucose level is too high and the body is unable to regulate it), hypertension (high blood pressure), and cardiovascular disease (any condition related to the heart but most commonly the thickening of arteries due to excess fat build-up). [25]
According to a 2010 study published in the European Journal of Pediatrics , the cessation of maternal smoking during any point during pregnancy reduces the risk of negative pregnancy outcomes when compared to smoking throughout the entire nine months of pregnancy, especially if it is done within the first trimester. The study found that expectant mothers who smoke at any time during the first trimester increase the risk that their child will develop birth defects, particularly congenital heart defects than expectant mothers who have never smoked. The study found that the risk posed to the expectant mother's child increases both with the quantity of cigarettes smoked, as well as the length of time during pregnancy during which the mother continues to smoke. This, per the study, renders a more positive outcome for women who cease smoking for the remainder of their pregnancy relative to women who continue to smoke. [13]
There are many resources to help pregnant women quit smoking such as counseling and drug therapies. For non-pregnant smokers, an often-recommended aid to quitting smoking is through the use of nicotine replacement therapy (NRT) in the form of patches, gum, inhalers, lozenges, sprays or sublingual tablets. NRT, however, delivers nicotine to the expectant mother's child in utero . For some pregnant smokers, NRT might still be the most beneficial and helpful solution to quit smoking. Research in the UK has also shown that e-cigarettes could be more effective than nicotine patches, and because of this, could lead to better pregnancy outcomes. [26] [27] It is important that smokers talk to doctor to determine the best course of action on an individual basis. [28]
Infants exposed to smoke, both during pregnancy and after birth, are found to be more at risk of sudden infant death syndrome (SIDS). [23]
If one does continue to smoke after giving birth, however, it is still more beneficial to breastfeed than to completely avoid this practice altogether. There is evidence that breastfeeding offers protection against many infectious diseases, especially diarrhea. Even in babies exposed to the harmful effects of nicotine through breast milk, the likelihood of acute respiratory illness is significantly diminished when compared to infants whose mothers smoked but were formula fed. [29] Regardless, the benefits of breastfeeding outweigh the risks of nicotine exposure.
Passive smoking is associated with many risks to children, including, sudden infant death syndrome (SIDS), [30] [31] asthma, [32] [33] lung infections, [34] [35] [36] [37] impaired respiratory function and slowed lung growth, [10] Crohn's disease, [38] learning difficulties and neurobehavioral effects, [39] [40] an increase in tooth decay, [41] and an increased risk of middle ear infections. [42] [43] [1]
A grandmother who smokes during her daughter's pregnancy transmits an increased risk of asthma to her grandchildren, even if the second-generation mother does not smoke. [44] The multigenerational epigenetic effect of nicotine on lung function has already been demonstrated. [44]
Nicotine is a naturally produced alkaloid in the nightshade family of plants and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for smoking cessation to relieve withdrawal symptoms. Nicotine acts as a receptor agonist at most nicotinic acetylcholine receptors (nAChRs), except at two nicotinic receptor subunits where it acts as a receptor antagonist.
Smoking cessation, usually called quitting smoking or stopping smoking, is the process of discontinuing tobacco smoking. Tobacco smoke contains nicotine, which is addictive and can cause dependence. As a result, nicotine withdrawal often makes the process of quitting difficult.
Passive smoking is the inhalation of tobacco smoke, called passive smoke, secondhand smoke (SHS) or environmental tobacco smoke (ETS), by individuals other than the active smoker. It occurs when tobacco smoke diffuses into the surrounding atmosphere as an aerosol pollutant, which leads to its inhalation by nearby bystanders within the same environment. Exposure to secondhand tobacco smoke causes many of the same diseases caused by active smoking, although to a lower prevalence due to the reduced concentration of smoke that enters the airway.
Nicotine replacement therapy (NRT) is a medically approved way to treat people with tobacco use disorder by taking nicotine through means other than tobacco. It is used to help with quitting smoking or stopping chewing tobacco. It increases the chance of quitting tobacco smoking by about 55%. Often it is used along with other behavioral techniques. NRT has also been used to treat ulcerative colitis. Types of NRT include the adhesive patch, chewing gum, lozenges, nose spray, and inhaler. The use of multiple types of NRT at a time may increase effectiveness.
Placental abruption is when the placenta separates early from the uterus, in other words separates before childbirth. It occurs most commonly around 25 weeks of pregnancy. Symptoms may include vaginal bleeding, lower abdominal pain, and dangerously low blood pressure. Complications for the mother can include disseminated intravascular coagulopathy and kidney failure. Complications for the baby can include fetal distress, low birthweight, preterm delivery, and stillbirth.
Nicotine gum is a chewing gum containing the active ingredient nicotine polacrilex. It is a type of nicotine replacement therapy (NRT) used alone or in combination with other pharmacotherapy for smoking cessation and for quitting smokeless tobacco.
Environmental toxicants and fetal development is the impact of different toxic substances from the environment on the development of the fetus. This article deals with potential adverse effects of environmental toxicants on the prenatal development of both the embryo or fetus, as well as pregnancy complications. The human embryo or fetus is relatively susceptible to impact from adverse conditions within the mother's environment. Substandard fetal conditions often cause various degrees of developmental delays, both physical and mental, for the growing baby. Although some variables do occur as a result of genetic conditions pertaining to the father, a great many are directly brought about from environmental toxins that the mother is exposed to.
Birth weight is the body weight of a baby at their birth. The average birth weight in babies of European and African descent is 3.5 kilograms (7.7 lb), with the normative range between 2.5 and 4.0 kilograms. On average, babies of Asian descent weigh about 3.25 kilograms (7.2 lb). The prevalence of low birth weight has changed over time. Trends show a slight decrease from 7.9% (1970) to 6.8% (1980), then a slight increase to 8.3% (2006), to the current levels of 8.2% (2016). The prevalence of low birth weights has trended slightly upward from 2012 to the present.
Prenatal development includes the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal development until birth.
Complications of pregnancy are health problems that are related to, or arise during pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal disorders. While some complications improve or are fully resolved after pregnancy, some may lead to lasting effects, morbidity, or in the most severe cases, maternal or fetal mortality.
Tobacco products, especially when smoked or used orally, have negative effects on human health. Researchers have addressed concerns about these effects for a long time. They have focused primarily on cigarette smoking.
Intrauterine hypoxia occurs when the fetus is deprived of an adequate supply of oxygen. It may be due to a variety of reasons such as prolapse or occlusion of the umbilical cord, placental infarction, maternal diabetes and maternal smoking. Intrauterine growth restriction may cause or be the result of hypoxia. Intrauterine hypoxia can cause cellular damage that occurs within the central nervous system. This results in an increased mortality rate, including an increased risk of sudden infant death syndrome (SIDS). Oxygen deprivation in the fetus and neonate have been implicated as either a primary or as a contributing risk factor in numerous neurological and neuropsychiatric disorders such as epilepsy, attention deficit hyperactivity disorder, eating disorders and cerebral palsy.
Nicotine dependence is a state of dependence upon nicotine. Nicotine dependence is a chronic, relapsing disease defined as a compulsive craving to use the drug, despite social consequences, loss of control over drug intake, and emergence of withdrawal symptoms. Tolerance is another component of drug dependence. Nicotine dependence develops over time as a person continues to use nicotine. The most commonly used tobacco product is cigarettes, but all forms of tobacco use and e-cigarette use can cause dependence. Nicotine dependence is a serious public health problem because it leads to continued tobacco use, which is one of the leading preventable causes of death worldwide, causing more than 8 million deaths per year.
Women should speak to their doctor or healthcare professional before starting or stopping any medications while pregnant. Non-essential drugs and medications should be avoided while pregnant. Tobacco, alcohol, marijuana, and illicit drug use while pregnant may be dangerous for the unborn baby and may lead to severe health problems and/or birth defects. Even small amounts of alcohol, tobacco, and marijuana have not been proven to be safe when taken while pregnant. In some cases, for example, if the mother has epilepsy or diabetes, the risk of stopping a medication may be worse than risks associated with taking the medication while pregnant. The mother's healthcare professional will help make these decisions about the safest way to protect the health of both the mother and unborn child. In addition to medications and substances, some dietary supplements are important for a healthy pregnancy, however, others may cause harm to the unborn child.
Tobacco smoking has serious negative effects on the body. A wide variety of diseases and medical phenomena affect the sexes differently, and the same holds true for the effects of tobacco. Since the proliferation of tobacco, many cultures have viewed smoking as a masculine vice, and as such the majority of research into the specific differences between men and women with regards to the effects of tobacco have only been studied in-depth in recent years.
Circumvallate placenta is a rare condition affecting about 1-2% of pregnancies, in which the amnion and chorion fetal membranes essentially "double back" on the fetal side around the edges of the placenta. After delivery, a circumvallate placenta has a thick ring of membranes on its fetal surface. Circumvallate placenta is a placental morphological abnormality associated with increased fetal morbidity and mortality due to the restricted availability of nutrients and oxygen to the developing fetus.
Prenatal cocaine exposure (PCE), theorized in the 1970s, occurs when a pregnant woman uses cocaine and thereby exposes her fetus to the drug. Babies whose mothers used cocaine while pregnant supposedly have increased risk of several different health issues during growth and development.
Epigenetic effects of smoking concerns how epigenetics contributes to the deleterious effects of smoking. Cigarette smoking has been found to affect global epigenetic regulation of transcription across tissue types. Studies have shown differences in epigenetic markers like DNA methylation, histone modifications and miRNA expression between smokers and non-smokers. Similar differences exist in children whose mothers smoked during pregnancy. These epigenetic effects are thought to be linked to many of negative health effects associated with smoking.
Fetal programming, also known as prenatal programming, is the theory that environmental cues experienced during fetal development play a seminal role in determining health trajectories across the lifespan.
Exposure to nicotine, from conventional or electronic cigarettes during adolescence can impair the developing human brain. E-cigarette use is recognized as a substantial threat to adolescent behavioral health. The use of tobacco products, no matter what type, is almost always started and established during adolescence when the developing brain is most vulnerable to nicotine addiction. Young people's brains build synapses faster than adult brains. Because addiction is a form of learning, adolescents can get addicted more easily than adults. The nicotine in e-cigarettes can also prime the adolescent brain for addiction to other drugs such as cocaine. Exposure to nicotine and its great risk of developing an addiction, are areas of significant concern.
This article incorporates text available under the CC BY 4.0 license.
