Introduction
Despite the erection of a smoking ban in Ireland, about 20% of the population still continues to smoke.
In contrast to alcohol, marijuana and other illicit drugs, tobacco use is less likely to decline as the pregnancy progresses ((Day et al. 2000; Cornelius et al. 1995). The reason for this is that nicotine is addictive and its difficult for woman who have been smoking for some years to suddenly stop smoking for 9 to 12 months due to pregnancy. Some woman resort to nicotine replacement therapy(NRT) to stop them from smoking during pregnancy but this NRT still contains nicotine and it so the hazard posed to the baby is not reduced. E-cigarettes are also not advisable for pregnant woman as well . The aim of e-cigarettes originally was to reduce the nicotine intake and harmful chemicals; however, the development of e-cigarettes has led to an increase in nicotine delivery in the newer generations of these devices. This means that users are able to maximize nicotine delivery by altering their voltage on them and using e- cigarettes more frequently ;the impact of this is that exposure may be greater and addiction to nicotine may become more intense (Vansickel & Eissenberg, 2013). From all this we can conclude that abstinence from smoking may be the only solution for pregnant woman however this is difficult for woman who smoke everyday to achieve.
Relevant statistics
From the second graph we can see that 20.2% of females smoke as of dec 2013. The age group of 25-34 is when most woman have children and as seen from the first graph the prevalence of those who smoke in that age group is higher – 28%. The percentage of those who smoke between the age of 18-24 is 31%. We can conclude from this that roughly 30% of Irish woman tend to smoke before, during or after their pregnancy and this is a serious health issue because smoking does tend to have detrimental effects on the fetus.
Diagram 1 Diagram 2
Effects of smoking on pregnancy.
Maternal smoking causes different problems during each stage of pregnancy starting from preconception,conception, first trimester of pregnancy, last trimester of pregnancy, delivery and overall fetal development.
Smoking can first of all make it difficult for woman to conceive children and even after conception there is a high chance of miscarriages happening. Infertility rates are higher in smokers compared with non-smokers (Li et al., 1990), fecundability rates are reduced (Curtis et al., 1997), time to conception is increased (Linn et al., 1982; Olsen et al., 1983).Secondly, smoking can result in mothers giving birth to children born with low birth weight (Cope, 2014) .The reason for this is that nicotine is a vasoconstrictor and this means less blood flows to the baby in the first place.On top of that, carbon monoxide enters the baby’s bloodstream as well when the mother smokes, thus lowering the oxygen concentration that the baby should get for health development which result in slower growth and lower birth weight. Studies have shown that smoking increases the chances of the amniotic sac being ruptured prematurely which means labour will be induced even before the child has fully developed (Cope, 2014). So premature delivery is another complication associated with pregnancy. The reduction in infant weight is not because of premature child delivery as infants of smokers exhibit growth retardation during all gestation stages (NCI 1999). In a study of neonatal body composition, prenatal tobacco exposure was shown to correlate with less fat-free mass in the foetus and this was measured using total body electrical conductivity (Lindsay et al. 1997).
Smoking can also cause complications during childbirth. The placenta can separate from the attachment site prematurely causing internal bleeding which is hazardous to both fetus and mother. Placental previa can occur where the placenta is present in the lowest portion of the uterus thus covering the opening to the cervix causing the baby to born via caesarean surgery. So in general we can conclude that smoking results in abnormalities in the amniotic sac and placenta both of which are important to fetal development.
Though prompt medical intervention can ensure that the baby recovers quickly enough from all of these complications, there are other problems which are more serious and have long lasting impact on the fetus.
Smoking during pregnancy leads to high chances of Sudden Infant Death Syndrome(National Cancer Institute [NCI] 1999) where infants die suddenly and the cause of death is unknown. Autopsy results reveal that infants with increased levels of nicotine in their blood often die. Nicotine has the ability to cross the placenta and enter the baby’s bloodstream affecting the cardiovascular and central nervous systems (CNS) (Stillman et al. 1986). Other constituents of tobacco smoke such as cadmium and toluene have also been shown to reduce fetal growth rate (Office of Environmental Health Hazard Assesment [OEHHA] 1996). Babies can also be born with permanent birth defects. The most common ones that are associated with smoking are clubfoot, lower head and chest circumference and shorter birth length.
Interestingly, in another study Zaren and colleagues (2000) reported that prenatal exposure to smoke harms the male fetus more than the female fetus. In this study, fetuses of smoking mothers were measured by sonograms at weeks 17, 25, 33, and 37. Boys born to heavy-smoking mothers had lower weight gain, lower fat content, and smaller head circumferences when compared with girls of heavy smoking mothers.
Apart from the direct problems that the baby might get if the mother smokes, indirect problems include a weak lung and irritated airways which translate into respiratory illnesses ( Carlsen , 2008) for the child later on in life. Lastly the fetus has higher chances of getting cancer specifically lung, oral and nasal cancer (Stjernfeldt et al. 1986). Apart from maternal smoking, inhalation of smoke by a pregnant mother from somebody else (passive smoking) also serves to exacerbate the above mentioned problems.
Overall, we can conclude that smoking harms the fetus at all stages of pregnancy from conception to delivery and can potentially leave long lasting health problems on the fetus. Therefore mothers should avoid smoking before, during and after pregnancy. It is also worth noting that there are no other viable alternatives available for mothers to who are not able to abstain from smoking as NRTs and electronic cigarettes also contain nicotine which harms the fetus. This is one area that public authorities can look into in order to ensure that pregnant mothers who struggle to give up smoking can still find a way to reduce the risk to their fetus.